BSP threads

[MacKiwi]

I ordered a bunch of stainless fittings and valves from BES. Most seem fine, but I ordered a bunch of 1/2" BSP locknuts...

14547 1/2" stainless steel 150 lb screwed hexagon locknuts...

And for the life of me I can't get them to screw on to any of the fittings. As soon as the thread is fully engaged they jam and will go no further.

The fittings are generally described as having BSPT threads. The locknuts just BSP. Is this a critical difference?

 

[joe1002]

Have a read here

 

[MacKiwi]

Thanks Joe - that thread is spot on. Pity I didn't read it 1st

Just spoken to BES on the phone. They say that the lock-nut is BSP parallel thread, whilst the fittings are BSP tapered. The fittings on their catalog page have BSP and BSPT to distinguish this. The bloke mentioned that the nut should go about 3/4 of the way up before tightening, but for me it only makes it about 1/5th of the way. Apparantly this is due to "tolerances".

Well, to me, they are just plain incompatible, so the lock-nuts are going back (which they were fine with, to be fair).

Anyone know where I can get some 1/2" BSP stainless locknuts that do work?

 

[borischarlton]

How many do you need?

 

[MacKiwi]

At least a dozen. I actually ordered 24 from BES, thinking they would be useful to have around...

 

[borischarlton]

I am just doing a BES order now, I can add a dozen on and tap them for you if you like?

Rob

 

[MacKiwi]

That would be fantastic! I believe you are the Rob of Malt Millar fame - I was about to put in an order for some grain and the john guest push-fit fittings (i emailed you about stock earlier today), so this could work out nicely. Will send you a PM....

 

[Vossy1]

Only 3 or 4 weeks ago I complained to BES again, nothing has been done. They called me back to say they'd checked all the nuts in the bin and only 8 were found to be faulty I bet they check them against a taper thread...numpties!