The Ultimate Guide of Metal Stamping

Metal stamping has become an indispensable part of industrialized manufacturing due to its efficiency in bulk and high-speed production. This metal pressing technique is utilized to stamp sheet metals into interior and exterior parts of the prescribed size and shape. This write-up includes A to Z technical information on metal stamping. 

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Metal Stamping: A Brief Introduction 

Sheet metal pressing or stamping is a metal forming process to transform sheet metal into a specific shape and dimension, utilizing indentation. A shape-specific die and design-suited press are used to stamp the sheet metal into various forms. The pressure applied by the press deforms the sheet metal and shears it into the die shape. Flat metal sheets that are fed into the machines are referred to as blanks.

Figure 1: Metal Stamping 

Origin of Metal Stamping: Replacing Die Forging 

The origin of metal pressing dates back to the 7th century B.C. Lydians, a society in a Western Asian region (present-day Turkey), started to stamp metals to produce coins. They halted the process and developed a hammering technique for carving metal coins. 

A German craftsman, Max Schwab, resumed the metal stamping process and worked to increase its efficiency in . He designed a screw machine to provide the enormous pressure required to stamp metal sheets. 

Around , a German manufacturer lent this idea and utilized it to produce body parts for his bicycle company. Soon, the technique took off, and researchers started to increase its production capacity. 

Henry Ford brought a revolutionary change in stamping and improved the tolerance and precision scale. Right now, the metal pressing industry has achieved higher precision, accuracy, and efficiency. The stamped metal parts are used in all industries worldwide.

Figure 2: Metal Stamping in Old Days

Why Do We Use Sheet Metal Stamping? 

Stamping metal sheets has become a billion-dollar industry. The goal of this metal-forming process is to produce metal parts with specific shapes, designs, and dimensions. Due to the recent developments in stamping techniques, the stamped products are manufactured with precision and low tolerance. Besides, metal pressing is cost-effective, and bulk production is possible in a shorter time frame. 

Considering all the benefits, industries have become dependent on metal stamping to manufacture their instrumental body parts. With the introduction of the latest technologies, metal stamping is getting more accurate in producing intricate parts. Hence, demand for it is booming year after year. 

Metal Stamping Basics: How Does Metal Stamping Process Work?

A 2D sheet is converted into a 3D curved surface in the metal pressing process. The entire operation has five basic parts. 

• Die Design: The stamping process starts with designing the die or the metal shaper. CAD software is used for precise and intricate designs. The next step is manufacturing the metal stamping die with a CNC machine and laser cutting. 
• Material Preparation: A metal sheet suitable for the application and fabrication method is selected. Later, it is cut into shorter lengths for convenience in handling. A metal coil is used for progressive die stamping. 
• Feeding: The machinery and parameters are adjusted. The metal sheet is then fed into the automated workstation setup. 
• Stamping Operation: In this main operation, a tonnage of pressure is applied to the sheet metal to deform its shape. Multiple stamping operations might be carried out on the sheet depending on the demand. 
• Finishing and Post Processing: The last stage is dedicated to heat treating or surface treating the stamped parts, if necessary. 

Tuling has years of experience in manufacturing customized stamping metal parts. Contact us to learn more about our operational stamping business.

Figure 3 Basics of Metal Stamping Process

Metal Stamping and Forming: Differences 

People often confuse metal stamping and metal forming processes. Though these two terms have some similarities, they are very different. 

Technically speaking, metal stamping falls under the metal forming category. In this process, operations like blanking, cutting, piercing, drawing, bending, flanging, etc., are involved, depending on the design demands. Stamping press and die are used in metal pressing. 

Metal forming, on the other hand, is a broader term. Drawing, forging, casting, extrusion, and all other fabrication processes fall under this term.  In metal forming, the pressure itself is enough to deform and shape the metal. Here, cutting, piercing, bending, etc., operations are useless. 

Usually, metal forming is required to manufacture complex designs that can not be done alone with metal stamping. 

Types of Metal Stamping Techniques 

Metal stamping techniques can be classified in different ways. The main six types are mentioned below: 

Progressive Die Stamping 

Progressive die metal pressing is by far the most popular stamping technique. It is a manufacturing method in which the metal is automatically passed through a series of forming dies, each assigned a specific task. 

In simple terms, a metal coil is fed into the mold, and the automated series of operations starts. A punching die makes holes in the metal coil and passes it to the next station. There, the metal might be bent or trimmed. The metal coil gets closer to its final shape with each passing station. At the final station, the finished part is separated from the metal strip. As the finished product leaves the station, a new metal coil is instantly assigned for the first operation. 

The entire process of progressive die stamping is automated. Before each operation, the designs are positioned in alignment with a guide post, which ensures precision in the stamped part. 

In progressive die stamping, each step runs continuously without a break. Hence, it is suitable for manufacturing large orders of repeatable parts in a short time. 

Transfer Die Stamping 

Transfer die stamping is similar to progressive die stamping. However, there are fundamental differences between these two methods. 

