Buy Hex Set Bolts Online in Australia
Hex Set Bolt Selection — Quick Reference (Partially-Threaded)
Hex set bolts = HIGH-TENSILE PARTIALLY-THREADED hex bolts. Smooth shank section + threaded section. Shear loads + structural + machinery applications where smooth shank provides bearing surface.
| Hex Set Bolt Type | Best For |
|---|---|
| Class 8.8 Hex Set Bolt | Workshop standard partially-threaded |
| Class 10.9 Hex Set Bolt | Higher-strength + machinery |
| Class 12.9 Hex Set Bolt | Critical applications |
| 304 / 316 Stainless | Corrosion + marine |
| Hot-Dip Galvanised | Outdoor + extended corrosion |
| Zinc-Plated | Indoor general |
| Common Sizes (M5-M30+) | Engineering range |
| Various Lengths | Match to grip + shear plane |
Critical: Set bolts = partially threaded (vs fully-threaded hex bolts). SMOOTH SHANK provides bearing surface for shear loads. Match grade + finish to mating nut + application. Match thread engagement to joint design. Brands: Bremick, Hobson, Inox World. Companion: hex bolts, hex bolts + nuts, fasteners.
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.
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See our full fasteners range including hex bolts and nuts, hex head flanged bolts, and coupling nuts.
People Also Ask — Hex Set Bolts
Q: Why does a partially-threaded hex set bolt provide more shear capacity than a fully-threaded bolt of the same size?
The smooth shank, not the thread, occupies the shear plane in the joint, giving full cross-section shear capacity — thread sitting in the shear plane instead reduces the effective shear area by up to 40%.
Q: What happens if a Grade 8.8 hex set bolt is paired with an under-grade nut?
An under-grade nut will strip before the bolt reaches its proof load, undermining the joint design — the nut grade must always match or exceed the bolt grade.
Q: What torque standard applies when installing structural hex set bolts?
AS 4100 or the project specification sets the minimum installation torque, applied with a calibrated torque wrench — hand-tightening gives insufficient and unverifiable preload for a structural connection.
Q: What does the hot-dip galvanised coating on hex set bolts need to meet for outdoor structural use?
AS/NZS 4680 for structural hot-dip galvanised fasteners, which specifies an 80+ micron zinc coating.
Q: When would an extended-length hex set bolt be needed over a standard length?
For through-fastening thick steel sections, timber-and-steel composite connections, and machinery baseplate applications — hex set bolts are available up to 300mm and longer on special order.