scope:

This part of ISO 3506 specifies the mechanical properties of bolts, screws and studs made of corrosionresistant stainless steels, when tested at an ambient temperature range of 10 °C to 35 °C. It specifies property classes in relation to austenitic, martensitic, ferritic and duplex (austenitic-ferritic) steel grades for fasteners (the term "fasteners" is used when bolts, screws and studs are considered all together). ISO 3506-6 provides additional technical information on suitable stainless steels and their properties. Fasteners conforming to the requirements of this standard are evaluated at that ambient temperature range. It is possible that they do not retain the specified mechanical and physical properties at elevated and/or lower temperatures. NOTE 1 - Fasteners conforming to the requirements of this standard are used in applications ranging from - 40 °C to + 150 °C. For application outside this range and up to a temperature range of - 196 °C to + 300 °C, see Annex A and ISO 3506-6. It is the responsibility of the user to determine the appropriate choice for a given application, and consulting an experienced fastener metallurgist is recommended for temperatures outside this range. However, several factors need to be taken into account, e.g. stainless steel composition, time of exposure at elevated or low temperature, the effect of the temperature on the fasteners mechanical properties and clamped parts, and the corrosive service environment of the bolted joint. NOTE 2 - It is intended to develop ISO 3506-52) in order to assist in the selection of appropriate stainless steel grades and property classes intended for use at high temperatures up to + 800 °C. This part of ISO 3506 applies to bolts, screws and studs: - with ISO metric screw thread in accordance with ISO 68-1, - with coarse pitch thread M1,6 to M39, and fine pitch thread M8 × 1 to M39 × 3, - with diameter/pitch combinations in accordance with ISO 261 and ISO 262, - with thread tolerances in accordance with ISO 965-1 and ISO 965-2, - with specified property classes, and - of any shape. NOTE 3 - The designation system of this standard can be used for sizes outside the limits given in this clause (e.g. d > 39 mm), provided that all applicable mechanical and physical requirements of the property classes are met. Certain bolts, screws and studs might not fulfil the tensile or torsional requirements of this standard because of the geometry of their head or unthreaded shank, thus resulting in reduced loadability (e.g. when shear area in the head is less than the stress area in the thread, see 8.2.2).