Lathe chuck keys

[Welderpaul]

What are standard chuck key sizes? Need one to fit a 15mm ish female square drive. Doesnt seem standard, either in metric or imperial equivalent?

 

[madkayaker]

Mole grips? There is multi keys available but might not be big enough for your stuff

 

[rtbcomp]

Get some square key steel and make one.

http://www.cromwell.co.uk/index.php?q=0&p=browse&c=160203&ss=key%2Bsteel

 

[Hitch]

Just make one from a bit of round...or square.... this for the positioner? You dont need to do it up very tight tbh do you?

 

[Welderpaul]

Yeah, bit of 16mm sq bar, but they are peanuts on ebay, well, the ones that are listed are, might just have to whittle down a bit and weld a handle on.
Beats a butchered allen key.

 

[Hitch]

Spring loaded one would be a good bet too i suppose.

 

[madkayaker]

Sorry I was thinking of drill chuck not lathe chuck. Bent bit of square is what we use at work doesn't have to be that tight a fit

 

[gavuk]

Sorry to hi-jack Pauls thread ,but if anyone has a 3/8 hex chuck key ,I'm after a proper key for my 4 jaw chuck.....

 

[Welderpaul]

There are some 3/8 keys are on ebay

 

[gavuk]

Just re-looking now,sure they were hex Paul?

 

[Welderpaul]

Err.

 

[gavuk]

Serves me right for hi-jacking

 

[stormin]

I'm sure 9/16" is a standard size. That shouldn't be too slack in a 15mm square hole. I think most lathe chuck keys are a fairly loose fit so they fall out easily rather than build up speed before flying out.

I may have one I aquired that's too big for my chucks.

 

[Shox Dr]

3/8 drive fits.

 

[Wallace]

RDG Tools keep a range of sizes, I was looking recently for one to fit a 4 jaw independant but it's an odd size so I might as well make one. Chuck keys are usually heat treated for strength and wear resitance.

Link to RDG Chuck Keys

 

[rtbcomp]

....... Chuck keys are usually heat treated for strength and wear resitance.

I was wondering about that, is key steel a heat-treatable metal?

 

[Shox Dr]

I was wondering about that, is key steel a heat-treatable metal?

yes

 

[Pete.]

I don't think it is all hardenable. I have a pile of 10mm keys that are soft as butter.

 

[Wallace]

Memory tells me EN6 for key steel, I think the length of 6mm I bought recently was EN8.

Mike

 

[Shox Dr]

I thought it was. Guess it is but not the best stuff to treating.

Taken from West Yorkshire Steel web site


Heat Treatment
As a bright drawn steel bar it is uncommon to harden key steel. In its supply condition key steel has an approximate tensile strength of 500 to 700N/mm2.

If heat treatment is a requirement, key steel can be heat treated by conventional methods and flame or induction hardening. Please consult your heat treatment provider for full guidance on heat treatment of key steel.