Best material to make a punch for cutting

[var10]

Hi,

I am trying to make a punch to cut gasket foam material such as the A910 acrylic foam or AGP200. Still not decided on the foam. But thickness is around 1-1.5mm. Instead of sending them out to a supplier to precut the foam, I am planning just to make a cutting punch. Are there any recommendations on what material for the punch I should use. Is tool steel good enough? and if I just have the cutting angle to 60 deg would it cut easier. I already made one with 60deg and tool steel to cut 1.6mm silicone gasket. All that I have to do is tap it with a mallet and the gasket of desired shape is ready. Should I treat the foam gasket in the same way?

Thanks in advance.

 

[ornerynorsk]

Have a look at the heavy duty style of die cutting tools, not steel rule dies. Tool steel is more than good enough. Any good high carbon steel with the proper heat treat is going to make a fabulous punch for what you need.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[tomwalz]

Look for steel rule dies.



Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[ornerynorsk]

I think you are looking for something like this, that can be manually struck with a mallet?

http://www.fremontcuttingdies.com/images/website_110.jpg

Steel rule dies are appropriate for guided, press type cutting, but do not work well manually.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[var10]

Thanks guys. I will look into steel rule dies.

@ornerynorsk - are they also not steel rule dies? The website has few varieties. I think most materials to cut these foam gaskets should be fine. I just need to specify a steep angle, sharpen the tool every so often and use a cutting pad when punching with a mallet?? But don't have to do any of this with steel rule dies, as once they wear out you throw them?

What tolerances can I achieve with a steel rule die? The slots on my foam are 3mm x 12mm wide. Using a 1 mm thick foam.

Thanks

 

[ornerynorsk]

Steel rule dies are the very thin blades set into laser cut slots in dieboard (a type of plywood) and supported by rubber blocking. Yes, they are essentially disposable, but would be good for 100,000+ hits in lightweight foam gasketing material. These dies are not suitable for manual use with a mallet.

The heavy duty dies, also known as dinking dies, are formed from much heavier cross-section steel blade material, and do not require the support of a dieboard or rubber blocking. These are frequently used in diecutting presses, as well, but may be used manually with a mallet. They must be used with a cutting mat. Two advantages of this format are that you may perform stack cutting when used in a press. That is, multiple layers of material may be stacked and cut in one hit, depending on the material of course. The second advantage being that they are re-sharpenable. The cutting edge is generally ground at about a 20 degree angle, as opposed to the 30 degree angle that you mentioned in your original post (30 degree being the compliment to the 60 degree you mentioned).

Steel rule dies are a bit cheaper, in my experience, and the lead time tends to be quicker, but for manual usage, a dinking die is truly your best option. Plenty of material on the web for further reading and research.

Good luck!

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[silveringchap]

Silver steel or D2 tooling steel would be more than good enough