Technical specifications and scope of application for EN ISO 4018 screws
The international standard EN ISO 4018 regulates the parameters of hexagon head screws with product grade C. This type of fastener is designed for use in metal structures and mechanical engineering where larger tolerances are acceptable. The range of nominal thread diameters covers sizes from M5 to M64 inclusive.
Engineers at EV Group China draw attention to a structural feature: unlike the ISO 4016 standard, this standard assumes the thread is cut directly up to the screw head, which is critical to consider when selecting fasteners for assemblies subject to dynamic loads.
When designing connections with non-standard operational requirements, EV Group China specialists recommend referring to the current list of related international standards to select optimal parameters:
- ISO 724: Basic dimensions for metric threads.
- ISO 888: Bolts and screws – Nominal lengths, and thread lengths for general purpose bolts.
- ISO 898-1: Mechanical properties of fasteners made of carbon steel and alloy steel.
- ISO 965-1: General purpose metric screw threads – Tolerances.
- ISO 4759-1: Tolerances for fasteners (bolts, screws, studs and nuts).