304 CRES Stainless Steel

[Glenn Norris]

What does CRES stand for and is there Different Grades for this material? How well does it machine?

[Matt@RFR]

CRES stands for Corrosion Resistant. What you have is regular old 304.

[Glenn Norris]

Thank you for that info. This is very helpful.

[davereagan]

It machines ok, but much slower than 1018. Drilling with split point cobalt at 30 sfm is what I would recommend. Milling with cobalt roughers flooded (65 sfm) and TiALN coated carbide finishers dry (250sfm). Rubbing work hardens the piece. Never dwell and you should be good.

[mfgbydesign]

If you can, use 304L; it has higher machinability. If no further specs are called out (ASTM, etc.) any commercial grade can be used. 304 is Austenitic (non-magnetic). End milling & turning speeds are 60-110 SFPM HSS, 220-360 SFPM carbide (from the Machining Data Handbook). It work-hardens easily so don't dwell or make skin passes. It welds easily also.

[RomanLini]

Great info, thanks all.

How does 303 compare to 304 for lathe machining, assuming that both are readily available?

[JimBoyce]

303 is 2 to 5 times EASIER to machine. Given a choice I think any experienced machinist would go with 303.

[ImanCarrot]

An old saying: "303 she's for me, 304 she's a whore"

[tbooker]

I have a material call out that only says "CRES per Matl Spec 6863". Anyone know what that spec is? Would that make the CRES 301, 303, 304?
Thanks, Tim

[SirDenisNayland]

But 304 looks so lovely when done right