Mechanical Properties of Fasteners
2011-02-23 Author:De-Li Chang Class:CFW
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℃ to 35℃.
Fasteners1) conforming to the requirements of this standard are evaluated at that ambient temperature range.They may not retain the specified mechanical and physical properties at elevated temperatures (see information in Annex B) and/or lower temperatures.
NOTE 1 Fasteners conforming to the requirements of this standard have been used in applications ranging from –50°C to +150°C. Users should 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 to determine 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 instance in EN 10269, ASTM F2281 and in ASTM A320.
Certain fasteners may not fulfil the tensile or torsional requirements of this standard because of the geometry of the head which reduces the shear area in the head as compared to the stress area in the thread such as fasteners with low head, with or without external driving feature, low round or cylindrical head with internal driving feature or countersunk head with internal driving feature (see 8.2).