recommend good quality lathe chuck key

[gav0994]

Can anyone recommend me a good quality chuck key?

I require a 1/4" key for my pratt burnerd 4 jaw on the boxford. It didn't come with one and the one I purchased from myford looked and seemed good quality.

Unfortunately after one session of "4 jaw fun" Doubleboost style has resulted in a chuck key that is already twisting at the end.

 

[ford34/2]

your supposed to harden it, and then temper it--

Stan

 

[gav0994]

your supposed to harden it, and then temper it--

Stan

Don't have the equipment for that. Also I would expect a ready made one to be hardened and tempered.

Yes, I know myford is now owned by RDG tools and most of the stuff is Chinese mass produced stuff, but I bought the higher priced one, extended shaft as it looked a far higher quality than the RDG versions.

 

[brightspark]

Don't have the equipment for that. Also I would expect a ready made one to be hardened and tempered.

Yes, I know myford is now owned by RDG tools and most of the stuff is Chinese mass produced stuff, but I bought the higher priced one, extended shaft as it looked a far higher quality than the RDG versions.

ring them up and complain if its soft as sh...te

 

[MattH]

I've made my last three out of stainless and they aren't hardened. I use one on my 12" four jaw without problems.

 

[doubleboost]

You can make one from a decent sized cap head bolt
Carefully grind on the square (don't let it get hot)
Weld a "T" handle on to it
The material is already a the correct temper

 

[brightspark]

You can make one from a decent sized cap head bolt
Carefully grind on the square (don't let it get hot)
Weld a "T" handle on to it
The material is already a the correct temper

now that u mention it i made mine for the 4 jaw out of an old high tensile bolt ground up years ago

 

[addjunkie]

I used to use a ratchet wrench, with a short extension, ground to fit, lasted the 10 years i had that lathe.

 

[ford34/2]

Unfortunately after one session of "4 jaw fun" Doubleboost style has resulted in a chuck key that is already twisting at the end.

send it back and play *ell-- no excuse for it to be soft.

Stan

 

[Digger6135]

Lathe chuck keys have specific dimensions, if you use excessive leverage it is possible to damage the jaws in a three jaw chuck.

Digger6135

 

[gav0994]

send it back and play *ell-- no excuse for it to be soft.

Stan

I reckon I can re purpose the main body of it and replace the business end - possibly with an old 1/4 HSS lathe tool I have lying in a drawer. Not too sure if this would work?

 

[Pete.]

I reckon I can re purpose the main body of it and replace the business end - possibly with an old 1/4 HSS lathe tool I have lying in a drawer. Not too sure if this would work?

It won't work. HSS is hard but not tough. Cut one from a 12.9 bolt and it'll be far better suited to the task.

 

[Agroshield]

You're supposed to harden it, and then temper it

I've never understood the logic of this. A hardened key will cause more wear to the chuck pinion. What would you rather replace when it's worn out - a simple straight piece of rod with a square filed on the end or a complex square-threaded, shouldered item with an internal square hole? Use a decent bit of steel in the first place (e.g. grade 8.8 bolt), unhardened, and it will outlast you.

 

[ford34/2]

A chuck key can be subject to high stresses and repeated use means wear. Then there is the handle which if made of low grade stuff will bend like a pretzel

1018 deep carburized and heat treated to Rc 50-55 would work pretty well but a deeper hardening steel like oil or water hadening drill rod or some other high carbon steel would be better. There are proprietary case hardening (Kasenite, Hardn'Tough, etc) compounds that would enhance wear but have litttle penetration. In a chuck wrench you need deep strength because of the concentrated stresses. Consider where the square enters the chuck screw. A shallow case will fail because the underlying softer material yields and the square will ductile fail in tortion if not twist off.

http://kittstools.securesites.net/store/lathe_chuck_keys.html

You may well remember the cheap drill chuck keys supplied with many of the 1/2" drills years ago, if you were unlucky to use the machine on a very regular basis you will know the mild steel keys didnt even last a few weeks, all the leading Brand name chuck suppliers I know harden their keys, maybe they know the reason why.
Stan

 

[graffian]

I keep meaning to make one, for my cam lock pins. I got my nephew to save a broken coil spring to make it from.
I am using a shattered jap torx bit, ground to a square and used in a ratchet, it works well. Well far better than the
nasty soft bent thing that came with it[the square is more like an octagon].