Micro stamping, CNC punching & Electroforming: a detailed comparison

As products become smaller and smaller, tolerances tighten as well. For you as an engineer, this brings new challenges in designing and manufacturing high precision metal components. Especially for those who are not involved in metal fabrication on a daily base, the various technologies (and jargon!) can be highly confusing - and sometimes even frustrating.

In today's world, there are many opportunities to create high precision metal parts that enable your company to innovative. The technology that suits your solution best, strongly depends on many factors such as industry, material, hardness, volume, complexity, flexibility, lead time, budget and many more.

This blog aims to take away some of the confusion by explaining and comparing Micro Stamping, CNC Punching and Electroforming.

The difference between Micro Stamping and CNC Punching

Let's start by explaining the difference between Micro Stamping and CNC Punching. There are various ways to fabricate metal parts from sheets of material.

As the title above may already suggest, the meaning of the two words might seem the same but really aren't. Stamping and CNC punching are mechanical processes that cut the desired parts from metal using hardened steel tools, but they are in fact used for different purposes and even require different types of machinery.

What is CNC Punching?

Computer numerically controlled (CNC) punching is a manufacturing process. Its efficiency lies mainly in low quantities due to the multiple hits and automated tool changes required to create the part and is therefore highly effective for prototyping.

However, this does mean you might need more than one die to create a final metal part. The costs of one die generally lies between $100 – $1,000. Generally, dies can be created in a matter of days to weeks.

What is Micro Stamping?

With stamping, the part is created in a single strike of the die, as the hardened steel dies are the exact shape of the part. Stamping can also be applied subsequent to of other metal processes such as punching. The ending process of punching can give the metal piece a specific shape.

Its efficiency lies in mass production quantities, but the die costs can run between $5000 – $30,000, depending on complexity. There is also a long lead time to take into consideration with stamping, as a single die can take up to months to build.

The difference between CNC Punching and Micro Stamping

Reading this, the difference between punching and stamping hopefully becomes clear. With CNC punching, specific features of a part are punched out (useful for prototyping) while sheet metal stamping is applied to stamp out one entire metal part (useful for mass production).

Electroforming: create high precision metal parts

Now the differences between CNC Punching and Stamping are clear, we will take a look at Electroforming. Electroforming is a form of additive manufacturing, where metal parts can be build (grown) atom by atom. Just like Chemical Etching, it is a chemical process (Also read a detailed comparison between Chemical Etching and Electroforming).

To produce metal parts, electroforming can use a photoresist to create a deposition pattern on a conductive substrate. Its high repeatability and the ability to produce large volumes make electroforming a highly innovative technology.

Micro Stamping vs Electroforming: which one to choose (and when)?

Due to the fact that the efficiency of CNC Punching is limited to low quantities and prototyping, I will mainly concentrate on the comparison between Micro Stamping and Electroforming.

Which factors should be taken into consideration when choosing the technology that meets your future product requirements best? This table answers those questions.