noun
: a screw thread sometimes used in American watches and having a V profile with a 45-degree included angle for nickel and brass and a 60-degree included angle for steel
noun
: a screw thread sometimes used in American watches and having a V profile with a 45-degree included angle for nickel and brass and a 60-degree included angle for steel
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012