unit(단위)=mm type dimension D d E øC h h₁ h₂ 허용하중 J BC-1" 70 56 51 5.5 31 23.5 18 25 kg J BC-1¼" 86 70 63 7 39 31 22 50 kg J BC-⅝ 48 40 32 4 21.5 16 14 15 kg J BC-1½" 76 62 62 7.5 47 34 85 kg
unit(단위)=mm