Does anyone know where to get the correct nuts and screws for 5 bolt Racer or Flyer crank arms. What is the tread count and size. I've had a few guys asking for them but don't know where to get them.
I understand originals are becoming hard to find, but I recently measured the chainring bolts as M5x0.8....you should be able to use a cap screw of that size and file the head to be square like the original, and either cut them short or add an appropriate nut depending on what you want to use.
Given the era, an imperial size fastener seems more likely than metric. Imperial 10-32UNF is almost indentical to M5x0.8. The major diameter for #10 is 0.190" which is 4.826mm. The pitch for 32TPI is 0.794mm.
Thanks Tom - you are of course correct....reached for the metric stuff first and the M5x0.8 fit "perfectly", and the original crank bolt nut threaded smoothly onto a modern M5x0.8 cap screw I had....of course Imperial makes more sense in the 30s and 40s in Canada.
I tried the M5 and it fit, a little loose on the threads though. What is the standard size for 10-32UNF, I don't think they will be marked that way at hardware stores.
Tom, yes 10-32UNF is the correct and standard name, though some stores may have the bins/packages marked 10-32. Don't worry, 10-32 is the same as 10-32 UNF. It is a very common size, though I doubt you'll find square heads and may not find the exact length. You should be able to get them at CTC, Home Depot etc. If you have to cut to length, thread on a nut first first, so that the nut reforms the damaged/cut thread whan you remove it.
If you want to modify the heads to look like OEM, make sure you buy stainless steel bolts. If you buy plated bolts, the heads will rust where you've removed material. This is almost eliminated if you use stainless steel..
I understand originals are becoming hard to find, but I recently measured the chainring bolts as M5x0.8....you should be able to use a cap screw of that size and file the head to be square like the original, and either cut them short or add an appropriate nut depending on what you want to use.
Given the era, an imperial size fastener seems more likely than metric. Imperial 10-32UNF is almost indentical to M5x0.8. The major diameter for #10 is 0.190" which is 4.826mm. The pitch for 32TPI is 0.794mm.
Thanks Tom - you are of course correct....reached for the metric stuff first and the M5x0.8 fit "perfectly", and the original crank bolt nut threaded smoothly onto a modern M5x0.8 cap screw I had....of course Imperial makes more sense in the 30s and 40s in Canada.
I tried the M5 and it fit, a little loose on the threads though. What is the standard size for 10-32UNF, I don't think they will be marked that way at hardware stores.
I have the original NOS nus and bolts. How many did you need?
John Williamson
this is where I get my bolts, then I modify the head
https://www.boltdepot.com/Tap_bolts_Stainless_steel_18-8_10-32.aspx
and here for harder to find sizes
http://www.harborvintage.com/catalog/page1.html
Tom, yes 10-32UNF is the correct and standard name, though some stores may have the bins/packages marked 10-32. Don't worry, 10-32 is the same as 10-32 UNF. It is a very common size, though I doubt you'll find square heads and may not find the exact length. You should be able to get them at CTC, Home Depot etc. If you have to cut to length, thread on a nut first first, so that the nut reforms the damaged/cut thread whan you remove it.
If you want to modify the heads to look like OEM, make sure you buy stainless steel bolts. If you buy plated bolts, the heads will rust where you've removed material. This is almost eliminated if you use stainless steel..