Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs with specified property classes — Coarse thread and fine pitch thread
This part of ISO 898 specifies mechanical and physical properties of bolts, screws and studs made of carbon steel and alloy steel when tested at an ambient temperature range of 10 °C to 35 °C. Fasteners — the term used when bolts, screws and studs are considered all together — that conform to the requirements of this part of ISO 898 are evaluated at that ambient temperature range. They might not retain the specified mechanical and physical properties at elevated temperatures (see Annex B) and/or lower temperatures.
Certain fasteners might not fulfill the tensile or torsional requirements of this part of ISO 898-1 because the geometry of their heads reduces the shear area in the head compared to the stress area in the thread. These include fasteners having a low head, with or without external driving feature, a low round or cylindrical head with internal driving feature or a countersunk head with internal driving feature (see 8.2).