Stanley Bridges drill- thread size

[John Rudd]

Ok, got this electric drill made by S-B.....one of the screws holding the gearbox to the casing has sheared...I'm having difficulty in identifying the thread.

With thread gauges, its either 32 tpi or 0.8 mm in pitch, the diameter measures approx 0.158 in or just over 4.01mm

It isnt metric, nor is 5/32 BSW....I dont think its UNC because the diameter is smaller than an 8-32 bolt form.....

Any other ideas?

[philf]

Hi John,

8-32 UNC would be my guess. Screws are nearly always smaller than the major diameter quoted and that for 8-32 is only 0.164 so your screw is only 6 thou less which I would think is fairly typical.

Cheers.

Phil.

[John Rudd]

Thanks Phil,
Now need to search out a tap/die set....

[philf]

John,

I have a spare die if you want it.

Phil.

[John Rudd]

Phil,
Would that be a split die then?
How much are you asking for it please?
Maybe we should take this off line via pm?

[John Rudd]

Just to update this thread...
Phil was right on the money with his guess...