View Full Version : Need a new Lathe Chuck Wrench--Recommended Steel?

07-05-2009, 10:53 AM
The previous lathe chuck wrench that I made was about 10" long and it was perfect for not only the various chucks but it would work nicely on the cam locks on the headstock without banging into the headstock. The one that came with the lathe was just too short. Unfortunately I made it out of 1018 (lesson learned) and it has now gone Tango Uniform.

Recommendations for tougher steel? 4130? 1144?

In advance, thanks for the assistance.

07-05-2009, 11:03 AM
either one will work. If you can get the 4130 as heat treated go with that if not the 1144. If you got a piece of hydraulic cylinder rod you could make it out of that and have to buy anything. They're usually 1145.

07-05-2009, 11:03 AM
I've made spindle and chuck wrenches out of Stressproof, with good results. Some of them get used often, others not so much. I do go for a tight slip fit in the holes.

07-05-2009, 11:16 AM
As you are making one from scratch, and irrespective of the material, I'd suggest getting a light compression spring and make part of the spindle to suit the spring. The spring should be a "wind-on" fit and extend past the "square" for the chuck. That way you will have to compress the spring to get the key square into the chuck holes. Similarly, as soon as you release pressure the spring will withdraw the square on the key from the hole.

It will be all but impossible to leave the key in the chuck and so avoid the "drama" of starting the spindle with the key still in the chuck.

If I have time in the morning - and if I remember it - I will take and post a pic or two.

07-05-2009, 12:00 PM
4140 B-7 would my first choice,unless you can heat treat.If you can,then A-2 makes a fine chuck key if hardened and drawn to 48-50Rc.

No offense to Tiffe,but I hate saftey chuck keys,I spend more time picking them up off the floor than actually using them.That and I figure if I can't remember to take the key out of the chuck,I probably don't need to be running the lathe in the firstplace:)

07-05-2009, 12:43 PM
I made my last two from 304 stainless (because I had it). Seems to be working fine, and they lool pretty;)

07-05-2009, 12:52 PM
Last one I made was out of 12L14. After about a year the square end has a nice twist to it but it works fine.

07-05-2009, 01:01 PM
I also made a nice (??) one form a piece of shiny (LOL)0-12 Material. Well it went the way of mush. I was thinking of heat treating it but? Perhaps the 4130 material and flame harden is good.

Shuswap Pat
07-05-2009, 01:07 PM
The other oprion is to make it from a Grade 8 or B7 bolt. It is already heat treated.


Mike Burdick
07-05-2009, 01:16 PM

A material suggestion...

I make both the handle and stem from Grade 5 bolts and they stand up very well without any additional treatment. Grade 5 bolts can be cut using HSS tooling but Grade 8 bolt cut better with carbide.

These are made using a 1-inch diameter bolt with the head turned off. The "threaded" part is turned down such that the four sided key can be cut to the proper size. The handle is a 1/2-inch Grade 5 (or 8) bolt with both the head and threads removed. Of course, larger diameters can be used if one's needs require it. To keep the handle in place I upset the center of the handle with a couple of "grooves" made by a cold chisel before assemble.


07-05-2009, 02:25 PM
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but I hate saftey chuck keys,I spend more time picking them up off the floor than actually using them.That and I figure if I can't remember to take the key out of the chuck,I probably don't need to be running the lathe in the firstplace:)

Yep, I'm with weird' on this. Hate the safety chuck keys.

07-05-2009, 02:58 PM
I have used 1018 and Casenite treated the wrench head. 5 Years use and it is fine.

07-05-2009, 03:14 PM
I made an extension for mine from a cut-down VW Transporter toolkit wheelnut spanner:D

07-05-2009, 03:40 PM
I've found that the square end of a regular socket extension works perfectly for many of my chucks as well as D1-4 camlock pins. Available for less than the cost of the steel alone in just about any handy length. Easily fitted with either a T-handle or a ratchet to speed opening and closing a chuck.

07-05-2009, 11:08 PM
I've got one at work that is a piece of HSS square steel brazed into a piece of 4140 steel tubing. (Crimp the tubing around the square and then braze to keep the square from sliding in/out) Works great and it's light!

07-06-2009, 09:05 PM
Gentlemen--thank you all for taking the time to respond and provide your expertise and experience, it is greatly appreciated. As usually, I have benefited greatly and learned a few things I didn't realize about steel I have laying around. I believe I'll go the 4130 route and take the time to harden it.

Again, many thanks for the assistance.