BS A 312:1997 强度级小于或等于1100MPa的涂层或未涂层金属材料制阶梯形杆、短长度或中等长度MJ螺纹的内偏移十字形肋状或非肋状驱动的平头螺钉.尺寸
Screws, pan head, internal offset cruciform ribbed or unribbed drive, stepped shank, short or medium length MJ threads, metallic material, coated or uncoated, strength classes less than or equal to 1100 MPa - Dimensions
This International Standard specifies the dimensions of pan head screws with internal offset cruciform ribbed or unribbed drive, stepped shank, short or me-dium length MJ threads, ...