Thread: P&N / Sutton Tap Wrench Size for 1/2" BSP Tap?

Hi, why not 2 pieces of 16mm square bar and cut/file/machine a notch in each bar about 50mm in from the end of each bar, drill 2 hole that line up and bolt together, as were the tap handles of yesteryear. You've just saved about $80 for an hours work. May be not as fancy, but it will work.
Kryn

Originally Posted by KBs PensNmore

Hi, why not 2 pieces of 16mm square bar and cut/file/machine a notch in each bar about 50mm in from the end of each bar, drill 2 hole that line up and bolt together, as were the tap handles of yesteryear. You've just saved about $80 for an hours work. May be not as fancy, but it will work.
Kryn

Good thinking.

I have a Greenfield GTD No. 6 which measures 17.6 mm on maximum opening, and a P&N No. 7 which is bigger, but out in a cold dark container. I can check tomorrow if you like for its maximum capacity. I am not sure how the number sizes from different manufacturers compare, but I would be a bit surprised if all number 7s were the same, no matter the manufacturer, but perhaps there is a convention on sizes, - I just don't know.
It would seem that if most manufacturers sizes roughly line up, then you are looking for a No. 5 or 6 for your BSP tap, but a couple of pieces of 1/2 or 5/8 key steel and 2 suitable SHCSs would likely be much cheaper, as has already been suggested.
Rob

Originally Posted by ventureoverland

Guys,
My 1/2"BSP tap's won't fit in my Starrett 91D tap wrench - Its a little too small.

P&N and Sutton (are they the same company now?) seem to make bigger ones, but non of the spec's Ive looked at give the Min & Max shank size.

My 91D max's out at an 11mm shank and my 1/2" BSP shank as about 12.5mm.

Does anyone know which size tap wrench covers this range? I think it could be a P&N No5 or No7 but am far from convinced!

My P&N No. 6 can only handle around 11.3 mm.

Dean

I just ducked out to the shed an took a few measurements of the different P&N tap handles I've got, I measured between the jaws fully open (J) and across the slot (S) which seems to be the limiting dimension.

Smallest J=8.75mm (11/32) S=8.2mm
No 0: J=10.9mm S=9.7mm (3/8")
No: 5 J=15.7mm S=12.7mm (1/2")
No: 6 J=18.0mm S=16.5mm
No: 7 J=26.0mm S=25.7mm
No: 7B J=31.8mm S=28.8mm (1 1/8")

The small one is part of a P&N set but isn't marked.
I expected some uniformity with the fractional measurements but only those indicated were dead on.
Hope this is of some use.
Cheers,
Greg.

Quick update on this.

I dropped on a No7 P&N wrench and its plenty big enough for a 1/2"BSP tap.

Apart from the nice quality of the unit, I really like that one of the handles unscrews. This means that in conjunction with my spring centre in the tailstock I can easily use it on the lathe (I had thought it maybe too big).



Thx
Jon

I'm curious to which type you referring to?


The Bar Wrench or T- Handle versions?



Some variations on the Off set tap wrench, shop made variety suggested.


Some more advanced designs with plans & instructions here:
http://www.hteck.ca/metalworkings/ta...ap-wrench.html

Bar Wrench.
Interesting links though, I'll have a look in more detail later. Perhaps another practice project coming along


Thx
Jon

I like the ones in the bottom image for two reasons.

1. The handles form the bolts
2. The jaws can be flipped so there is a small and large vee, to accommodate a broader range of tap ends.

Originally Posted by DSEL74

Some variations on the Off set tap wrench, shop made variety suggested.

These bring back memories of my school days, when I moved up to secondary school and had to take metalwork as well as joinery. We had to make one of these tap wrenches. We had to file out the V's, mark and drill the holes for tapping. Then we had to use the first wrench that was produced by one of the class to hold the tap and tap the hole. Apart from the fact that we had to pay for the materials we used we also had to pay for the taps that we broke. I'll confess now that mine went into the scrap bin at the first opportunity.