Forum

[Norm]

Mark, problem with gearbox screws is you can use BSW or UNC to cover 1/4 x 20 tpi. I would say that 20 TPI is the correct thread

[simon]

Ah ha! 1/4 BSF is 26 tpi!

[Norm]

And 1/4 BSF is equivalent 1/4 BSC (British Standard Cycle)

[simon]

So true!

[MadMike]

Simon, Norm......So wrong. The BSF and BSCY thread forms are different. I think you will find the Whitworth form has a 55 degree thread angle and the Cycle form is 60 degrees. Whilst you can fit the screw into either of the female thread form you will be stressing the threads and seriously risk stripping the threads. HTH. Both thread forms are readily available so it is worth getting the correct match of female and male thread forms as you will be able to tighten them correctly without the risk.

[Peter 53]

Sorry to "hijack this THREAD" (Alan R would have been proud of that!) but this is for NORM:
Do you know much about the Australian Dragon Boat mob? My sister-in-law has been selected to compete for the team in Hungary this summer, and we are thinking of going over to see her (I've never met any my wife's Aus family).

[simon]

Your right Madmike! Good site http://www.britishfasteners.com/threads/bsc.html

[Norm]

Mike,
Nothing in these bizare threads are readily available here we have to order them from the UK.
Peter, only time I have heard of the Dragon Boats is during our Moomba carnival in Melbourne in March

[simon]

Yes stocks of BSF ran out a long time ago here and Whitworth is running very low. As for Whitworth head sizes for the truly obsessed they are only obtained at swap meets and the like unless of course you make them. There are a few close matches but most get milled up as required. Getting the cadmium plated is the next hurdle as funnily enough Platers find the low demand and lethal nature off putting but I've had a fair bit done and there is no question it looks the part.

[Norm]

Simon, most platers here are long gone EPA made sure of that