This standard specifies tolerance limits for various surface defects of generally required bolts, screws and studs. This standard applies to the following bolts, screws and studs:
——Nominal diameter of one screw 5 mm or more - Part class A and B - Strength class 10.9 or less (If there is no stipulation in the screw parts standard or if there is no agreement between the delivery and delivery parties) 1.2 Special requirements (for example, for automatic assembly) The tolerance limits for surface defects on bolts, screws and studs are specified in JIS B1043. If it is necessary to more strictly control the surface defects of bolts, screws, and studs due to technical requirements for use, it is better to specify this in the respective threaded component standards. Specify tolerance limits in purchase specifications and purchase orders. 1.3 Even if surface defects are within the tolerance limits shown in 3. (Types, causes, appearance and limits of surface defects), the requirements for minimum mechanical properties specified in ISO 898-1 shall be met. Reference: The provisions of ISO 898-1 are equivalent to JIS B 1051 (mechanical properties of steel bolts and machine screws). Notes 1. The diagram shown in 3. is an example only. The same applies to other types of bolts, screws and studs. 2. Some individual figures may be exaggerated to make surface defects clearer.
JIS B 1041:1993 history
1993JIS B 1041:1993 Fasteners -- Surface discontinuities -- Part 1: Bolts, screws and studs for general requirements