Machining a diamond tread pattern on a flat surface in aluminum 4

[RyanMeister]

I know this can be done on a cylindrical surface (knurling) but what about a flat surface? I'm aware of the availability of tread plate but my part is substantially thick and the value (and quantity) is not enough to justify casting.

Thanks!

 

[CoryPad]

It is possible to do this with a flat surface. You could use the same roller used to make a cylindrical part as long as you use enough force against the flat piece and use an appropriate backing piece.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[RyanMeister]

Thanks. What I failed to mention is that the surface is at the bottom of a recess. This would mean that only the middle part of the surface could be reached with the roller. Any other ideas?

 

[mncad]

Your subject says machining, what processes (equipment) do you have availble? What size part are we talking?

mncad

 

[RyanMeister]

mncad-
The parts are small: 1" X 2.5" x 4" with a .5 x 1" x 2" recess inside. As for processes, we have only a small shop for prototyping. We outsource our fabricated metal parts.

 

[RyanMeister]

mncad-
I should mention that the pattern need not be "machined" per se.

 

[BillPSU]

One approach is to make a hardened metal stamp with the reverse of the desired pattern and place the stamp in the recess and apply a load on the stamp coining the material below. The back of the part will have to be flat and support by an appropriately strong plate. The strength of the material will determine the tonnage required. The ductility of the material will determine how good the material flows.

The material should be fully annealed to improve the ductility. Tonnage applied should be monitored first to learn what is the correct tonnage but also to avoid driving the stamp through the part. Stripping the part from the stamp may be required.

 

[dvd]

You could EDM that pattern into your plate.

 

[RyanMeister]

Thank you BillPSU and dvd! Good ideas. I'll run with them.

 

[aamoroso]

When I was going to school for mahcining, years ago, we made a small bench vise. There were serations, small diamond shape cuts, on the face of the vice jaws. We did these on a broaching machine with a lathe tool. about .005-.01 deep and sliced across the surface. Little oil and a fast feed.