new chuck key

[tony bastickParticipant @tonybastick78554]

[tony bastickParticipant @tonybastick78554]

Hi all, im making a new lathe chuck key from silver steel, im ok with the hardening but would welcome advice on the temperature that it should be tempered at. Thanks Tony

[Sub MandrelParticipant @submandrel]

Hi Tony,

As it's going to be subject to a lot of torque and will be dropped regularly(!) and it doesn't need any cutting attributes, I'd take it right down to blue.

Neil

[Gary WoodingParticipant @garywooding25363]

I've just made one, but I used ordinary mild steel and case hardened the business end, which is now glass hard. Cheaper than silver steel too.

Gary

[mark mcParticipant @markmc72333]

I made one awhile back for my four jaw chuck so i could move two jaws at a time, never hardened it at all, just mild steel, works grand. Should i have hardened it?

Edited By mark mc on 16/04/2013 16:03:24

[JoParticipant @jo]

I have made numerous for mine out of mild steel and never hardened any. I would prefer to bend the key rather than the chuck.

Jo

[Michael GilliganParticipant @michaelgilligan61133]

I cheated when I made one for a 4" Burnered 4-Jaw

The square on the end of an old HSS Tap was just the right size. … so I drilled & tapped the end of a mild steel rod for the body, and Loctited the tap in place.

MichaelG.

[Ian PParticipant @ianp]

Michael

Your chuck key worries me!

In my experience, HSS taps are specially designed to break. When they do they leave jagged shards of steel that could injure you.

Ian P

[Michael GilliganParticipant @michaelgilligan61133]

Ian,

No worries here … The full diameter of the Tap Shank is counterbored into the body, and Loctited.

[and, by the way,  there is no reduced diameter "neck" on this particular tap]

MichaelG.

.

Edited By Michael Gilligan on 16/04/2013 20:58:32

Edited By Michael Gilligan on 16/04/2013 21:12:07

[John McNamaraParticipant @johnmcnamara74883]

Hi Tony Bastic

A while back I needed a key and all I could find at the time was a longish 12.5mm Hex cap screw. I cut of the head and ground four flats on the end. Then brazed the other end to a piece to mild steel to make a handle. (With key end protected in wet rag to stop the brazing heat affecting the temper). It lasted for at least ten years….. well at least until I sold my old flat belt change gear Colechester.

Good quality cap screw steel is tough. and you don't have to harden it. It also machines rather nicely.

Cheers

John

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