Jacobs chuck

[Lurker]

I have a small metal working lathe, most likely a “bitsa” but it’s useful for the little jobs that I want to do.

The static chuck end is MT1. I have a decent spare Jacobs chuck the has a thread in the end, I guess it came out of a dead drill.
I can’t find an MT1 arbor that is threaded, they are all interference fit.

Am I looking for something that doesn’t exist?

 

[9fingers]

They exist on ebay with various different threads. Chronos, RDG and Arceuro are worth tryingtoo

Depends what thread you need. Otherwise buy oversize and cut your own thread.

Bob

 

[Lurker]

Thanks Bob.

Slightly different question…
I have found another Jacobs chuck in my stash, but despite having a box of orphan keys, I can’t find one to match the chuck.
I think that the chuck is numbered so is there some way that I can identify the key that I need to buy.

 

[9fingers]

Look up the Chuck number to get the correct key size
Chronos keep a good range of keys

 

[Lurker]

Look up the Chuck number to get the correct key size
Chronos keep a good range of keys

Blimey!
Is it that easy

 

[9fingers]

Look up the Chuck number to get the correct key size
Chronos keep a good range of keys

Blimey!
Is it that easy

Yes it’s called the internet :lol:
Bob

 

[novocaine]

Cheap like the budgie

oh, and yes, it is that easy.

 

[BucksDad]

As I didn't know what a Jacobs chuck was and still read / post on the other place, this thread triggered me

 

[Woodster]

Many chucks have the thread size marked on them. If not you’ll need to identify the exact size before ordering anything. 3/8” 24 and 1/2” 20 seem the most common but there are others.

 

[Lurker]

Thanks chaps,

The arbor is a cheap way to put a decent chuck back to work.
I had not really looked at all the marks on the chuck and didn’t realise how easy it was to identify what I needed.
I see real Jacobs chucks are quite expensive these days.