... .ASTM A53,ASTM A500, ASTM A513, 2.ANSI C80.1 ,ANSI C80.3 3.BS1387, BS1139 4.EN10219,EN10220 ... per inch of ScrewExternalInternalExternalInternalSteelExternal Surface(ft)Internal Surface (ft)lb/ftkg/m1/80.410.270.070.130.060.079.4314 ... 131.360.860.492.903.640.00601.682.5011 ½1 ¼1.661.380.142.161.500.672.302.770.01042.273 ... .3811 ½1 ½1.901.610.152.842.040.802.012.370.01412.724 ...