Buy Coupling Nuts Online in Australia
Coupling Nut Sizes — Quick Reference
Coupling nuts (joiner nuts) join two lengths of threaded rod end-to-end or extend bolt length. Standard component in hanging systems, HVAC brackets, cable management supports and structural threaded rod assemblies. AIMS stocks metric coupling nuts M6-M24 in zinc-plated, hot-dip galvanised and 316 stainless steel.
| Nominal Size | Length (Across) | AF (Across Flats) | Common Use |
|---|---|---|---|
| M6 | 18 mm | 10 mm | Light hanging, electrical conduit, small HVAC |
| M8 | 24 mm | 13 mm | General hanging systems, sprinkler droppers |
| M10 | 30 mm | 17 mm | HVAC ductwork support — standard for medium loads |
| M12 | 36 mm | 19 mm | Larger ductwork, structural threaded rod connections |
| M16 | 48 mm | 24 mm | Heavy hanging systems, large equipment support |
| M20 | 60 mm | 30 mm | Heavy industrial mounting, large machinery |
| M24 | 72 mm | 36 mm | Very heavy structural connections |
Finish selection: Zinc-plated (indoor, light outdoor); Hot-dip galvanised (outdoor, exposed); 316 stainless (marine, food, chemical). Always match the THREAD GRADE of the coupling nut to the threaded rod — Class 8.8 nuts with Class 8.8 rod. Companion ranges: threaded rod, hex bolts & nuts, structural bolts.
Coupling Nuts — Threaded Rod Connectors & Joiner Nuts
Coupling nuts (connector nuts or joiner nuts) join two lengths of threaded rod end-to-end, extend bolt lengths, or connect turnbuckle-style assemblies — a standard component in hanging systems, cable management supports, HVAC brackets, and structural threaded rod assemblies. AIMS Industrial sells coupling nuts in metric zinc-plated, hot-dip galvanised, and 316 stainless steel from M6 to M24.
Coupling Nuts We Stock
- Zinc-Plated Coupling Nuts: Metric zinc-plated hex coupling nuts for indoor and protected threaded rod jointing — covering M6 to M24 for HVAC duct hanging, pipe supports, suspended ceiling systems, and equipment mounting applications.
- Hot-Dip Galvanised Coupling Nuts: HDG coupling nuts for outdoor and industrial structural applications — matching galvanised threaded rod in pipe support, cable tray hanging, and structural steel bracket systems where long-term corrosion resistance is required.
- 316 Stainless Steel Coupling Nuts: Stainless steel coupling nuts for food processing, pharmaceutical, and marine hanging and support systems. Always use matching stainless threaded rod with stainless coupling nuts to prevent galvanic corrosion.
- Metric Range M6 to M24: Coupling nuts available from M6 (light fixture and service supports) through M12 (standard HVAC and pipe supports) to M24 (heavy structural and industrial applications).
Coupling Nut Application Guide
- Threaded Rod Extension: Coupling nuts connect two lengths of threaded rod to achieve a required overall length — useful where stock lengths are shorter than needed, or where on-site length adjustment is required during installation.
- Thread Engagement: The coupling nut should engage both threaded rod ends by a minimum of 1× the rod diameter — insufficient thread engagement reduces joint strength. Mark the centre of the coupling nut before installation to ensure equal thread engagement on both ends.
- Material Matching: Use the same material (zinc-plated, galvanised, or stainless) for coupling nuts, threaded rod, and washers/nuts throughout a hanging or support assembly. Mixed materials create differential corrosion that can lead to premature joint failure in the service environment.
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.
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