Matching numbers on chuck jaws

Hi all, I have just got a new chuck for my lathe and noticed as I was changing int. to ext. jaws the numbers on the jaws. Am I mistaken but should all 6 chuck jaws have the same number stamped on them or just the set of three be the same. I have one set with numbers 111 and the ext. jaws with 3436 stamped on them. There is no number on the chuck to match to anything, any help would be good. My other chucks are in storage and I cant have a look at them.

You should have 1, 2 & 3 on one set and 1, 2, & 3 on teh other.

The 3436 sounds like the part number not the individual jaw number.

Number usually insid ethe grooves on teh chuck that the jaws fit into. Same with jaw mumbers usually inside the slot at the side of the jaw.

What make chuck is it?

Edited By JasonB on 18/06/2016 15:03:00

3436 could be the serial number too.....all too easy to mix up jaw sets across a collection of chucks.

I keep mine seperate and identified with a label to avoid such issues....

the inside jaws will have one number on them and the outside jaws will have another number on them. What you have sounds correct

There should be a number 1, 2 or 3 on each. That is the order in which they are installed in the chuck, due to the difference in screw thread of the chuck., so they all meet at the centre?

Ideally the same jaw should be intalled in the same position in the chuck each time, so the numbers should be stamped on the chuck as well. Clearly a 'matched set' with the same serial numbers should be kept as a set for each chuck.

All to do with consistency and maintaining known accuacy.

As Old Al said, each set will have its own serial number. In addition, each jaw is normally with its position in the chuck. However if the jaws aren't numbered, just look at the scroll teeth on each jaw and place them in increasing "tooth offset" If you line them up with teeth showing, you will see what I mean. Then locate 1 on the chuck, with the chuck key, move the scroll so that it is just about to bite on the number 1 position and put the chuck jaw with the minimum "tooth offset". turn the chuck key a little clockwise and engage the first jaw. follow the process for the next two jaws which follow in an anti clockwise direction looking from the tailstock towards the chuck.
If you get the sequence wrong, then the jaws will not meet in the centre.

If there are no markings on the chuck, start anywhere on the chuck and proceed anticlockwise.
By the way, it is the same method for both inside and outside jaws.
BobH

David,

The numbers you have stated are the matching batch numbers of the jaws, as you assumed these will be different on other jaw sets, obviously they will also be numbered for slot sequence (1,2,3)

I have numerous sets of inside and outside jaws that fit same chuck, all with corresponding batch set numbers, you could have several sets of jaws, but they must always be used with the same batch number.

There are suppliers selling sets of 3 jaws, that have the same physical dimensions but for a 6 jaw chuck, which incidentally would be numbered 1,3,5 for one set then 2,4,6 for the other, but they would all have one batch number.

Strangely enough this came to light when my son bought a Bantam 800, the 3 jaw chuck on the lathe actually had 2 jaws of one batch number and one of another, it worked and centred reasonably, but a new chuck was purchased.

P.S. Sorry I didn't see BobH's posting.

Hope this helps.

Bernard.

Edited By Bernard Wright on 20/06/2016 00:22:05

As well as the single digit jaw number some self centering chucks such as TOS have a serial number on each of the inside and outside jaws. This serial number is the same on all jaws and matches the serial number on the chuck itself. The jaws are ground while in situ in the chuck body for accuracy and the serial number confirms that the jaws are from that chuck. The serial number is usually on the back of the chuck under the backplate.

A few years ago I bought a new TOS four jaw self centering chuck from Chronos. As soon as I recieved it I knew it had already been opened and tampered with because the plastic strapping that seals TOS boxes was missing. Sure enough when I opened it one set of jaws that were rattling around loose in the box were a poor and very loose fit in the chuck body. The serial number on these four jaws did not match the number on the chuck body or the other jaws, plus the accuracy with them was pants.

It looked like the originally factory supplied jaws had been lost and someone at the shop had carelessly thrown in a mismatched set, it may have been a chuck that had been on display at some time. They posted a replacement very quickly, and all eight jaws on this replacement chuck have a serial number that matches that on the chuck body.

All the TOS chucks I use have these matching serial numbers on the body and all its jaws, and also a Pratt Bernard chuck although I only had one set of jaws for that.

Edited By Lathejack on 20/06/2016 00:31:01

Edited By Lathejack on 20/06/2016 00:45:51

Edited By Lathejack on 20/06/2016 00:53:02

Hi all, thanks for the replies. Since putting up this post I have had a look at my other chucks and a TOS chuck I have has all the 6 jaws and the body with the same number stamped on, my latest lathe, Warco 240, arrived last week, has different numbers on the internal and external jaws which confused me.