Technical standards and specifications EN ISO 4017
The international standard EN ISO 4017 defines strict technical requirements for hexagon head screws with full metric threads. The nomenclature includes products with a nominal thread diameter from M1.6 to M64. Design and tolerances are regulated depending on the accuracy class: class A is applied to screws with threads from M1.6 to M24 with a shank length of up to 10d or 150 mm, while class B is used for fasteners with threads larger than M24 or when the specified length limits are exceeded.
EV Group China engineers point out that these screws are structurally identical to products under ISO 4014, but are distinguished by the presence of a full thread along the entire length of the shank. Standard commercial product ranges are usually limited to a nominal length of 200 mm.
When designing assemblies and mechanisms that require specific characteristics other than the basic parameters of EN ISO 4017, it is necessary to be guided by related ISO standards, including requirements for basic dimensions (ISO 724), tolerance fields (ISO 965-1), mechanical properties under static loads (ISO 898-1), and corrosion-resistant steels (ISO 3506-1). EV Group China provides supplies of fasteners that fully comply with current international specifications.