7–20 August was when it was held . 28 from 28 nations,313 from 65 nations were the competitors in Men's welterweight boxingat the Games of the XXXI Olympiad . 17 teams participated in Men's welterweight boxingat the Games of the XXXI Olympiad . The no. of events in sport was 14 . The venue for Men's welterweight boxingat the Games of the XXXI Olympiad was Olympic BMX Center (BMX),Riocentro – Pavilion 6,Field . The sport has the official site www.hardrock100.com . 5 September 1971 is when Men's welterweight boxingat the Games of the XXXI Olympiad was established 
There are 21 teams in sport Men's welterweight boxingat the Games of the XXXI Olympiad