12-28 UNF Threads? (1 Viewer)

[4Cruisers]

Other than the seat belt mounting bolts has anyone else run across non-metric threads on a stock Land Cruiser? I'm trying to determine the thread size and pitch for the jamb nuts on the vacuum advancers, the double nuts used to set the maximum vacuum advance. The thread pitch is between 8mm and 10mm, and the thread diameter is about halfway between 5mm and 6mm. After quite a bit of Internet searching I think it may be a 12-28 UNF thread. I'll run over to the hardware store later this afternoon and see if a 12-28 UINF nut will thread onto the advancer's actuator rod.

 

[4Cruisers]

I was able to find a 12-28 UNF machine screw at the hardware store, in the bin with gun screws. It's close enough for what I need - probably close to a 5.5mm x 0.9mm pitch. I did find a metric thread pitch gauge at McMaster-Carr that has a 0.9mm pitch. It comes with a screw/bolt size gauge that includes a 5.5mm diameter hole, but I've never seen reference to a 5.5mm x 0.9mm machine screw.