- Joined
- Nov 2004
- Messages
- 21,418
"Metric" ?
"So, the list of BA thread sizes is reached on the basis of a list of sizes, each 0.9 times the size of the previous, starting at 6.00 millimetres. This list is then rounded to the nearest hundredth of a millimetre, equivalents in 'mils' or thousandths of an inch are approximate. We have to face the truth, British Association threads are well and truly metric."