P3 75 floor panel fixing

[Hud60]

I have taken the floor panels out of my P3 75 to restore. I have removed all the fixing bolts which fix into the captive nuts on the outer frame and chassis. I'd like to replace them. What thread are they? I thought they were 1/4BSF but they seem to be slightly finer thread. Many thanks for any help.

[David2021]

Possibly 1/4-28 UNF?
David

[HAD501]

It’s a while since I did this job on my P2, but I’m sure the screws are 1/4BSF. So it would be reasonable to expect the same on P3’s as you suggest. No knowing what previous repairers have done I suppose. Have you tried running a 1/4BSF tap into the captive nuts?
Hope that helps, DaveM

[David2021]

For what it is worth...My P2 floor screws are all csk1/4 26 BSF x1" or 1.1/4" cone pointed. The many missing dished floor board washers I have made up from " Tile/Roof-nail washers" ! They have a 5mm hole, easily opened up to take the 1/4" screw. Available by weight on e-bay. 225grammes was enough, they are a bit thinner than the originals, but do a good job.