In this process, the metal part is separated from the metal strip at the beginning. Each part is treated as an individual unit. Therefore, metal wastage during the bypassing is drastically reduced.

Just like progressive die stamping, the metal strip is passed through multiple workstations to carry out our specific operation in transfer die stamping. But here, the feeder does not push the metal automatically on the conveyor. 

In transfer stamping, no station is ever at a break. A new metal is fed as soon as the existing one leaves the station. Thus, the process reduces the operation run time. The stamping process is highly cost-effective as it does not require a sheet guide. It allows the use of one or more dies and eventually cuts down the tooling costs. 

The transfer die metal stamping is utilized to manufacture intricate designs. For example, knurls, threads, knobs, etc. It is also assigned to produce tube and deep-drawing metal components. 

Compound Stamping 

In compound stamping, multiple operations, for example, cutting, punching, bending, etc., can be achieved with just one stroke. This process can produce complex parts with tight tolerance, like clamps, retainers, shields, brackets, seals, etc. However, the main focus of compound stamping is to manufacture simple, flat components like washers. Progressive die stamping is better suited to pull off intricate designs. 

Compound stamping is cost-effective and faster for high-volume production of repeated designs. However, manufacturing intricate components can be costly and time-consuming. 

Four Slide Stamping

As the name implies, four-slide stamping uses four motor-driven slides, each at a 90-degree angle to the others. 

When you start the motor, the bevel gear and the camshaft transmit the power to the slide blocks. During the operation, the four slides reciprocate in sequence and pressurize the mold, bringing the final shape. Here, two slides strike vertically, and two blocks work horizontally, negating the necessity of dies. With four sliding arrangements, structures with more than 90 degrees can be fabricated. The four-slide stamping can be upgraded to a multi-slide stamping process. 

Four-slide stamping is relatively low cost, and a high volume of repeated components can be manufactured with no intervention. The technique is more popular for producing structures with tetrahedral bends.

Figure 4 Progressive Stamping and Fourslide Stamping

Fine Blanking

Fine-edge blanking, or fine blanking, is a stamping technique that operates on the principle of mechanical or hydraulic pressure effect. This process is extremely valuable for manufacturing smooth-edged components with high accuracy. 

In fine blanking, the workpiece is clamped with the station first, and then the tonnage of pressure is applied. The operation ends with the ejection of the finished product. 

The pressure required for fine-edge blanking is usually higher. This technique lowers the chances of surface defects and fractures. Fine blanking is a cold working process, and it can be done in a single step, which cuts the overall fabrication cost. 

Deep Drawing Stamping 

In deep drawing stamping, the sheet metal is pulled with a punch to give it an appropriate shape. Here, the depth of the drawn part must exceed the length of the diameter. A 2:1 or 3:1 height-to-width ratio can be achieved with deep drawing. This stamping technique is utilized to manufacture versatile components with complex detailing and an exceptional degree of accuracy. It is a cost-effective alternative to the turning process. 

Process Temperature Stamping 

The temperature process stamping can be categorized into two classes. Such as, 

1. Hot stamping 
2. Cold stamping 

Hot stamping: A higher pressure is applied to deform the metal sheet in cold stamping. The pressure requirement can be deduced if you heat the metal sheet beforehand. It eases the deformation and shaping process. This is called hot stamping. 

In hot stamping, the metal sheet is heated in advance, which changes its microstructure. For example, at low temperatures, the metal crystals are at ferrite or pearlite orientation (harder and brittle). With temperature, it is transformed into austenite (softer and ductile). As a result, deforming the sheet demands less pressure. 

Quenching the hot metal part will form a martensitic microstructure, adding hardness and strength to the components. Repeating the heating and cooling cycle allows you to customize the strength and hardness profile of the parts. The hot stamping technique produces hard and strong metal parts that can absorb high-impact energy without fracturing.

Figure 5 Hot Stamping Process

Cold Stamping is the typical stamping process we follow. As there is no heat involved, the mechanical profile of the metal components produced is constant. The cold stamping technique is simpler and less complicated. 

Short Run Stamping & Long Run Stamping 

Short-run stamping is dedicated to producing stamped parts in small volumes. It is utilized in manufacturing prototypes or components with exceptional accuracy. On the other hand, in the long run, stamping and stamped products are produced in bulk. More details are discussed below, 

Short Run Stamping: When you want to manufacture less than small parts or less than 100 big components, short-run stamping is suitable. You get rapid production with high precision. The tooling cost is lower as the operation runs short, and there is minimum wear or tear. 

As you manufacture in small lots, customization and modification in design are possible. Though the tooling cost is low, the price of each component is higher due to the lot size. Short-run stamping is suitable for prototype component designing.

Long Run Stamping: Long run stamping should be your preference when you want to manufacture more than small parts or more than 100 big components. Because of the bulk production, it takes more time to finish the operation. The tooling cost is higher as the operation runs for longer. Tools designed for durable and long-term use are used here. 

