What is it

[Roger HulettParticipant @rogerhulett83124]

Starrett thread gauge (gage)

[Roger HulettParticipant @rogerhulett83124]

I have acquired a Starrett thread gauge, No 7. But what does it measure?

There is no description in the Starrett catalogue and the only one on fleabay has no description.

This gauge has 26leaves. The largest is marked 4 – 320 the smallest is marked 48 – 026

I have a whitworth gauge where the largest is marked 4 – 2 1/2 – 2 1/4 and is a close match to the 4 – 320 Starrett, but no others seem similar ? ? ? ?

[SillyOldDufferModerator @sillyoldduffer]

Like this:

I have a Starrett Tools 50th Anniversary Catalogue from 1930. I knew it would come in useful eventually!

Dave

[Anonymous]

It'll be the equivalent thread gauge for US threads. The first number is tpi. The second is at, or close to, the width of the flats on a US thread in tenths. Although why you'd need that I don't know. The figures after the 4 on the Whitworth gauge are the bolt diameters to which that tpi applies.

Andrew

[JasonBModerator @jasonb]

tpi and difference between OD and core dia

Edited By JasonB on 20/10/2016 16:56:45

[Roger HulettParticipant @rogerhulett83124]

Thankyou "Silly Old Duffer"……Whitworth Screw Pitch Gage No 7…………Apart from the W engraved on the casing and the extra 60 leaf, that is the one I have. I note that after the price it states Whitworth Standard Threads only. So it is basically a Whitworth thread gauge, and as I have three other Whitworth thread gauges I can put this one in a museum !

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