Ceilidh ... Re^4: New coining results (Answers)

Hydraulic Die Forming Discussion Group

Re^4: New coining results (Answers)

Doug,
I just scrolled down the forum list to find your unanswered question...the answer is the die is a female die that does take considerably more pressure to coin the metal, a male die would take little pressure but would be an order of magnitude more difficult to machine. One method it to create the female die first, heat-treat and temper, and then strike it into a second piece of tool steel that is hot. You would still have to clean it up but for some designs it'll work easier than maching.
Let me know if you make any dies this way, I would like to see your results.
Phil

On Fri Nov 8, Doug R wrote
--------------------------
>Phil,

>Another question....

>From the picture I can't tell whether your die is male or female. To clarify my question, a male die would be similiar to metal stamping dies for putting numbers on workpieces. For a male die you'd have to machine away the background leaving a raised pattern. The male die would impress the pattern into the workpiece.

>A female die would have a sunken pattern milled into it. The workpiece material would have to extrude into the die.

>Which did you use? My experience tells me a male die would require considerably less tonnage then a female die. But the male die would also be considerably more complicated to mill.

>If my thinking is correct here there may be hope for us tonnage limited folks yet by using male dies.

>thanks,

>Doug
>
>
>
>
>
>
>
>
>On Thu Nov 7, Phil Poirier wrote
>--------------------------------
>>In answer to all the previous questions....
>>I drew the simple curve pattern using Rhino, polar arrayed the pattern 60 or 70 times to create the spirograph effect. Sent that file to my CNC mill and cut the pattern with a .020" ball endmill. Wrapped the piece in stainless foil, heat treated to 1525 F, air cooled, tempered at 350 F for a Rockwell hardness of at least 60.
>>I used all 150 tons on this design, a 20 ton press can coin about 5/8" diameter, and a 50 ton press can coin about a 1" diameter.
>>Ciao,
>>Phil

>>On Thu Nov 7, Doug R wrote
>>--------------------------
>>>Phil,

>>>Does your press have any sort of gauge indicating the tonnage being used? I'd like to try something on this order, but am tonnage challenged so I'm curious how much force was required.

>>>Also, is your die heat treated?

>>>thanks,

>>>Doug

>>>On Wed Nov 6, Phil Poirier wrote
>>>--------------------------------
>>>>Here are photos of recent 150 ton coining trials, the top image shows the die with the coined sterling. The lines in the sterling are .025" wide X .017" in depth and about 1.75" in diameter. The bottom shows the piece after doming and assembling into a box. Die was made with A2 steel.
>>>>I hope you enjoy. Does anyone else use the press for coing or have any coining images to share?
>>>>Phil
>>
>

Mon Nov 18