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
|Publication Date:||1 April 2009|
|ICS Code (Bolts, screws, studs):||21.060.10|
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.
NOTE 1 Fasteners conforming to the requirements of this part of ISO 898 are used in applications ranging from −50 °C to +150 °C. Users are advised to consult an experienced fastener metallurgist for temperatures outside the range of −50 °C to +150 °C and up to a maximum temperature of +300 °C when determining appropriate choices for a given application.
NOTE 2 Information for the selection and application of steels for use at lower and elevated temperatures is given, for example, in EN 10269, ASTM F2281 and in ASTM A 320/A 320M.
Certain fasteners might not fulfil 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).
This part of ISO 898 is applicable to bolts, screws and studs
made of carbon steel or alloy steel,
having triangular ISO metric screw thread according to ISO 68-1,
with coarse pitch thread M1,6 to M39, and fine pitch thread M8×1 to M39×3,
with diameter/pitch combinations according to ISO 261 and ISO 262,
having thread tolerances according to ISO 965-1, ISO 965-2 and ISO 965-4.
It is not applicable to set screws and similar threaded fasteners not under tensile stresses (see ISO 898-5).
It does not specify requirements for such properties as
- corrosion resistance,
- resistance to shear stress,
- torque/clamp force performance, or
- fatigue resistance.