Thread: Early Series 2A wheel studs: metric options?

Originally Posted by jakeslouw

So a M14mmx1.5mm Thread Pitch will work?

The metric tap will just alter the thread angle to 60 degrees from 55 degrees?

1. The thread angle will change as you correctly predict; however; because there is a difference in pitch of 0.08mm you need to take that into account. For every revolution of the tap the pitch will mismatch by 0.08; and then by 0.16mm for the second turn; and then by 0.24 for the third turn, and so on. Eventually the mismatch will become so pronounced that the thread tooth is likely to have a malformed crest and root and eventually greatly reduced tooth height. This may weaken the female thread enough to cause it to be a safety issue.

2. 9/16" = 0.5625" which equals 14.2875mm; therefore the 14mm tap will be undersize when compared to the crest diameter in the female thread.

3. Can you buy 14mm wheel nuts with the correct end-profile to fit the Rover rims?

In my opinion it would be unwise to adopt this procedure on any thread which you want to stay clamped, and more so on a safety-system.

Why don't you buy some high-tensile steel such as 4140 High Tensile Steels | Interlloy | Engineering Steels + Alloys and cut the appropriate BSF threads on them using a 9/16" die?

Cheers Charlie

Thanks Chazza

Option 2 now appears to be to source some 9/16 BSF long bolts or studs in HT and cut them down to length of 43mm+.

Or else buy some bloody studs from the UK.