Silly Starrett Thread Search - 'duckbill' V-block

middle.road

Granite Stoopid...
H-M Supporter Gold Member
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Apr 28, 2014
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I've been trying to determine the thread size for these in order to replace the missing clamp screws.
I believe that they are 1/4-??
I've given it over an hour of 'googling' which is my patience limit and
I'm about to ruin them and just drill them out for 5/16-24 or something.
Would anyone here happen to have one that they could measure and let me know?
Thanks, _Dan
55027-8cb131d88d2758e741758e6a6f6a5756.jpg

Starrett_Duckbill_r_002.jpg
 
Hopefully one of the members here has one they can measure. Starrett and Brown & Sharpe were famous for using proprietary thread sizes. As a work around, if no one comes forward, take a wood dowel and turn to a diameter that you can screw in to the clamp by hand. remove the dowel and then you should be able to measure the TPI imprinted on the dowel. You can measure the major diameter of the internal thread with a spring caliper with the legs ground down to fit in the thread. With that information you can single point thread the bolt in your lathe. That is, if it isn't some oddball pitch that your lathe will not cut, which happens with some tool manufactures special threads. Brown & Sharpe used a lot of 50tpi threads for example.
Hope this helps.

Darrell
 
Hopefully one of the members here has one they can measure. Starrett and Brown & Sharpe were famous for using proprietary thread sizes. As a work around, if no one comes forward, take a wood dowel and turn to a diameter that you can screw in to the clamp by hand. remove the dowel and then you should be able to measure the TPI imprinted on the dowel. You can measure the major diameter of the internal thread with a spring caliper with the legs ground down to fit in the thread. With that information you can single point thread the bolt in your lathe. That is, if it isn't some oddball pitch that your lathe will not cut, which happens with some tool manufactures special threads. Brown & Sharpe used a lot of 50tpi threads for example.
Hope this helps.

Darrell
Cool! Dang I forgot about that trick... Thanks for reminding me.

_Dan
 
Don, that sure beats my method.:) Does Starrett offer drawings like that for us common folk and if so where would one look?

Thanks
Darrell
 
/me grabs a cup of coffee and charges out into the shop to rummage through all my old dies packed in a cigar box.
(Since neither of the lathes have their threading dials currently working...)

-=- Man, I love this forum! -=-
 
Dan, check out www.victornet.com They have dies for special threads. A 1/4 24 is $11.50. What is replacement cost of screws from Starrett ?

Darrell
 
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