Help In Identifying a Vintage Lathe Collet Set

[Maui]

I've got a complete set of lathe collets that I picked up at a local estate sale recently. I thought that they might be for an old Hardinge lathe, but the dimensions don't appear to be consistent with Hardinge collets. They measure approximately 0.629" in outside diameter at the shank, and about 0.867" in diameter at the head. The overall length is about 4.425". I'm stumped - they don't seem to match the dimensions of any American collets that I can find. They don't have any identification markings on them either other than the size stamped on the head (which appear to be in metric) and an "X" that is stamped onto most of them next to the keyway at the base. And I don't know what the thread is. Any ideas?

Maui

 

[Alchymist]

I do believe those are collets for a watchmaker's lathe, altho they look a little longer than most.

 

[justanengineer]

If its not listed in either Shopswarf or the Hardinge catalog, then Id ask over on the PM board.

http://shopswarf.orconhosting.net.nz/collet.html
http://www.practicalmachinist.com

 

[454ragtop]

Might be Lorch, .629 is about the same as 16MM. http://www.lathes.co.uk/lorch/page28.html
HTH, Jim

 

[Maui]

Jim, you may have hit the nail on the head. Thanks!

Maui

 

[zkling]

Measure the thread pitch please. I think I know what they are, but am not positive.

 

[Maui]

I don't know if I've got a metric thread pitch gage, but I'll do my best to figure out the thread pitch zkling. What do you think they are?

 

[Maui]

The thread pitch looks like it is 20 threads per inch. I also attempted to match it to a metric thread. The closest that I could find was 1.25 threads/mm, but I could tell that it was off slightly. The outside diameter of the threaded end is very close to 9/16", and the diameter at the thread root is 0.540". Any idea who made these collets?

Maui

 

[Maui]

zkling, any guesses?