钻杆

It can be divided into two groups: Group 1--Grade E drill pipe Group 3--All high strength grades of drill pipe .(Grades X-95, G-105, S-135) a The minimum elongation in 2 in.(50.8mm) shall be that determined by the following formula: e=625,000A0.2/U0.9 where e = minimum elongation in 2 in (50.8 mm) in percent rounded to nearest 0.5%. A = cross-sectional area of the tensile test specimen in square inches, based on specified outside diameter, or nominal specimen width, and specified wall thickness rounded to the nearest 0.01 in.2, or 0.75 in.2, whichever is smaller. U = specified tensile strength, psi. Note: See Table 5 in API SPEC 5D for minimum elongation #118alues for various size strip tensile specimens and grades. The minimum elongation for either round bar tensile specimen (0.350-in. diameter with 1.4 -in, gauge length and the 0.500-in. diameter with 2.00-in. gauge length) shall be that shown in Table 5 for a cross-sectional area "A" of 0.20 in.2.