Plastics in hydraulic system as dies

I am worried about plastics that I have acquired/ used as silhouette dies/ positive dies under a hydraulic system. How to differentiate the plastic types. Concerned about those that might shatter over time. Usually I place in a containment system, but sometimes I work in the open without containment

Continuing the discussion from Plastics in hydraulic system as dies:


Does anyone have a preferred class of plastics they use with the hydraulic press. I heard Kevlar is a sound material for use in the hydraulic press. Has anyone had a plastic I.e polystyrene, acrylic et. Al. Shatter in a hydraulic press?

I use 6 mm (1/4 inch) polycarbonate (Lexan is the most common brand name). Very tough stuff. It is available from window glass retailers. If you check online there are claims that 1/2 inch Lexan is bulletproof.

I would not use polystyrene. It breaks easily.

Neil A

Thanks for the advice

Just bought two pieces of 1/2" cast polycarbonate from Amazon. Cut out a 1" equilateral triangle using my jeweler’s saw and #4 blade. Cleaned up with a #2 file chamfering the lead edge and ground th die to a 2" circle with a belt grinder. Put a 2" 95 D urethane disc into a 2" Id piece of pipe with a base welded on the bottom, then a 2" annealed disc of 22 gauge copper, then the die. The pipe is deep enough to contain the urethane, copper disc and partially contain the die so that there enough of the die exposed to be pushed by the press. Pressed up to 2,000 PSI in the hydraulic press and got a nice puffed out triangle. Seems to work just fine…Rob

thats a nice thought to contain your slhouette die…thxs

Look at Susan Kingsleys book on Hydraulic Presses. Not sure of the title, but it is in the archives.

Hydraulic Die Forming for Jewelers and Metalsmiths by Susan Kingsley…time for a re-read…eh? Ciao