JIS G3445 STKM 15A Drawn Over Mandrel Steel Tube Seamless And Electric Resistance   Product Name:Carbon steel tubes for machine structural purposes Appilication: Machine Auto competent Furniture Bicycle Mechanical parts Mechanical Elements machine elements   1.Grade STKM 11A STKM 12 (ABC) STKM 13(ABC) STKM 14(ABC) STKM 15(AC) etc Standard JIS G3445   2.OD:4-60mm,Wall thickness:0.5-7mm   3.Characteristic:The tubes are high precision in tolerance   4.Kindly advise heat treatment requirement if any. HR CW SR A N HF HR:hot rolled CW:cold worked SR:stress relieved A:annealed N:normalized HF: hot formed.   5.STKM 15A Chemical composition % max: C:0.25-0.35 S:0.35 Mn:0.30-1.00 P:0.04 S:0.04 Mechanical properties:min Tensile strength 470Mpa Yield Strength:275 Mpa Elongation:22% Use in Cross member,Frame side member,Axle tube,Valve locker shaft, Steering system, Extract tension tube Tolerances on OD Division Tolerance on OD No.1 under 50mm ±0.5mm 50mm or over ±1% No.2 under 50mm ±0.25mm 50mm or over ±0.5% No.3 under 25mm ±0.12mm 25mm or over to and excel.40mm ±0.15mm 40mm or over to and excel.50mm ±0.18mm 50mm or over to and excel.60mm ±0.20mm 60mm or over to and excel.70mm ±0.23mm 70mm or over to and excel.80mm ±0.25mm 80mm or over to and excel.90mm ±0.30mm 90mm or over to and excel.100mm ±0.40mm 100mm or over ±0.50% Note:1. For hot finished seamless steel tube, the outside diameter tolerance No.1 shall be applied. 2.The tolerance on outside diameter of quenched and tempered tubes shall be as agreed upon by the purchaser and manufacturer.   Tolerances on WT Division Tolerance on WT No.1 under 4mm +0.6mm -0.5mm 4mm or over +15%-12.5% No.2 under 3mm ±0.3mm 3mm or over ±10% No.3 under 2mm ±0.15mm 2mm or over ±8% Note: For the fiished seamless steel tubes the tolerances No.1 shall be applied. The tolerances on the tube length shall be in the range of 0to+50mm.However,when tolerances outside this range are especially required,agreement shall be made between the purchaser and manufacturer.