Tap and Die sanity check

[winchman]

Sorting through some boxes as i do have a few too many
26TPI is Cycle?
32 and 40 TPI are ME ( Model Engineering) I suppose a modern BA?
Found a Left hand 5/16 BSF any ideas of an application?
Thanks

 

[awemawson]

26 TPI can also be BSB (or British Standard Brass) - used on many lighting fittings

 

[winchman]

26 TPI can also be BSB (or British Standard Brass) - used on many lighting fittings

Thanks I do have a few BSB, I just need to sort out but dont want to part with any I might need, the Cycle are very handy as we both like old motor bikes and Pushbikes
As usually very few are in bed sets so I am hoping to make a few boxes like the wooden Presto ones to keep them in as they are so handy when you need them

 

[optima21]

BA and 32/40 pitch threads are separate types in their own right, nothing to do with one another

 

[Hopefuldave]

BA and 32/40 pitch threads are separate types in their own right, nothing to do with one another

Yep, BA are based around metric dimensions, but in a peculiar way...

Starting with 0 BA, 6 mm major diameter 1 mm pitch, other threads the pitch in mm is 0.9. to the power of the BA number, rounded to 2 decimal points, the diameter is 6 x (pitch to the power of 1.2) rounded to 1/100 of a mm like the pitch... possibly the most awkward system on earth, with a deceptively simple definition... I suspect it was designed by a commitee. The curious 47.5 degree flank angle came from defining the thread depth and the root and crest radii, they had to join up with the flanks...

Dave H. (the other one)

 

[Pete.]

Yep, BA are based around metric dimensions, but in a peculiar way...

... I suspect it was designed by a commitee.

With a name like British Association, I expect you are right

 

[RichardM]

1/4 BSF are also 26 tpi @ 55 deg
5/16 BSF LH turnbuckle adjuster,