416 Stainless Steel

[Dtuck]

I've read that pre-hardened 416 is one of the most free machining SS's and I've had good success with a product I have produced. How does it compare to 420 in injection and comprssion molding?

 

[TVP]

Type 416 will not polish as well as Type 420. It has poor corrosion resistance as well.

 

[mcguire]

420 has 0.15% min carbon while 416 has 0.15% max carbon. So,416 will not be able to reach the same hardness levels that 420 can and will suffer as a mold material for that reason.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[Dtuck]

What about 350 degrees F or less? Does anyone have any experience in this area of temperature. What kinds of corrosion can occur? I have components in for over 18 months without problems.

 

[EdStainless]

The reason that 416 is free machining is the MnS stringers in the structure allow for chip breakage. The same stringers limt the quality of the surface finish.
If you have been using 420 at low hardness, then it might work out.

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[Dtuck]

Your information has been quite helpful. Maybe 420 at lower hardness could be able to get tolerances to 0.0002" like I get with the 416. The 416 is able to make a 64 finish but it's hard to go better. Thanks.

 

[mcguire]

Be careful of dimensional instability due to retained austenite which can come from higher carbon levels. Subzero cooling may be in order. What does everyone else think?

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/