JIS B 0209-4:2001 ISO general purpose metric screw threads -- Tolerances -- Part 4: Limits of sizes for hot-dip galvanized external screw threads to mate with internal screw threads tapped with tolerance position H or G after galvanizing
This standard specifies the dimensional tolerances and allowable limit dimensions for the effective diameter and crest diameter (external diameter of the male thread) of general-use metric male threads specified in JIS B 0205-3. Note that the general metric male thread specified in JIS B 0205-3 has a standard chevron shape in accordance with JIS B 0205-1. External threads according to this standard are intended to be combined with internal threads tapped in tolerance position H or G after hot-dip galvanizing. The allowable limit dimensions for the fit categories shown in this standard are derived from the tolerances specified in JIS B 0209-1, and the underlying dimensional tolerances are based on the following formula. esaz=one(300+20P) Here, the unit of es is expressed in μm, and the unit of P is expressed in mm. Products manufactured with thread tolerances according to this standard may fail at loads lower than the minimum tensile load specified in JIS B 1051 due to a reduction in effective cross-sectional area. External threads with thread tolerances in accordance with this standard shall not be combined with internal threads with thread tolerances in accordance with JIS B 0209-5 because this may pose a serious risk of thread shearing. . Notes 1. If the male thread is not specified with tolerance class 6az, and the product has been processed in a centrifuge, it must be combined with a female thread with tolerance class 6AZ, and if the product has not been processed in a centrifuge. If not, combine with hot-dip galvanized female threads of tolerance class 6AX. Note: The corresponding international standards for this standard are shown below. The symbols representing the degree of correspondence are IDT (matched), MOD (modified), and NEQ (not equivalent) based on ISO/IEC Guide 21.
JIS B 0209-4:2001 history
2001JIS B 0209-4:2001 ISO general purpose metric screw threads -- Tolerances -- Part 4: Limits of sizes for hot-dip galvanized external screw threads to mate with internal screw threads tapped with tolerance position H or G after galvanizing