Are all rad bleed screws the same?

[Nick]

Previous occupant has used pliers/mole grips etc to bleed rads. All are well rounded and a key will not work. All rads are pressed steel. Some have the bleed screw within a (1/2" square) screwed in retainer, on others the retainers are welded to the rads. The remains of the screw heads look different sizes. Intention is to drain the system, replace all bleed screws, inject inhibitor, refill system, cross fingers and walk away with a smile. Hopefully. I'm just wondering if these bleeding screws may be different dias/threads and would like to be prepared beforehand. I presume rad bleed screws of whatever flavour are readily available. Thanks, Nick.

[harry]

All the ones I have come across are the same. However, I have never seen the screw bit for sale separately.

[Jim K]

I've come across bleed screws with different "odd" head sizes too, usually fitted in unusual positions on the rads. No idea if the threads were different tho.

You can buy new rad air vents (with bleed screws) for peanuts from toolsatan et al.

Jim K

[PeterC]

About 12 years ago I needed some bleed screws to replace some slightly leaking ones - they'd been overtightened and had steps on the tapers. Down the road was a proper Plumbers' Merchants, run by plumbers who were very experienced and helpful (closed now :-(( ) and even they couldn't get any. I used a tiny smear of Boss White on the face and thread and they're still functioning. Seems bloody daft to have to buy a big chunk to get the little bit that you want - rather like wimmin, innit.

[Jim K]

64p each for the whole air vent? it's hardly a ball breaker is it?

Jim K

[Tim Lamb]

I have re-finished taper seat valves (carburettor floats) by rotating the shaft in an electric drill against an abrasive surface.