Viking face bonnet motif - thread ?


Well-Known Member
Can somebody advise what thread is used on the bolts that fix the badge to front of p4 bonnet please? Dia ~3/16, thread 30 or 32 tpi (they are bit second hand).
Good news is no sensible people make 30 TPI threads so i'd go with 32 TPI. Also BSF 3/16 are 32 TPI. however UNF no. 10 are also 32 TPI but 0.1mm thicker. In reality in terms of nuts you will probably find that either will work; difference being in the angle of the thread, UNF being 60 degrees while BSF is 55 degrees. From a practical perspective I'd use BSF as they are far less likely to jam, rust on etc. even if the thread angle is mismatched (that was the main reason Whitworth went with the 55 degree angle and fancy curves at the top and bottom of the thread).

In terms of actually buying them Coventry fasteners have them if local car places don't but they usually ask for a fifty dollar purchase mimimum. Alternative I have some I can post down in an envelope next trip to the shed. the No. 10s are common on P6 but listed as 3/16 so you may have some.
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Re "Good news is no sensible people make 30 TPI threads" - if this is true, why is there a 30tpi blade in my thread gauge? Somebody out there makes non-sensible screw/bolt at 30tpi? Is that worse than Peugeot making a bolt with a five sided head?