Due to the large production quantity, the scope of customization and modification in design is limited. Though the tooling cost is high, the price of each component is economical. This technique is better suited for market-standard industrial body parts.

Metal Stamping Process Step-by-Step

In metal stamping, the sheet metal might undergo a series of operations, depending on the design. Each operation is counted as one step in forming the final product. Engineers calculate a reasonable number of steps required for producing one single component. Including too many steps will only increase the costing. Common metal pressing operations are discussed below, 

1. Blanking

It is the first step in the metal stamping operations. In blanking, a small material portion is cut from the large sheet for convenience. Usually, the outer profile of the stamped metal component is cut in this step. The process is suitable for stamping small and medium metal parts in large or small volumes. The final product in blanking has rough edges and requires deburring or other finishing operations. 

2. Punching 

This process is similar to blanking. The only difference here is that punching creates an inner profile utilizing a shearing force. For example, holes and slots of different sizes and shapes are punched out in this stage. 

3. Piercing 

Piercing is the same as punching. However, unlike punching, the piercing path is suitable for producing metal parts with complex designs and high accuracy. The tool setups are such that the holes are punched out in a rapid motion to avoid deformation and defects. Piercing tools are made of high-carbon steel and undergo regular maintenance to provide precision cutting. Lancing, shaving, and nibbling are a few types of piercing. 

4. Bending 

In bending, the metal sheet is placed on a die, and a ram pushes against the blank to produce a desired angle (L/U/V). Bending is one of the most important metal-pressing steps to achieve complex structures in components. Bending after punching operations can induce defects in the products due to springback and stress concentration effects. To avoid the unwanted impacts, bendings must be carried out after drawing. 

5. Bottoming 

Bottoming is a press-bending operation. Here, a strong pressure drives the sheet into a fitted die to produce a permanent and precise bend. Unlike other bending operations, bottoming only supports V bends. 

6. Air bending 

Like bottoming, the sheet metal is forced into a V-shaped die in air bending. However, in air bending, the die does not come in close contact with the sheets. As a result, pulling off tight tolerance is not possible with air bending. Angle accuracy can be maintained by adjusting the clearance. Air bending is economical because it does not require matching tools and can be operated at a low tonnage power. 

7. Lancing 

In lancing, the sheet metals are cut in a single line or slit without any scrap production. This operation creates a metal flow, preventing any fractures. It is used to produce components with hook shapes or parts vents and tabs. 

8. Extrusion Forming 

Metal stamp forming is particularly used to produce components with multiple bends. In many cases, the forming is followed by a drawing operation. Extrusion forming is mandatory to manufacture high-aspect-ratio parts with changing thicknesses. 

9. Drawing 

In the drawing, the sheet metal is hit with a punch that matches the die’s cross-section. As the punch is pushed, the sheet metal is drawn in the die’s depth, taking the desired shape. Drawing stamping is necessary to produce components with thin walls and irregular shapes. The accuracy of drawing stamping is less than that of deep drawing. 

10. Flanging 

Unlike other bending operations, flanging only focuses on bending small workpieces at a curved angle. These flares create connections for fastening assembly. Flanging is well-suited for manufacturing components with high accuracy.  

11. Embossing 

Important patterns and features are highlighted on the metal part surfaces with embossing. Here, a blank metal sheet is pressed against a die containing the desired patterns. In short, it provides a raised or three-dimensional effect on the surface. Aluminum is suitable for embossing stamping because of its excellent ductility and machinability. 

12. Coining 

Coining is usually done in the finishing stage. It is a cold-forming technique where the sheet metal is stamped using two dies from both sides. The process produces fine details with less material displacement. Coining manufactured component surfaces exhibit resistance against impact and abrasion. 

13. Pinch Trimming 

The metal piece is separated from the excess materials with bottom strokes in pinch trimming. This trimming can achieve a clean and precise cut. It is usually carried out after another main operation, such as drawing, punching, bending, etc. 

Factors to Consider When Stamping Metal

You need to consider several parameters to pull off successful and quality stamping metal parts. The factors are as such, 

1. Metal Thickness: Cold stamping can handle thick metal bars of 3 inches. Hot stamping techniques are more suitable for thicker metal sheets. 
2. Metal Selection: You can use soft and ductile metal sheets of aluminum or hard metals like stainless steel for pressing. The operational pressure requirement for cutting or bending these metals is different. 
3. Tooling Design Detailing: Detailing is mandatory in stamping tooling designs. Recheck the dimensions, clearance, and tight tolerance of the dies. Otherwise, you can not manufacture metal-stamped parts accurately. 
4. Friction & Lubrication: The higher friction between the punch and punch might lead to deformation due to heat generation. Calculating the fraction coefficient and using an appropriate lubricant will reduce wear and damage. 
5. Operational Parameter: Calculate optimal pressure, temperature, springback potential, impact formability, and material flow rate into the die. You can avoid bulging, wrinkling, and wrapping-like defects by influencing their deformational habits. 
6. Product Shape: Depending on the geometry of the final component, you need to choose a suitable stamping path. For example, compound stamping is perfect for producing flat and simple shapes. Likewise, progressive die stamping is assigned to manufacture complex shapes with high precision. 
7. Machine Setups: It is absolutely necessary to adjust the machinery and guiding posts according to your stamping method and requirements. Before starting the operation, consider mesh size, punching speed, pressure point, tonnage, and all other details. 

