BS 4439 specifies the dimensions and tolerances for screwed studs with ISO metric threads in diameters from 3 mm to 39 mm inclusive, intended for general purposes. Mechanical properties are given only in respect of carbon or alloy steel screwed studs which are not to be used for special applications, such as those requiring weldability or corrosion resistance. BS 4439 applies to non-ferrous and stainless-steel screwed studs.
BS 4439 on screwed studs is useful for:
Studs prevent leakage of fluids through holes in machines. They are also used in the assembling of heavy materials such as turbines, tanks, cylindrical heads, gaskets, etc. For the proper functioning of screwed studs, they need to comply with quality standards.
BS 4439 provides you with standard nominal lengths and tolerances on the standard nominal lengths of screwed studs. The manufacturers need to adhere to specifications provided in BS 4439 and take the necessary steps to ensure that the requirements given in BS 4439 are fulfilled.
BS 4439 covers marking and identification requirements. The strength grade marking requirement in BS 4439 is only mandatory for steel screwed studs of 12 mm diameter and larger manufactured to strength grade designation 8.8 or higher. BS 4439 guidelines help you to manufacture and supply high-quality screwed studs with no manufacturing defects to your customers. These customers will be able to use screwed studs safely.
ISO 898-1
Technically equivalent to:ISO 888