Re: Any ideas?

A Screw Plate. are you sure all the holes are threaded. It looks like one that had plain holes for each size to gauge with.

Tom

any pictures ?

Mart> >

I have no real idea but it looks similar to a device I use for 'bluing' screws or screw heads.

Mark

In a 1958 copy of the Buck & Hickman tool catalogue there is a picture of something similar but without the handle. It is 'Roebuck' Combination gauge. However it has three rows of holes, the centre row of holes are B.A. (0 to

10) Standard sizes, the left side is the drill size for tapping and the right side is for testing diameter and thread finished work.

Could the one pictured be a basic/cheap GO/NOGO type of thread gauge?

Andy M

milestones snipped-for-privacy@hotmail.com

Thanks for the ideas. I cannot identify all the threads but the smallest one is 6BA, there is also a 4BA but I cannot fit any of the others. If it's a thread gauge I don't know how the individual threads can be identified as there are no markings. There are no cutting edges so I don't think it can be used as a die plate.

Thanks to everyone who replied. I also asked the Science Museum, here is their reply This is the reply I got from the Science Museum; Thank you for your enquiry, which has been passed to me by a colleague.

We have a number of these items in our Hand and Machine Tools collection, which look very similar to yours. It is (or rather, was) a screw-plate, for cutting threads. Perhaps it was converted for measuring different gauges of metal rod, which would account for the lack of a cutting thread on the circumferences of the different-sized holes. I doubt it would have been a thread gauge.

I hope that answers your question.

Regards,

Ben Russell Curator, Mechanical Engineering Science Museum Exhibition Road London

I've got to say I'm surprised at the Science Museum's dearth of knowledge on the subject. BTW, You never got back to me on my query, Fred. I found quite a few in some of my old catalogs and the common descriptive term was "Lancashire Screw Plate." Later versions have two swarf breaking holes interrupting the die thread. A Google search of "Stubs screw plate" brings up an interesting page at the Davistown Museum site:

A firm that started in 1777 and still in business today.

Tom

Big Snip

Hi Tom, Still going but not owned by Stubs anymore. I retired as a telephone engineer 9 years ago & throughout my 40 year career I watched the slow decline in Stubs products from the early years in Scotland Road to the years in Wilderspool Causeway. The sadest part was when they stopped making Stubs famous files. In 1957 when I first visited they still had a few skilled hand file cutters. The later years were all machine cut but still very good quality. The current remnant is shown at

ground silver steel) Now owned by the Ascot Group.

There's nothing more annoying reading a discussion about something you cant see because there are no pictures, what are you lot looking at?

Mart> >

Martin, big brother must have deleted the image.:-) Copy here:

Top one is Fred's Bottom one is a later version with chip breakers. The two holes for each size allowed two step thread cutting.

Tom

AH! Thanks Tom.

Colloquially known as "cake slice" taps, they were used extensively by clock and watch makers. It may well be 100 years old or more.

I've got a couple of them and in this form they are mainly used for cleaning up screw threads. The one in the catalogue is more commonly used for screw making, naturally.

AFAIK, they were the first attempt at a standard thread form.

Regards,

Kim Siddorn

that would be a die, not a tap.

you can only cut a male thread with those things