Metal Stamping Industry Applications

Stamped metal parts have a wide spectrum of application. Hence, due to the flexibility and customization possibility, you can serve literally any product industry with the metal stamping service. Some common industrial application of metal stamping are, 

Industry  Stamped Metal Parts  Automotive  Brackets, engine components, valve covers, car body parts, etc. Electric  PCB shielding, connectors, sinks, springs, clips, etc. Aerospace and Space  Special brackets and panels  Construction  Brackets, connectors, supports, fasteners, etc. Medical  Implants and surgical equipment Defense and Military  Brackets and mounts, weapon components, micro-prototypes, etc.  Energy  Hardware, fasteners, bracket mounts, etc. Telecommunication  EMI shields, springs and clips, busbars, washers, etc. Consumer Goods Hardware, tools, toys, etc.  Apparel  Hangers, needles and pins, eyelets and grommets, etc. Furniture  Shelf support, light fixture, drawer slides, etc.

Figure 6 Metal Stamping Products

Sheet Metal Stamping Design

A flawless design is crucial to stamping tight tolerance and accurate metal parts. Hence, anyone linked to this industry must understand the basics of metal pressing designing. For your convenience, I have broken down the principle, feature details, and operational terms of sheet pressing here. 

Blank Profile

Advanced tooling technology allows stamping metal sheets with a minimum of 0.001 inch thickness. With special dies, bars with a thickness around 3 inches can also be stamped. Ideally, the blank corner radii should equal to at least half of material thickness. 

Edge Conditions

The distance between edges and holes or slots should be at least 2x the material thickness. Edge condition also implies that the clearance between the punch and die must be 8% to 10% of the material thickness. Generally, a tight tolerance is achievable with softer and ductile metal sheets. Failing to satisfy edge conditions leads to bulging and deformation. 

Hole Piercing 

For stamping ductile materials like aluminum, the minimum diameter of holes should be at least 1.2x the thickness of the material. Again, for materials with higher tensile strengths like stainless strength, a minimum diameter of 2x the material thickness is recommended. 

Slots

Ideally, a slot width should be at least 1.5x the material thickness. With specialized processing tools, smaller diameters can be achieved. But there is always a risk of failure. Again, the slot length must not exceed 5x the width of the feature. 

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Spacing Between Holes and Other Features

The spacing between bend and holes should be the bend radius plus 2.5 times the material’s thickness. In case the hole is less than 2.5mm in width or diameter, maintain a spacing of a minimum of 2x the material’s thickness plus the bend radius. For holes more than 2.5mm in width or diameter, the ideal spacing is the bend radius plus 2.5x the material thickness.

For edge gaps, a minimum space of 1.5 times the thickness is necessary when the adjacent edge length is 10x the material thickness. For punched diameters less than 5 times the thickness, maintain a spacing of twice the thickness.

Notches & Tabs 

The ideal width of notches and tabs is 1.5 times the thickness of the material. A smaller width than this scale causes breakage due to a large concentrated force. 

Corners 

Corners in the blank should have a radius of at least half the material’s thickness. Sharp corners are recommended only when the material is 1.5mm or less in thickness.

Squareness, Flatness, and L-Shaped Parts

When stamping a component at 90 degrees, leave room for 1 degree plus or minus variation clearance. Flatness in metal sheets less than 0.003 inch is a costly operation. A bend relief notch should be introduced for manufacturing L-shaped or other angled body parts to avoid fractures.

Figure 7 Metal Stamping Design Fundamentals

Custom Sheet Metal Stamping Services at Tuling 

At Tuling, we are strictly dedicated to providing our customers with satisfactory service. Hence, you have launched A to Z metal stamping solutions under one roof. Our customization services include, 

Ideation 

In the beginning, we call meetings to discuss your project goals and requirements. Our project lead will then present you with the best and most economical techniques for stamping your metal parts. 

Design 

We have an experienced team who can assist you in designing your industry-specific stamped components. At Tuling, our engineers use CAD/ CAM and the latest software tools to meet the design requirements. 

Production 

After the design stage, we move on to producing a custom die. Our quality assurance team ensures specific area clearance and tool efficiency. Tuling has advanced stamping tooling technologies. Our stamped components have tight clearance and exceptional precision. 

Implementation 

Tuling also does the assembly work on the client’s request. Only after cross-checking the manufactured parts with the requested requirement do we dispatch our orders. 

Metal Stamping Materials: The Available Options

Though we have numerous metal options available, all of those are not suitable for metal stamping. The metal must have a certain degree of machinability and flexibility. You find the most suitable and economical metal options for your stamping operations. 

