THREADS  nut and bolt type, not clothes nor computer lingo

There are many different types of threads, and it is important to use the correct bolt and nut combination to allow for correct tensioning and ability to undo.


Threads used on HD and HR Holdens were imperial (inch) threads mainly UNF (unified national fine) and UNC (unified national coarse). (Perhaps some BA ??)

Abbreviations and links to thread information 

How to measure a thread

Some Imperial threads (in inches)



Some Imperial Pipe threads

Metric threads (in mm's)

Spanner types and sizes

Thread shapes



Disclaimer: this site may be used for interest only. The writer has no qualifications in threads, but has an interest in assisting people to

understand the complex and often confusing area of nuts and bolt threads