执行标准Standard材料类别Material Type & Grade公称尺寸Normal Size (in.)长度Length螺纹Screw Thread机械性能 Mechanical Requirementσb(MPa)σ0.2(MPa)δ4(%)ψ(%)硬度HardnessASME/ANSI B 16.5ASME/ANSI B 18.2.1ASME/ANSI B 1.1A 193B7≤2.5按合同规定According to order粗牙，8牙系列螺纹精度2A级UNC, 8UNAccuracy of thread Grade 2A≥860≥7251650≤HB321B7M≤2.5≥690≥55018≤HB235B16≤2.5≥860≥725≤HB321B8/B8M/B8C/B8T (CL. 1)所有直径All diameters≥515≥2053050≤HB223B8/B8C/B8T(CL. 2)≤0.75≥860≥6901235≤HB321＞0.75~1≥795≥55015＞1~1.25≥725≥45020＞1.25~1.5≥690≥3452845B8M (CL. 2)≤0.75≥760≥6551545＞0.75~1≥690≥55020＞1~1.25≥655≥45025＞1.25~1.5≥620≥34530A 453660 B所有直径All diameters≥895≥5851518HB248~341执行标准Standard材料类别Material Type & Grade公称尺寸Normal Size (in.)长度Length螺纹Screw Thread机械性能 Mechanical Requirementσb(MPa)σ0.2(MPa)δ4(%)ψ(%)硬度HardnessASME/ANSI B 16.5ASME/ANSI B 18.2.1ASME/ANSI B 1.1A 320L7≤2.5按合同规定According to order粗牙，8牙系列螺纹精度2A级UNC, 8UNAccuracy of thread Grade 2A≥860≥7251650——B8/B8M/B8C/B8T (CL. 1)所有直径All diameters≥515≥2053050≤HB223B8/B8C/B8T (CL. 2)≤0.75≥860≥6901235≤HB321＞0.75~1≥795≥5501530＞1~1.25≥725≥4502035＞1.25~1.5≥690≥3452845B8M (CL. 2)≤0.75≥760≥6551545＞0.75~1≥690≥55020＞1~1.25≥655≥45025＞1.25~1.5≥620≥34530