ISO M20 Trapezoidal Thread. Based on information from https://mdmetric.com/tech/thddat16.htm.
Berlin 2009 – Usain Bolt with a New World Record in 9.58 over 100 m
“Asafa Powell is the fastest out of the blocks – now it’s Gay in the lead and now is Usain Bolt – no holding back – no, he wins – 9.58 WR”