Importance of Selecting Right Materials 

It is crucial to choose the right metal for your stamping operation because, 

• Wrong material selection will increase the operational cost and material wastage. 
• A metal unfit for the stamping process can not fulfill its demands. 
• Metal sheets that can not withstand pressure will include defects and deformation by the time the operation is done. As a result, you can not expect durability. 
• The final component can not stand on its functionality expectations. Hence, consider all the specifications, for example, conductivity, ductility, strength, etc., while selecting the metal. 
• Machinability, weldability, formability, etc., are not smooth if you choose the wrong material. Thus, you can not fulfill the design requirements. 

Types of Materials 

The available materials for metal stamping can be classified into two categories. Such as, 

1. Ferrous materials
2. Non-ferrous materials 

A brief introduction to these materials is given below, 

Ferrous Materials 

Carbon Steel: It is most commonly used in stamping metals. Two types of carbon steel are popular in the market. The low-carbon steel is soft and ductile. Due to its good machinability, this low-carbon steel is suitable for metal pressing. On the other hand, high-carbon steels are harder and harder to stamp. 

Galvanized Steel: This zinc-plated steel is corrosion and erosion-resistant. Hence, stamping components used in harsh environments are made of galvanized steel. 

Stainless Steel: With stainless steel, you can manufacture parts with high strength and high corrosion resistance. The machinability and mechanical profile of the steel can be tailor-made by controlling the chromium percentage. 

Cold-rolled Steel: It is easier to produce a smooth surface with controlled dimensions and accurate clearance with cold-rolled steel. This steel is rolled at room temperature. 

Non-Ferrous Materials 

Aluminum: Because of its lightweight, corrosion resistance, and excellent machinability, aluminum is commonly used in metal stamping. 

Copper: It is used to produce stamped electrical components with high electrical conductivity and corrosion resistance. 

Brass: For decorative parts with a glittery luster and moderate corrosion protection, brass metal stamped parts are used. 

Titanium: Generally, titanium is more costly compared to other stamping metals. It is used in producing parts for industries that prefer light but strong metals with high corrosion resistance.

Figure 8 Sheet Metals for Stamping

Surface Finishing of Stamped Metal Products 

In the final stage, the produced metal components undergo surface treatments. With this step, any impurities are removed from the surface, and the component is made visually aesthetic. Surface treatment can add a protection layer on the stamped parts to increase their longevity. Methods of surface finishing are, 

Uncoated Finishes

Type What It Offers  Mode of Application  Fine Polish  Mirror-like, high-gloss finish Abrasion of fine clothes  Buffing Smooth and bright surface Abrasive tools Blasting Hard and gritty finish  High pressure air gun  Tumbling  Smooth surface of a small metal part Grind in a high-frequency vibratory machine with abrasive media  Brushing Brush-lined finishing  Steel-bristle brush Honing and Lapping Unidirectional fine lines on the surface  Honing and lapping machine  Chemical Etching Uneven, rough texture  Chemical reactive solvent  Laser Beam Marking  Burning surface  Laser beam Deburring  Smooth and fine finish  Mechanical deburring, water jet deburring, thermal deburring, etc.

Figure 9 Deburring Metal Stamping Parts

Coated Finishes

Type What It Offers  Mode of Application  Paint  Moisture protection  Liquid paint or spray paint  Powder Coating  High-quality protective finish  Electrostatic process  Anodizing  Oxidized layers specialized for aluminum, titanium and magnesium  Electrical bath  Electroplating  Coating of another protective metal (zinc, brass, or chromium) Electrodeposition  E-coating  Durable and even thickness protective layer Dipping the component in a paint bath Galvanizing  Oxidized zinc layer Immersion in a molten zinc bath PVD/ CVD Wear and corrosion resistant surface Vapor chamber 

Metal Stamping Tools and Die Definition

In the metal stamping industry, stamping tools and dies are of the utmost importance. It is an industry practice to interchange the words ‘tool’ and ‘die.’ In stamping manufacturing, both the terms carry the same meaning. 

The stamping dies, or stamping tools, are precision hard tools (can be of a male/female pair). It is used to cut, bend, or shape sheet metal into desired shape. The cutting and forming parts of the dies are made of tool steel or hard, wear-resistant metals like carbides. 

Stamping die design is one of the first steps in metal stamping. Only with a quality stamping blueprint can accurate stamped components be produced. Tool designers utilize CAD to construct a fine die design.

Figure 10 Metal Stamping Die and Tool

Types of Stamping Tools and Dies

Stamping tooling can be divided into two main categories. Such as, 

1. Single-action tooling dies
2. Multiple action tooling dies 

In single tooling dies, a single element is created with a single-stage operation. Likewise, a multiple-action die is an operation where more than one component can be produced with a single stroke. 

The single die can further be divided into other types. Such as, 

1. Progressive Dies: These dies can perform more than one cutting operation in a single stroke. 
2. Transfer Dies: The operation in transfer dies usually starts with blanking. The metal piece passes station after station until it acquires the desired shape. 
3. Combination Dies: Metal cutting and forming operations can be performed together on combination dies. 
4. Compound Dies: These dies can carry out multiple cutting operations in one stroke. 

