Metal Stamping Material + Metal Finishing Selection Guide

Choosing an appropriate material for a progressive stamping project is about finding the right balance between part performance, manufacturability, and cost (of parts and the assemblies they go into). There may be multiple suitable options for an application, so it’s important to consider all of the material properties and design requirements before making a final decision.

At CEP Technologies Corp. we specialize in small to medium sized progressive stampings for the electronics, automotive, aerospace, power protection and other industries. Our team of engineers, designers, and expert stampers provides end-to-end stamping services including prototyping, computer modeling, tool and die building, stamping, metal finishing processes, and packaging.

Learn more about material selection, common metals used in progressive stamping, and different types of finishes for metal stampings.

How To Select the Right Material for Metal Stampings

At CEP we provide custom progressive stamping for miniature to small parts. We stamp metal coil materials between 0.002 in. and 0.080 in. thick and blanks up to 6×6 in. square. Our high speed presses range from 15 to 60 tons, and can supply customers with medium to high annual volumes of 25,000 to 1,000,000 parts. We also provide in-house tool and die building and maintenance for the lifetime of each project.

When selecting material for stamped parts and components, consider these factors:

Cost: Material costs vary based on supply chain availability, relative rareness, and form of the raw material. Prices for precious metals like copper or gold may be higher if an entire part is stamped from them compared to thinner electroplated or selectively plated coatings. Different types of steel are often cost-effective; although, alloys may be more expensive.
Part end-use: How and where a part will be used is a major factor in material selection. Consider things like exposure to moisture, extreme or fluctuating temperatures, dynamic physical forces, and other things that contribute to wear and tear. Also consider if high mechanical or tensile strength, electrical or thermal conductivity, solderability, weight, or other properties are important to the specific application.
Formability: Depending on the geometry of the part, it may be easier or more difficult to bend, shear, pierce, or perform other operations on. This is especially true when tolerances are tight. Consider how each material’s bendability, modulus of elasticity, springback, brittleness, and hardness affect the stamping process.
Corrosion resistance and protection: Parts that are exposed to corrosive environments such as rain, salt spray, high humidity, or harsh chemicals need extra protection to ensure a long service life. Some materials, such as stainless steel, are inherently resistant to corrosion, while others may require a protective coating like zinc or tin.
Surface hardness: Is important in stamping because it determines the amount of force required to cut or deform the material. Higher carbon content material is generally harder and more brittle, which may affect manufacturability.

Material Selection Guide

The best material for a given application depends on the specific end use, stamping operations used, and anticipated environmental conditions. The following are common materials used in progressive stamping:

Stainless Steel: This alloy of steel and chromium has high corrosion resistance, excellent strength, and temperature resistance. It is available in several grades including some that are biocompatible for medical applications.
Aluminum: This is a soft metal with excellent formability and conductivity. It is also lightweight, highly recyclable, resists corrosion and remains stable in low temperatures.
Steel: Steel is a ferrous (i.e., iron based) metal available in several forms including hot or cold rolled steel, low, medium, or high carbon steel, and various high-performance alloys. Steel is highly formable, durable, and cost-effective. Many steels are not corrosion resistant and may require additional plating or coating. Higher carbon levels contribute hardness and brittleness and lower solderability, which may impact manufacturability or part performance and durability.
Pre-galvanized steel: A zinc coating on the surface of steel improves corrosion resistance and reduces post-stamping metal finishing processes required.
Nickel-plated steel: This is a pre-plated material with higher corrosion resistance than zinc coatings or plating. It reduces post-stamping finishing needs.
Brass: A strong, durable, and highly conductive alloy of copper and zinc with good ductility, corrosion resistance, and antimicrobial properties.
Phosphor bronze: An alloy of copper, tin, and phosphorous that is elastic and malleable, highly conductive, and very resistant to corrosion and wear.
Beryllium copper: A copper alloy often used for high strength, high stress applications. It has high conductivity, is malleable and easy to form, and can be strengthened with heat treatment.
Precious metals: These include gold, silver, and platinum. They are generally softer metals that are highly malleable and conductive for electrical or medical applications. Precious metals are often expensive and it may be more cost-effective to use these materials for selective plating processes instead of stamping entire parts from them.

Types Of Metal Finishings

Various types of finishes for metal stamped parts help protect the base metal from corrosion, enhance conductivity, or improve solderability and other part characteristics. Some common metal finishing processes include:

Cleaning: Stamped parts often require cleaning to remove grease and oils. For some applications high precision cleaning is required to remove particles and contaminants. This technical cleaning can be done with various methods and solutions including bubbling water baths or vibrating baskets in cleaning solution. It is possible to achieve different cleanliness and particle size tolerances.
Heat treating: Heat treatment is often applied to transporting parts through an oven or industrial furnace. The high heat alters the metal’s grain structure to enhance hardness, smoothness, and other characteristics.
Plating: Adding a protective outer layer of metal can be done before or after the stamping process and improves corrosion resistance, conductivity, or other properties. Common plating materials include nickel, copper, tin, zinc, and precious metals. Learn more about plating here.
- Electroplating: An anode (i.e., a piece of the plating material) and cathode (i.e., the stamped part to be plated) are placed in an electrolyte bath with an electric current, which deposits a thin layer of metal ions on the part. An electric current deposits a thin layer of metal onto the base metal surface.
- Barrel/immersion plating: Stamped parts are placed in a bath of metal ion solution, resulting in a thin metal coating without the use of electrical current.
- Reel to reel plating: Finished parts are attached to a reel-to-reel carrier system that feeds into the plating bath and then taken up onto a second reel. Parts are secured to webbing that exposes the area to be plated and the plated strip is interleaved with a paper strip to keep the parts separated. This process can also be used to pre-plate raw material blanks that will later be stamped.
- Selective plating: Commonly used with precious metal plating, this method uses special masking material to block off areas of a part that will not be plated.
Deburring, sanding and grinding: These methods use abrasives such as sandpaper or a grinding wheel tool to remove burrs or imperfections, smooth rough edges, and prepare the metal for further treatment.

Quality Progressive Stamping and Metal Finishes for Stamped Parts by CEP

At CEP we are committed to providing highest quality, comprehensive stamping services and rapid prototyping to customers around the world. With facilities in New York, Texas, and China we have an efficient, global reach. to our customers. We are IATF 16949:2016 and ISO 14001:2015 certified with TUV Rheinland of North America.