Unusual die?

I have found a 1/4" x 26ME die in my collection the likes of which I have never seen before. It came from my late father and could even have belonged to my grandfather, so I estimate it to be at least 60 years old. The self expanding feature is what I find unusual, the die is fitted with a tapered screw with a tapered nut, this thread being 8BA and obviously there are mating tapers in the body of the die. Tightening this screw effects the expansion of the die which has a logo for GTD and U.S.A. etched into it. Just wondering if anybody here can shed any light on this, it never ceases to amaze me the wealth of knowledge that exists on this forum.

Sorry about the quality of the photos, I'm afraid photography is not one of my strong points.

Phil

I've seen dies like this before but never with the adjuster. I imagine the basic die is set to cut slightly undersize and the adjuster used to set the fit required. Setting will be retained when the die is removed from the diestock.

With a normal die the adjustment is lost when the die is removed so for precise work it has to be reset each time. If you want to retain adjustment between uses with a normal die you need to make up a carrier with the requisite screws and leave the die in that. Geo. H. Thomas advocated this and published designs for his set.

Wonderful idea but a set of such carriers another project I shall never get round to.

Clive.

Edited By Clive Foster on 26/02/2017 13:24:18

Very nice little die, Philip ... Treasure it.

Makes the common arrangement look rather unsophisticated !!

[even if they do work]

MichaelG.

Here is an excellent little book by GTD **LINK**

https://babel.hathitrust.org/cgi/pt?id=uc1.$b76765;view=2up;seq=126;skin=mobile

MichaelG.

.

P.S. The GTD trademark appears to be owned by Kennametal:

https://trademarks.justia.com/711/41/gtd-71141980.html

... and, historically, 'Canadian Tap & Die Ltd.' of Galt, Ontario may be of interest:

http://progress-is-fine.blogspot.co.uk/2012/04/we-used-to-make-things-in-this-country.html

Edited By Michael Gilligan on 26/02/2017 15:41:07

I've several dies that are tapped through the "split" and have small grub screws so they retain the setting when removed from the die stock but not seen one with the tapered screw & nut before.

J

I have a tap and die set mace by Champion Forge and Blower. They use similar expander screws. It is also unusual by having an alignment bushing that fits into the die stock behind the die. The die stocks are beautifully color case hardened. By contrast the tap wrench is bright plated, maybe nickel.

Thanks for the replies chaps, it would appear that its not totally unique but worth keeping if only to go in my personal curio museum, aka junk box.

Phil

Sorry finger trouble. I meant to say what a wonderful name for a company.

Martin