Hex head bolts and setscrews are a primary method of fastening used across construction and engineering.
While they look similar, the primary difference is their threading: Setscrews (DIN 933) are fully threaded to the head, making them ideal for pre-tapped holes.
Hex Bolts (DIN 931) however have a partially threaded shank that provides a smooth bearing surface for high-vibration assemblies.
Popular Materials and Standards
- High Tensile Steel: The standard for structural and automotive work, typically finished in Bright Zinc Plating (BZP) for indoor corrosion resistance or Galvanised for use outdoors. Available in various tensile strengths.
- A2 Stainless Steel (304): Best for general outdoor and architectural use due to its rust resistance.
- A4 Marine Grade Stainless Steel (316): Essential for saltwater, chemical, or pool environments to prevent pitting and staining.
- Brass: Essential for applications where corrosion resistance, electrical conductivity, or a decorative finish is required. Because brass is a non-magnetic alloy, these fasteners are frequently used in marine environments, electrical installations, and heritage restoration projects.