I am ignorant when it comes to metallurgy.
I ordered some extractor rings and magazine springs from Wisner's a few minutes ago. So far so good. I looked at their claw extractors and noted that they are made out of 4142, milled on a CNC center and heat treated. I also looked at the Williams website. Their extractors are made out 0f 4140, milled on a CNC center, tumbled and heat treated.
I support both companies, and since these are not high dollar items, cost is not an issue. Does anyone have any information if either 4140 or 4142 might be better for this application (more durable, better grain structure, whatever)? Please edjumacate this hillbilly. Thanks,

lawndart
(previously known as "get your butt in here you're late for dinner again!")

I believe in 4140 the 40 stands for .4 percent carbon .4142 would be .42 percent carbon. Not any real difference. Hope I am right abd I HOPE THIS HELPS>The 41 is crome moly I think.

Exactly right, the average Carbon content is 2% higher in 4142 ... it is a Chrome Moly Alloy. The average content for 4140 is .40 % and 4142 is .42 %. For this application either is fine. The materials also come in PreHard condition. Both make great racing axles for quads and 3 wheelers.

quote:

Originally posted by machinistbutler:
I believe in 4140 the 40 stands for .4 percent carbon .4142 would be .42 percent carbon. Not any real difference. Hope I am right abd I HOPE THIS HELPS>The 41 is crome moly I think.

Correst sir....for all intents and purposes AISI 4140 and AISI 4142 are identical materials as the tolerances of carbon content overlap by .05

Thank you gents.
I'll order some extractors on Monday.

dart