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Copper Alloy Comparisons

Posted: Fri Jan 18, 2019 5:05 pm
by BussPrecisionMold
Copper Alloy Recommendation

Objective: Moldstar 90 VS. Ampco 944

Does anyone have any real world comments in regard to one alloy working better than the other in certain situations? The application is a cavity sub-insert in hardened S-7 steel to be used for thermal conductivity to help some thick sections of the part set up. There are going to be some sharp corners at the lamination, and some small round shut-offs of Ø.030 posts. They will also ejector pin holes and waterlines within the inserts.

The material makeup, thermal performance and hardness numbers look like they are the same, we have used both before and could not see any difference, however they were never in side by side comparisons.

The one is about 20% more, the difference between a $20K and $16K in material cost.

Any comments in regard to this would be appreciated to help us make the decision.

Jonathan Buss

Re: Copper Alloy Comparisons

Posted: Mon Jan 21, 2019 1:50 pm
by industrial
We have found Ampco 944 to be more brittle and prone to chipping at eject pins and sharp edges. The Moldstar is also easier to machine.