單項選擇題

用夾剪剪直徑3mm的鋼絲(如圖所示),設(shè)鋼絲的剪切強度極限τ0=100MPa,剪子銷釘?shù)募羟性S用應(yīng)力為[τ]=90MPa,要求剪斷鋼絲,銷釘滿足剪切強度條件,則銷釘?shù)淖钚≈睆綉?yīng)為()

A.3.5mm
B.1.8mm
C.2.7mm
D.1.4mm