Thread type

[Richard Clare 1Participant @richardclare1]

Hi All,

I have a brass door handle with a 5/32" xd 30 TPI grub screw. Can you tell me what thread this is? Could it be BSB?

[Richard Clare 1Participant @richardclare1]

Thread type

[John BaronParticipant @johnbaron31275]

Hi Richard,

Could be Cycle thread, 5/32 CSI 30 tpi.

[SillyOldDufferModerator @sillyoldduffer]

Fitting a bathroom privacy lock last week I graunched the grub screw with an incorrectly sized screwdriver and had to re-slot it. Taking the grub out, it appeared to be M4 with an unusually coarse pitch. Reminded me of Meccano, which is 5/32" Whitworth, 32 tpi, but I didn't try one to confirm!

Dave

[Howard LewisParticipant @howardlewis46836]

Unlikely to be BSB since this 26 tpi for all sizes.

If it is not a special, some possibles might be:

Cycle thread 5/32 x 32 tpi, Whit form. CEI is 60 degree.

It might be an undersize 8 – 32 UNC (0.164 OD x 32 tpi ) again 60 degree form.

M4 would approximate to 0.157 x 36 tpi so unlikely

3 BA is 4.1 mm ( 0.161 0 OD ) x 0.73 mm (34.8 tpi approx ) Pitch. 47.5 degree form.

Howard

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