GB/T 3098.21-2008 in English

《GB/T 3098.21-2008紧固件机械性能 第21部分：不锈钢自攻螺钉》由TC85（全国紧固件标准化技术委员会）归口，主管部门为中国机械工业联合会。
本部分是国家标准“紧固件机械性能”系列标准之一。本部分是ＧＢ／Ｔ３０９８的第２１部分。 本部分规定了由奥氏体、马氏体和铁素体耐腐蚀不锈钢制造的、在环境温度为１５ ℃～２５ ℃条件下进行试验时，自攻螺钉的机械性能。在较高或较低温度下，其性能可能不同。
本部分适用于ＧＢ／Ｔ５２８０规定的螺纹为ＳＴ２．２～ＳＴ８的自攻螺钉。
本部分不适用于有特殊要求，如可焊接性的自攻螺钉。

Scope

This standard specifies the mechanical properties of self-tapping screws made of austenitic, martensitic and ferritic corrosion-resistant stainless steels when tested at an ambient temperature of 15 °C to 25 °C. Performance may vary at higher or lower temperatures. This Part is applicable to self-tapping screws whose threads are ST 2.2～ST 8 specified in GB/T 5280. This section does not apply to self-tapping screws that have special requirements, such as welding. This part does not specify corrosion resistance and oxidation resistance in special environments, but some information on materials used in special environments is given in Appendix D. See ISO 8044 for definitions of corrosion and corrosion resistance. This part of ISO 10000 classifies the performance of corrosion-resistant stainless steel fasteners under specified conditions. Corrosion resistance, oxidation resistance, and mechanical properties at high temperatures or below zero must be negotiated between the user and the manufacturer for each special occasion. Appendix C gives the influence of carbon content on intergranular corrosion under high temperature conditions. Usually austenitic stainless steel fasteners are non-magnetic in the annealed state, and some magnetism may be obvious after cold working.