Hex Set Bolts

Hex Set Bolts — High-Tensile Partially-Threaded Hex Bolts

Hex set bolts (DIN 931 partially threaded hex bolts) have an unthreaded shank below the hex head that provides a precision location surface in the joint — the shank fits the bolt hole in bearing contact for shear-loaded connections. AIMS Industrial sells hex set bolts in metric Grade 8.8 and Grade 10.9 zinc-plated and hot-dip galvanised for structural steel connections, machinery frames, and high-load fastening applications.

Hex Set Bolts We Stock

• Grade 8.8 Hex Set Bolts (DIN 931): Standard Grade 8.8 partially threaded hex bolts in metric sizes M8 to M36 — the workhorse structural bolt for Australian construction and machinery. Zinc-plated for protected structural applications; hot-dip galvanised for outdoor and corrosive environments.
• Grade 10.9 Hex Set Bolts: High-tensile Grade 10.9 partially threaded hex bolts for high-strength structural connections where Grade 8.8 is insufficient — mining equipment, heavy machinery frames, and high-load structural connections.
• Hot-Dip Galvanised Hex Set Bolts: HDG partially threaded hex bolts and matching nuts for structural steel in outdoor, marine, and mining environments. HDG provides 80+ micron zinc coating — meeting AS/NZS 4680 for structural hot-dip galvanised fasteners.
• Long Length Availability: Hex set bolts available in extended lengths (up to 300mm and longer for special orders) for through-fastening of thick steel sections, timber and steel composite connections, and machinery baseplate applications.

Hex Set Bolt Application Guide

• Shank vs Thread in the Shear Plane: The primary advantage of a partially threaded bolt over a fully threaded screw is that the shank (not thread) occupies the shear plane in a bolted joint — providing full cross-section shear capacity. Thread in the shear plane reduces effective shear area by up to 40%. Specify DIN 931 partially threaded bolts for shear-loaded connections.
• Matching the Nut to Bolt Grade: Grade 8.8 bolts require minimum Grade 8 nuts; Grade 10.9 bolts require minimum Grade 10 nuts. Under-grade nuts will strip before the bolt reaches proof load — undermining the joint design. Always confirm matching nut and bolt grades.
• Torquing to Specification: Structural hex set bolts should be torqued to the minimum installation torque per AS 4100 or the project specification. Use a calibrated torque wrench — hand-tightening provides insufficient and unverifiable preload for structural connections.

Australian Business, Local Supply: As a proudly Australian business since 1988, we stock locally and work with trusted local Australian manufacturers and distributors to ensure fast, reliable supply.

Expert Support: Need help buying the right product for your application? Contact our team for application-specific advice or request a quote.

See our full fasteners range including hex bolts and nuts, hex head flanged bolts, and coupling nuts.