Hss blanks

[marcros]

If I buy hss blanks from chronos, to make some woodturning tools from, is it going to be pre-hardened and so just need grinding?

I want to make a couple of miniature scrapers but have no source of scrap material, and to be honest if i have to harden and temper steel, I may as well go and buy the tools from mr iles. At least that way I wi get hss rather than o1.

 

[CHJ]

Any HSS Blanks you buy from a tool supplier will already be heat treated and fit for purpose (cutting)

Heat treatment of such steels is not realistically possible without quite elaborate furnaces and atmospheric control and timing.
The only time I've been involved with treating such steels was with a Vacuum and Argon atmosphere computer controlled furnaces.
Even the quenching process within the vacuum furnace was controlled for temperature in the internal oil bath and subsequent completion of cooling in Argon for some components.

 

[marcros]

Thanks chas.

 

[n0legs]

Any HSS Blanks you buy from a tool supplier will already be heat treated and fit for purpose (cutting)

Heat treatment of such steels is not realistically possible without quite elaborate furnaces and atmospheric control and timing.
The only time I've been involved with treating such steels was with a Vacuum and Argon atmosphere computer controlled furnaces.

So do you lose any of it's properties when cutting and working the hss into what you need to make?
Are there any methods to working with it, watching out for heat build up etc,?

 

[CHJ]

....
So do you lose any of it's properties when cutting and working the hss into what you need to make?
Are there any methods to working with it, watching out for heat build up etc,?

Ground with common sense HHS should be fine, it will stay viable as a cutting steel up to or near red heat, whatever you do, do not quench anything with a fine edge in water to cool it, let it air cool.
If you have thin sections near a cutting edge you can induce micro shock fractures along the edge.

Water cooling if the blank is only just above comfortable hand heat is OK but the very sharp edge may be hotter so don't be too quick to drop it in the water.

Straw colour or minor Bluing is acceptable as long as you don't quench, better to not make a habit of it though.

HSS cutting mild steel on a metal lathe will happily produce blued chippings as long as the tool can disperse the reciprocal cutting heat into the tool shank.

 

[n0legs]

Thanks Chas, much appreciated

 

[chipmunk]

This thread might be of interest... https://www.ukworkshop.co.uk/forums/making-hollowing-tools-t81753.html

Jon

 

[Phil Pascoe]

Interesting thread. I haven't followed it up yet, as I've less space than I'd like after moving and losing £40,000 on my house.

 

[chipmunk]

I just realized that I haven't posted my small box scrapers made from 1/4" toolbits...

The one on the left is 1/4" x 4" round toolbit extended by epoxying/locktiting it into a length of 8mm steel rod bored in the end and then the whole lot epoxied into a handle.

The second is set-screwed into a 65mm M16 bolt, bored out to take the square toolbit.

The third was epoxied between two boxwood vee-shaped sections, turned round holding the square toolbit in the chuck and then the whole lot was mounted into a close-fitting hole bored into the end of a handle.

I hope this gives you some ideas.

(The square section toolbits are relieved down the left hand edges as advocated by Chris Stott)
Jon

 

[graduate_owner]

I'm going to make some of these.

K