Source of 1/2" BSP tap (as in thread cutting)?

[Roger Mills]

I'm shortly going to replace all my radiator valves with TRVs and drain-off lockshields and reckon that it's probably a good idea to clean up the threads in the rads to get rid of accummulated gunge (dried up Boss White etc.) before screwing in the new tails.

Any idea where I can get a 1/2" BSP tap (plug rather than taper) for the purpose? It doesn't need to be exotic, and won't be cutting new threads - just cleaning up old ones. The sheds and local PMs don't seem to sell them - nor do Screwfix or the likes of BES as far as I can see.

[dennis]

should be enough I would think.

[The Natural Philosopher]

Try street markets and the like. Lots of old taps/dies etc from specialist purveyors of dead men's sheds' contents...

[Roger Mills]

Thanks - but that's just a wire brush. I'm really looking for something which actually screws into the thread and cuts out all the accummulated crap.

[Mark]

Ebay

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[Dave Plowman (News)]

Cut a couple of longitudinal slots down one of the old ones - that should act as a tap to clear out any gunge. Perhaps better still get an iron fitting and do it to that. Although brass should be ok.

BTW, the drain off lockshields work only for the pipe side if you close the lockshield. IIRC.

[Roger Mills]

Possible, I suppose - and this *is* a DIY NG! But I think I'd rather have the real thing.

No - the other way round. The drain *always communicates with the rad regardless of whether the valve is open or closed. So close the valve to drain the rad while keeping the water in the pipe, and open it to drain the pipe as well.

[1501]

Try

If they can't help nobody can.

[Ed Sirett]

That's what i would expect also.