Colbalt Lathe tools

[DalboyParticipant @dalboy]

[DalboyParticipant @dalboy]

In my odd bits I have two Cobalt tools steels for the lathe I know about HSS.

Are they good and what metals would they be used on and what type of finish would you expect to get off of them

[VicParticipant @vic]

I have some HSS toolbits that say 5% or 8% cobalt. If this is what you have it’s just one of many grades of HSS that are available.

**LINK**

I recently bought an M42 HSS wood turning gouge as it was supposed to be a lot better in terms of sharpness and longevity of the edge but I can’t see it’s any better so far.

[Russell EberhardtParticipant @russelleberhardt48058]

Those tools are not likely to be cobalt but a grade of HSS that contains cobalt such as M42. A somewhat superior grade of HSS. It has better high temperature performance than the other grades and can work well when red hot.  Not likely to be important in the home workshop!

Russell

Edited By Russell Eberhardt on 14/12/2018 14:48:54

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Vic on 14/12/2018 14:44:00:

I have some HSS toolbits that say 5% or 8% cobalt. If this is what you have it’s just one of many grades of HSS that are available.

**LINK**

.

That's a handy reference document … Thanks, Vic

MichaelG.

[Ady1Participant @ady1]

Cobalt holds its edge better at low speed and is not prone to chipping, very tough in the right circumstances

It's the go-to tool if using a shaper or carving tough material on a lathes backgear, you do far less resharpening than with standard hss

At higher speeds carbide is king, hss isn't even close, even cobalt hss doesn't perform any better than hss once the speed and grinding action ramps up

Each material has its merits

[DalboyParticipant @dalboy]

Thank you all for the information so they are well worth keeping. They are 3/8" square X 3" long.

[Ian S CParticipant @iansc]

HSS wood lathe tools have a great advantage over carbon steel when it comes to sharpening, you don't draw the temper if you get the edge just a little warm. I feel that a well sharpened carbon steel skew chisel, scraper, or gouge cuts better than HSS, but the HSS holds the edge it has longer.

Ian S C

[DalboyParticipant @dalboy]

Posted by Ian S C on 15/12/2018 11:17:44:

HSS wood lathe tools have a great advantage over carbon steel when it comes to sharpening, you don't draw the temper if you get the edge just a little warm. I feel that a well sharpened carbon steel skew chisel, scraper, or gouge cuts better than HSS, but the HSS holds the edge it has longer.

Ian S C

I agree unless you are turning well seasoned Oak

[VicParticipant @vic]

Some may find this of interest.

**LINK**

Carbon steel make good finishing scrapers for woodturning if you can find them.

[Mick B1Participant @mickb1]

My father-in-law gave me 2 pieces of 1/2" square Cobalt HSS in 1975. I ground one of them to a 55 degree screwcutting tool. I have to admit that my use of it has been highly intermittent, but I've only recently reground it for the first time, after doing some 1" x 8 TPI threads about 6" long for locomotive superheater header bolts.

Use it at reasonable cutting speeds, and it could last a lifetime – though I suspect the basic quality of the HSS might be as important as the cobalt…

[egaParticipant @ega]

Posted by Vic on 15/12/2018 18:58:37:

Some may find this of interest.

**LINK**

Carbon steel make good finishing scrapers for woodturning if you can find them.

Thanks for the link. The Eccentric Engineer over on the right is a fan of cast alloy.

Woodturning scrapers were traditionally made from worn out files, of course (use with care!).

[egaParticipant @ega]

Posted by Vic on 15/12/2018 18:58:37:

Some may find this of interest.

**LINK**

 

Carbon steel make good finishing scrapers for woodturning if you can find them.

Thanks for the link. The Eccentric Engineer over on the right is a fan of cast alloy.

Woodturning scrapers were traditionally made from worn out files, of course (use with care!).

PS duplicate post caused by using back button – sorry!

Edited By ega on 16/12/2018 11:01:36

[DalboyParticipant @dalboy]

Posted by ega on 16/12/2018 10:59:58:

Posted by Vic on 15/12/2018 18:58:37:

Some may find this of interest.

**LINK**

 

Carbon steel make good finishing scrapers for woodturning if you can find them.

Thanks for the link. The Eccentric Engineer over on the right is a fan of cast alloy.

Woodturning scrapers were traditionally made from worn out files, of course (use with care!).

Files as scrapers are just to brittle to be used as scrapers unless someone is in the know on how to go through the reheating to make them safe they are best avoided. I know turners of old use to use them but people new to the hobby are always told to avoid them as that is where most accidents happen

Edited By Derek Lane 2 on 16/12/2018 11:47:01

[egaParticipant @ega]

Posted by Derek Lane 2 on 16/12/2018 11:46:29:

Posted by ega on 16/12/2018 10:59:58:

Posted by Vic on 15/12/2018 18:58:37:

Some may find this of interest.

**LINK**

Carbon steel make good finishing scrapers for woodturning if you can find them.

Thanks for the link. The Eccentric Engineer over on the right is a fan of cast alloy.

Woodturning scrapers were traditionally made from worn out files, of course (use with care!).

Files as scrapers are just to brittle to be used as scrapers unless someone is in the know on how to go through the reheating to make them safe they are best avoided. I know turners of old use to use them but people new to the hobby are always told to avoid them as that is where most accidents happen

Edited By Derek Lane 2 on 16/12/2018 11:47:01

As MEs we certainly ought to be capable of applying suitable heat treatment; with or without, it helps if the file concerned is a thick one and the woodturner is not!

[DalboyParticipant @dalboy]

Posted by ega on 16/12/2018 13:03:43:

As MEs we certainly ought to be capable of applying suitable heat treatment; with or without, it helps if the file concerned is a thick one and the woodturner is not!

My answer above was about scrapers in woodturning

Yes but tell a woodturner who is new to the hobby that it is unsafe he or she will not be aware of the problems until informed.

I do a lot of woodturning as can be seen HERE and am fully aware of the problems How many Model Engineers do wood turning that would have the need to make a scraper for that purpose not many I should think.

[clogsParticipant @clogs]

as well as wood turning tools have a few metal files (at least 6) that have been reused as cold chisels ….

u can see where they have been heated and reshaped……..

mine have not chipped and hold a good edge…….these were given to me by some old guy…..who's no longer with us……but I do thik of him when I used said chisels…….

[Author]

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