     ISS-1239 Steel Tubes And Tubulars (Light, Medium, Heavy)  Unit Weight Calculation Method: 1.API, ASTM, AISI Standards W - 10.68(D-t)t W= Weight per unit length(lb/ft) t= Wall thickness of pipe(in) D= Outside diameter od pipe (in) The result of calculation is rounded to two places of decimals 2.BS Standards W - 10.68(D-t)t W= Weight per unit length(lb/ft) t= Wall thickness of pipe(in) D= Outside diameter od pipe (in) The result of calculation is rounded to a three figure number 2.JIS Standards W - 0.02466(D-t)t W= Weight per unit length(lb/ft) t= Wall thickness of pipe(in) D= Outside diameter od pipe (in) The result of calculation is rounded to a three figure number Conversion of Unit 1.API Standards W(lb/ft) x 0.454 = W/' (kf/ft) W, W'= Weight per unit length W'=To be rounded to two decimal places 1.ASTM Standards W(lb/ft) x 0.45359237 = W/' (kf/ft) W, W'= Weight per unit length W'=To be rounded to two decimal places 1.BS Standards W(lb/ft) x 0.45359237 = W/' (kf/ft) W'=To be rounded to three figure 1.Length L(ft) x 0.3048 = L'(m) I(in) x 25.4= I(m)