Hex Head Screws

Hex Head Screw Selection — Quick Reference (Metric Cap Screws)

Hex head screws — METRIC fully-threaded HEX CAP SCREWS — workshop + machinery + structural fastening. Threaded full length vs hex SET BOLT (partially threaded). External hex drive + standard fasteners.

Critical: FULLY-THREADED hex cap screw vs PARTIALLY-THREADED hex set bolt — different applications. Match grade + finish to mating nut + application. See torque chart. Brands: Bremick, Hobson, Inox World. Companion: hex bolts, hex bolts + nuts, fasteners.

Hex Head Screws — Metric Fully-Threaded Hex Cap Screws

Hex head screws (fully-threaded hex cap screws, DIN 933) are fully threaded from head to end — providing thread engagement through the full fastening depth. AIMS Industrial sells hex head screws in metric Grade 8.8 zinc-plated and 316 stainless steel from M4 to M24 for machinery assembly, panel fastening, and structural applications where full thread engagement is required.

Hex Head Screws We Stock

• Grade 8.8 Zinc-Plated Hex Head Screws: Metric Grade 8.8 fully-threaded hex head screws (DIN 933) — the standard metric hex screw for machinery, equipment, and structural assembly. Zinc plating provides corrosion resistance for indoor and protected applications. Available M4 to M24 in standard lengths.
• Grade 10.9 Hex Head Screws: High-strength Grade 10.9 fully-threaded hex head screws for high-load fastening applications where Grade 8.8 is insufficient. Black oxide or zinc-plated finish. Tensile strength 1,040 MPa.
• 316 Stainless Steel Hex Head Screws: 316 ss fully-threaded hex head screws for corrosive environments — food processing, marine, chemical plant, and pharmaceutical applications. Matching stainless nuts and washers required.
• DIN 933 vs DIN 931: DIN 933 = fully threaded (thread to head). DIN 931 = partially threaded (unthreaded shank). Hex head screws (DIN 933) are selected where full thread engagement with the tapped hole or nut is required; partially threaded bolts (DIN 931) are used where the shank provides a precision location in the joint.

Hex Head Screw Selection Guide

• Full Thread vs Partial Thread: Use fully-threaded hex head screws (DIN 933) where the fastener threads into a tapped hole or nut across the full fastened length. Use partially-threaded hex bolts (DIN 931) for shear-loaded joints where the shank (not the thread) carries the shear load — particularly structural steel connections.
• Thread Pitch: Metric hex head screws have coarse thread as standard (e.g., M10 × 1.5). Fine pitch variants are available for high-vibration applications where greater thread contact provides better vibration resistance. Confirm thread pitch against the tapped hole or nut specification.
• Grade Marking: Grade 8.8 bolts are marked with "8.8" on the hex head face; Grade 10.9 with "10.9". Never use unmarked or uncertain-grade bolts in structural or safety-critical joints — the grade marking is mandatory per Australian Standards.

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 hex set bolts.

People Also Ask — Hex Head Screws

Q: Why does a hex head screw need to be fully threaded for structural fastening applications?

A hex head screw (fully-threaded, DIN 933) is threaded from head to end so the full length engages when it's driven into a tapped hole or through a nut — this is what's needed where full thread engagement is required across the fastened depth. A partially-threaded hex set bolt (DIN 931) leaves a smooth shank instead, which is used where the shank needs to locate precisely or carry shear load rather than maximise thread engagement.

Q: Do I need a matching grade nut and washer with a high-tensile hex head screw?

Yes, particularly with 316 stainless steel hex head screws used in corrosive environments — matching stainless nuts and washers are required so the whole fastening assembly performs and corrodes consistently, rather than pairing a high-grade screw with a mismatched nut or washer.

Q: What thread pitch should I use for a vibration-prone application?

Metric hex head screws come with coarse thread as standard, but fine-pitch variants are available specifically for high-vibration applications — the finer thread gives greater thread contact, which provides better vibration resistance than the standard coarse pitch.