Tooling Metal Options 

Generally, steel is used to manufacture tools because of its hardness, wear resistance, and toughness. In metal stamping, steel tools are utilized for cutting, punching, and engraving purposes. Common steel tools are, 

Types of Tool Steels Applicable Situation  Cold Work Tool Steel  Cold forming operations  High Speed Tool Steels High-speed and large volume production Hot Work Tool Steels  High temperature manufacturing  Shock Resistance Tool Steels  Cold works where shock and impact resistance is necessary  Carbon Tool Steels  Short run manufacturing 

Stamping Manufacturing Process

Metal pressing is expensive due to the complexities. Heavy and expensive machinery is required to finish the entire operation. Each component gets the final shape after undergoing multiple stages. 

Machineries for Stamping 

CNC Tooling Design the punch and die blueprint with accuracy.  Wire EDM Punch out the outer profile of the blank.  Heat Treatment To increase the mechanical profile of the stamped component. Assembly To check the fitting, dimension, and precision.  

Stamping Machine Maintenance

Regular maintenance is crucial in stamping equipment. Otherwise, tool wearing can lead to accidents, breakdown of the machine, and production of defective pieces. The maintenance steps are, 

• Visual inspection of the tools
• Cleaning the debris
• Sharpening or replacing the worn-out and damaged parts
• Lubricating the dies and machines 

Cost Breakdown at Tuling 

Metal stamping is a comparatively cheaper option. At Tuling, we believe in transparency and offer our clients a complete breakdown of the possible expenses. Our main costings consist of, 

• Metal sheet cost
• Customized tool, die, and punch cost
• Operational costing
• Manual labor cost (design, inspection, assembly, etc.)
• Overhead cost 

The best part of a Tuling deal is that we do not take the entire payment in advance. You can seal the deal with a minimum percentage fee, and you can start the production. 

Types of Metal Stamping Machines

Variety is available in stamping machineries. Each one is designed to serve a specific purpose and application. Common types stamping machine types are mentioned below, 

• Mechanical Press: These machines are driven by mechanical means, such as a flywheel or eccentric. The principle here is to build up kinetic energy and release it to stamp the sheet. Mechanical presses are well-adapted because of their low cost, high speed and accuracy. These are ideal for large-volume production lines. Mechanical presses are more suited for operations like blanking, coining, and piercing. Hydraulic Presses 
• Hydraulic Presses: Oil or another high-viscosity liquid generates immense pressure in hydraulic press machines. These presses perform heavy-duty tasks like deep drawing and forging. 
• Servo Presses: These presses are powered by servo motors and can be used as a hydraulic press alternative. They can generate instant force and have excellent control over output shaft position and speed. Manufacturers serve presses where accuracy is mandatory and repeatability is critical, such as micro-stamping and prototyping. 
• Progressive Presses: These specialized toolings can perform multiple operations in one pass. Progressive stamping presses are suitable for producing smaller parts in large volumes. 
• Transfer Presses: Complex parts can be manufactured at a reasonable price with transfer presses. This pressing method offers versatility at a minimum tooling expense. It is used to produce tubes, frames, shells, knurls, ribs, etc. 
• Stamping Punch Press: A stamp press or punch press has the primary task of creating a punch or hole in the sheet metal. 
• Turret Punch Press: A rotating turret with multiple tool stations is used in turret presses. This method is assigned to basic tasks like punching and forming. 
• Pneumatic Presses: Air or gas is used to generate force in a pneumatic press. It is faster than the hydraulic press. Riveting, punching, and embossing-like tasks are carried out in the pneumatic press machines. 
• Coining Presses: In coin pressing, the observe and reverse dies are pressed against the punchlet to stamp out coins.
• Gap Presses: This is a specially designed pressing machine with 3 side working areas. These presses are also known as C-frame presses. The machine is only used to produce components with high precision and accuracy demands.

Figure 11 Hydraulic Press Machine

Production Floor Requirement for Metal Stamping 

Due to their heavy weight, stamping machines are placed on the first floor of manufacturing plants. The ground foundation must be stable enough to handle the huge impact force and operational vibration caused by the press machines. Stamping equipment kept on unstable flooring will lead to cracking and minor accidents. It is better to reinforce the floors and tailor-make the plant infrastructure to accommodate and operate metal stamping machines. 

Can You Reduce The Metal Stamping Cost?

Manufacturers can control the metal stamping operational costing with the following practices, 

1. Stock on material when the market rate is low. 
2. Instead of incorporating a rare alloy, incorporate a common and standard alternative.
3. Select a material with a higher cost-performance ratio. 
4. Consider all the factors and coefficients while designing the customized punch and die to cut any unwanted costs.
5. Follow a design guide and consult a tooling engineer to make a die and punch blueprint with proper bend radius, tab, hole, piercing, etc.
6. Well-optimize the tools and the machinery to boost production efficiency and reduce operational time. 
7. Choose the right stamping path with optimum automation opportunities. 
8. Reduce scrap production and metal wastage. 

