In 1841 Whitworthdevisedastandardforscrewthreadswithafixedthreadangleof 55° andhavingastandardpitchforagivendiameter.웹 검색 예문소리듣기
JosephWhitworth, at that timeoneofClement'sjourneymenafterwardsplayedamajorroleinsuchstandardisation, theWhitworththreadbecomingastandardformachinescrews.웹 검색 예문소리듣기