Machining HSS blanks??

[Bruce Caulley]

Ahoy!

 

I don't at the moment have a tool and cutter grinder, but occasionally get a job where a special tool is needed for 1 off use.

 

I have machined silver steel and then flame hardened and tempered followed by a hand finish/sharpen and this has seen me through the simpler jobs in not so hard materials.

 

BUT:

 

Another one has popped up that is in a harder material than a silver steel tool may like, so was wondering if anyone had machined HSS blanks before?

 

I might try it on the weekend and see how I go. Tool is sort of a broach so I will be milling it. I know I can send it out to be made, but the qty on the job doesn't really justify it. Also I know that another shop quoting it already has some of this equipment so can't load up the quote with tooling.

 

I was thinking of using a Tialn endmill with small corner rads, say 16mm with R0.5 and going flat out 8000RPM (wish I had more) with 0.02mm step down using surface finish contour.

 

thoughts?

 

Bruce

[35K chipper]

Bruce,

i've made many from O1, A2, D2, and S7 hardened, tempered then ground. good luck.

 

35k

[DavidB]

I've machined 63Rc before the best way I found was full depth with 5% stepover and upmill don't climb. Use air and vegteable oil in a spray bottle if your machine does not have oil mist.

 

Dave

[Hardmill]

I agree with the full depth and step over

but you should really climb cut and only use

air since a spray bottle will introduce too

much fluid to the tool. JM2C

 

 

PEACE

[DavidB]

Hardmill I have found a much straighter edge by upmilling hard steel.

 

Also use a 6 flute endmill not 4.

 

JM2 cents

[88Matt]

Bruce do you have access to a wire?