SS 304 Balls

[Arbutus]

Hi - I purchased a bag of 10, 1" Stainless steel 304 balls which I intend to use for various handles and knobs on some machines.

The (Amazon) product info says Hardness HRC <25 which is a bit odd because SS 304 should be harder than that.

Since these will be drilled and tapped, soft is good. My question though, is the hardening process (available to home machinists) for this material. I have a heat treating oven on the way, good for about 1750F with long programmable soak ramps which should cover all the options.

I am very familiar with heat treatment and hardening of tool steels, but no useful experience with SS. Normally I would consider case-hardening (carburising) because SS 304 is austenitic but again I have no experience with this.

Any thoughts on how to surface or body harden these balls to a consistent quality around RC 50-55 ??

Don Gibson

 

[PeterT]

I'm no expert on this but I didn't think 304 had insufficient carbon for through-hardening. This seems to concur

Hardening 304 & 316 stainless steel (Austenitic)

Hardening 304 & 316 stainless steel (Austenitic). 304 SS cutters, 316 SST pen nibs

www.finishing.com

 

[PeterT]

Says annealed is about 170 BHN. My beta version Excel hardness converter shows (I think) corresponding Rockwell numbers, so that might be an issue too. I usually struggle with references that are incomplete, there are so many scales.

Annealed 304 Stainless Steel :: MakeItFrom.com

www.makeitfrom.com

according to this, various hardness states are offerred

AISI 304 (S30400) Stainless Steel :: MakeItFrom.com

www.makeitfrom.com

 

[Arbutus]

Yeah its messy. I think I'll just bake them to 1400 then bathe in CherryRed(tm) as usual. Not a critical application in this case. I bought the SS 304 because unhardened balls are not available (that I can find) and these need to be drilled and tapped M4. I really did not want to get into grinding off a casing before drilling.

That said - if anyone has a source for unhardened steel balls 1/2" to 2" I would love to hear from you!

https://www.makeitfrom.com/ <--- interesting link! Thanks!

Don Gibson

 

[PeterT]

Mcmaster if you have ordering superpowers or know someone who does
case hardened, might save you some work if you can drill through the skin

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

saves the whole drill/tap operation unless you reeeeeeally want surface hardened

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

I'm sure I've seen metric variants of annealed state (metric) balls on AliExpress or similar

 

[Arbutus]

McM predrilled machine handle balls! Nice. I will be ordering those!

 

[Susquatch]

McM predrilled machine handle balls! Nice. I will be ordering those!

I could swear I remember seeing different size ball handles at Busy Bee in London last time I stopped in there - about 6 years ago.

They are also available on Ali.

 

[Darren]

JW Winco Standard Parts | Home

Manufacturer and Distributor of Standard Machine Parts. Your Partner for Standard Machine Components and Assembly Hardware for Industry.

www.jwwinco.com

has a great selection of knobs and handles and are great to deal with.