ISO 898
ISO 898 is an international standard that defines mechanical and physical properties for ISO [metric screw thread|metric fasteners]. This standard is the origin for other standards that define properties for similar metric fasteners, such as SAE J1199 and ASTM F568M. It is divided into five parts:
1. Bolts, screws and studs with specified property classes - Coarse thread and fine pitch thread
2. Nuts with specified proof load values - Coarse thread
3. Flat washers with specified property classes
5. Set screws and similar threaded fasteners not under tensile stresses
6. Nuts with specified proof load values - Fine pitch thread
7. Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm
With exception to part 7, which defines test standards, the parts of this standard define properties for fasteners made of carbon steel and alloy steel. The standards define that the testing must be performed at ambient temperatures, which is defined as between. The standards do not cover fasteners that would otherwise apply but require special properties, such as weldability or corrosion resistance.
Part 1: Bolts, screws and studs with specified property classes – Coarse thread and fine pitch thread
Part 1 defines the mechanical properties of bolts, screws, and studs. It specifically applies to fasteners that have an ISO metric screw thread as defined in ISO 68-1. The properties are defined for M1.6-39 with coarse threads and M8-39 with fine threads. The diameter and pitch combinations must adhere to ISO 261 and ISO 262 and the thread tolerances must adhere to ISO 965 parts 1, 2, and 4.Part 1 does not specify properties for fasteners that have head geometries that reduce the shear strength of the fastener, such as low head screws and countersunk heads. It also excludes set screws, which are covered under part 5.