| Diagram | Fig. 29 — FENDERS · ref 19 |
| Subsystem | frame |
| Listed in parts books | 1969–1974, 1976–1980, 1983, 1985 |
Nut, cylinder to frame bolt 5/16" UNF self locking
A 5/16 inch UNF self-locking nut used in numerous mounting and fastening points across Triumph and BSA models.
This is a 5/16 inch UNF self-locking nut, the kind Triumph and BSA used across dozens of different jobs on these bikes rather than any one single spot. It shows up in cylinder-to-frame bolting, footrest and engine mounting fittings, exhaust bracket hardware, fender and tank fixings, and plenty more places where a fastener needed to stay put under vibration instead of backing off.
Read more
The self-locking (Cleveloc-type) feature is what sets it apart from a plain nut. It grips the bolt threads with enough resistance to hold its position without a lock washer, which matters anywhere on the bike that sees constant engine vibration and road shock.
With over two hundred catalog listings tying this same PN to fender brackets, gearbox covers, exhaust mounts, tank fittings, and more, it is one of those parts worth keeping a small stock of on the bench. Given how many different assemblies call for it, check your specific bracket or fitting against the parts book before assuming this is the exact nut needed for your repair.
Sorry if we got something wrong here. If you think this information isn't correct, .