We stock a comprehensive range of bolting products including hex bolts to DIN 931, hex setscrews to DIN 933, coach bolts to DIN 603, and hex flange bolts to DIN 6921. All are available in high tensile steel grades 8.8, 10.9 and 12.9, stainless steel A2 and A4, and zinc plated mild steel. Sizes range from M4 to M48 depending on type, with larger diameters available to order.
What is the difference between a hex bolt (DIN 931) and a hex setscrew (DIN 933)?
A DIN 931 hex bolt has a plain unthreaded shank below the head, with threading only on part of the length. A DIN 933 hex setscrew is fully threaded from head to tip. Bolts are typically used with a clearance hole, while setscrews provide full thread engagement through the joint.
What steel grades are available for hex bolts?
We stock hex bolts in grade 8.8 (standard high tensile), grade 10.9 (higher strength), and grade 12.9 (the highest standard grade). Grade 8.8 is suitable for most general engineering applications. Grades 10.9 and 12.9 are used where higher clamping forces are required, such as in structural steelwork and heavy machinery.
When should I use a coach bolt instead of a hex bolt?
Coach bolts (DIN 603) have a domed head with a square shank beneath it that grips into the material to prevent rotation. They are used where you need to tighten from one side only, particularly in timber-to-steel and timber-to-timber connections. The smooth dome head also provides a tamper-resistant finish.