Manufacturer Roles in a Stamping Project

Each manufacturer has its own style of running the operation. Here’s how we run the stamping business at Tuling, 

1. Our product designer scrutinizes your design and makes any changes after consulting you.
2. The tooling engineer predicts the efficiency and effectiveness of the design with simulation analysis.  
3. After the tool shop gathers the required metals and parts, the production team produces a dummy die and punch for your order lot.
4. The die and punch only get a green signal after the Quality engineer ticks all the requirements.
5. Next, the order will get into the process, and a project manager will look after the entire operation. He will also follow up on customer service and communicate with the client. His job also requires updating the technical, purchasing, and PMC departments about the project’s progress.

Advantages and Disadvantages of Metal Stamping 

Metal pressing has gained popularity due to its convenience and versatility. But this method is not perfect. You must weigh both pros and cons before selecting metal stamping for your industrial part production.

Advantages 

• Customization 
• Economical 
• Mass production 
• Small volume manufacturing 
• A high degree of accuracy
• Efficient and less time-consuming 
• High degree of strength and durability 
• Complex geometry production 

Disadvantages 

• High initial set-up cost
• Limited to stamp thin sheet metals
• Not fit for all metals 
• Metal wastage
• High cost of quality control 
• Regular maintenance 
• Expert handling 

Defects in Metal Stamping 

Minor irregularities in the stamping operation can lead to defects in the final product. Common metal stamping defects are, 

• Bending Damage: Bending stiff metals with low plasticity can lead to cracking. Bends parallel to grain flow direction cause large cracks.
• Hole Deformation: Hole punching is one of the first steps in the metal stamping operations. Not following the design guides and making holes near the edge can stretch or deform the holes during bending.
• Bulging: The metal strips bulge due to the spacing issue between the hole and the bent edge.
• Sharp Burrs: Metal-stamped products with cuts have sharp burrs and a blemished finish. This messes up the accurate dimension of the component.

Future of Metal Stamping 

Recent developments in metal stamping have made it possible to manufacture components with high accuracy. The introduction of sophisticated and high-tech equipment will automate the entire process, cutting manual labor. With an optimized operation, an increase in production is possible. Besides, more intricate parts can be manufactured with high precision. A chance is there that tool engineers and designers will utilize the potential of AI and take the quality of the stamping industry to the next level. 

Conclusion

Metal stamping is a tricky fabrication process. The entire project can turn into a disaster without expert guidance and observation. Here, at Tuling, you will find a combination of expertise, manpower, and upgraded machinery. So, contact us and let us handle your project in the best way possible.

Comprehensive Guide to Metal Stamping Mold Assembly

Introduction

Metal stamping molds are essential in manufacturing industries, enabling precise and efficient production of metal components. The mold assembly process plays a critical role in ensuring the quality, durability, and accuracy of stamped parts.

In this article, we will walk you through the complete metal stamping mold assembly process, covering essential steps, best practices, and quality control measures. Whether you are a mold engineer, manufacturer, or industry professional, this guide will provide valuable insights into achieving high-performance stamping molds.

I. Pre-Assembly Preparation

Before starting the assembly process, it is crucial to prepare the necessary tools, measuring instruments, and reference documents to ensure smooth execution.

1. Tools & Measuring Instruments

Ensure that the required tools and measuring instruments are available, including:

• Hand tools: Wrenches, files, copper hammers
• Surface finishing tools: Oil stones, sandpaper, pneumatic grinders, polishing heads
• Cleaning agents: Mold cleaner
• Adhesives & lubricants: 680 glue
• Measuring instruments: Vernier calipers, micrometers, gauge blocks, thin shims, demagnetizer, etc.

2. Understanding the Mold

Before assembly, review all relevant drawings:

• Product drawings
• Layout drawings
• Mold part drawings

3. Mold Assembly Process Overview

Familiarize yourself with the entire mold assembly process:

1. Main Plate Gluing (Clamping Plate + Stripper Plate + Bottom Plate)
2. Template Assembly
3. Clamping Plate Component Assembly
4. Stripper Plate Assembly
5. Bottom Plate Assembly
6. Upper & Lower Mold Matching & Confirmation
7. Mold Base Gluing (Upper & Lower Mold Base)
8. Installation of Standard Components
9. Trial Stamping & Sample Testing

II. Template & Component Inspection Before Assembly

1. Template Inspection

✅ Material & Hardness Verification: Ensure templates have undergone deep-freezing and stabilization treatment.
✅ Flatness & Warping Check: Warping should not exceed 0.005mm per 100mm.
✅ Hole Position & Processing Accuracy: Verify drilled holes, allowances, and surface finish.
✅ Screw Hole Depth & Alignment: Check threaded hole depth and perpendicularity for proper fastener fitment.
✅ Embossing & Pressing Grooves: Ensure correct width and depth.
✅ Labeling & Marking: Verify mold number, material width, pitch, and part name.

2. Component Inspection

• Material, Quantity & Hardness Verification
• Dimensional Accuracy Check

Proper inspection eliminates potential errors that could cause misalignment, improper fits, and structural weaknesses in the final mold.

III. Template Machining & Finishing

1. Mold Base Preparation

• Clean all threaded holes of debris; check for damaged or unthreaded holes.
• Deburr sharp edges and corners using a flat file.
• Polish the surface with an oil stone to remove burrs.

2. Hole Deburring & Edge Rounding

• Use round oil stones, files, grinders, and sandpaper for chamfering insert holes, round holes, and square holes.
• Remove oxidation residues from wire-cut holes using fiber oil stones and round rods.

3. Surface Finishing

• Polish the template with fine oil stones in the direction of the grinding pattern.
• Use lubricating oil during polishing to prevent scratches.

4. Demagnetization

• Use a demagnetizer to remove magnetism from the mold base and all components to prevent iron powder absorption, which could affect assembly accuracy.

5. Cleaning

• Clean templates thoroughly using mold cleaner and compressed air.
• Precision mold assembly requires a high level of cleanliness to ensure optimal performance.

6. Component Handling

• Engrave part numbers on components.
• Add lead-in angles to guide posts.
• Sort, match, and demagnetize all parts.

Tip: Precision molds require extreme cleanliness to prevent defects in stamped parts.

IV. Measurement & Alignment Verification

1. Template Parallelism Measurement

• Fix a dial indicator to zero on a reference platform and measure.
• Standard tolerance: ≤ 0.002mm.

2. Template Warping & Deformation Check

• Press one end of the template and observe dial indicator changes at the other end.
• Deformation should not exceed 0.003mm.

3. Main Template Parallelism & Warping Measurement

• Tolerance should not exceed 0.005mm.

4. Guide Post & Guide Bushing Measurement

• Ensure guide posts conform to the required dimensions and roundness.
• Measure guide post fitment and machining accuracy per the drawings.

V. Mold Gluing Process

1. Gluing Steps

Step 1:

• Use 0.005mm shims to check for gaps after mold closure.
• The mold is qualified when shims cannot enter the gap.

Step 2:

• After confirming the main template, insert a 10mm positioning pin from the clamping plate to the bottom plate to align the three primary templates.
• If any gaps exist, check for debris or interference before proceeding.

Step 3:

• Clean guide post and guide bushing thoroughly.
• Insert guide posts into the stripper plate and secure with screws.
• Place 0.2mm steel shims in each guide bushing hole.

Step 4:

• Apply 680 glue evenly on the guide bushings while rotating them for even distribution.
• Slowly insert guide bushings into the template until they rest against the steel shims.
• Repeat for all guide bushings.

  VI. Standard Component Assembly

1. Standard Component Inspection

• Verify that all standard parts meet specifications.

2. Height & Position Check

• Confirm the heights of floating pins, equal-height sleeves, limit posts, guide pins, and ejector rods.

3. Standard Component Installation

• Clean all round holes before inserting components.
• Install components into the mold cavity in order.

4. Final Confirmation

• Ensure all parts are flat and properly fitted.
• Verify free movement of standard components.
• Check for clogged scrap ejection holes.
• Ensure adjustment rods are correctly positioned and do not interfere with other templates.

VII. Mold Testing & Issue Documentation

1. Mold Closure Height Verification

• Record closure height in the Mold Testing & Issue Report.

2. Manual Mold Closure Test

• Close the mold manually to check for proper spring compression.

3. Trial Stamping & Sample Testing

• Record initial data for comparison in subsequent trials.
• Repeat trials until samples meet specifications.

4. Issue Analysis & Data Collection

• Document all design & machining issues.
• Analyze the root cause and record corrective actions.
• Collect data for future design optimizations.

Example: Mold Testing & Issue Report

Date Issue Description Corrective Action Design Issue Machining Issue Resolution Date Result Responsible Person 2.18 Tight-fitting D07 forming part Wire-cut rework ✔ 2.18 Normal Engineer A 2.19 S05 part causing ejection failure Added ejector structure ✔ 2.19 Normal Engineer B 2.19 Dimension 2.02mm undersized Added 0.02mm shim ✔ 2.19 Normal Engineer B 2.20 Sent for FAI inspection 2.20 QA Inspector

 Note: All mold trials must be fully documented, ensuring a complete history of deviations and corrective actions.

Conclusion

The metal stamping mold assembly process requires precision, attention to detail, and strict quality control to ensure high-performance and long-lasting molds. By following these structured steps—from pre-assembly preparation to final testing—manufacturers can optimize efficiency, reduce downtime, and improve mold longevity.

Implementing these best practices will help ensure high-quality stamped parts, reducing waste, rework, and production costs.

Looking for High-Quality Metal Stamping Solutions?

At FPIC, we specialize in precision mold manufacturing with a focus on quality, efficiency, and innovation. Contact us today to learn more about our custom mold solutions!

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