Structural K0 Bolts & Nuts

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Match your spanner / socket AF (across-flats) to the size it fits - our reference chart covers every metric and imperial size we stock.
K0 structural bolt sets are preassembled high-tensile bolt, nut and washer combinations used in building and construction to fasten steel-to-steel structural connections. They are supplied to AS1252:2016 K0 — the Australian standard for High Strength Friction Grip (HSFG) bolting.
Each set ships as a matched assembly: one Class 8.8 hot-dip galvanised hex bolt, one matching K0 hex nut, and the required structural flat washer(s). The K0 marking on the bolt head and the 3-dimple mark on the washer indicate compliance.
MATERIALS AND GRADES
Hot-Dip Galvanised Class 8.8 — The only material stocked. AS1252:2016 mandates HDG finish on K0 structural assemblies for corrosion resistance during construction and service.
Sizes: M12 through M36 metric coarse, with M30 and M20 the busiest sizes.
Thread system: Metric Coarse — Right Hand.
Standard: AS1252:2016 K0.
K0 sets are HSFG bolts and must be tightened to the correct preload as specified by the engineer. Refer to our Technical PDF's Library for K0 tightening torques and bolt tension data. Improperly preloaded HSFG bolts will not develop the friction grip joint design relies on.
WHY AUSTRALIA TRUSTS BOLT & NUT
With 15+ years selling fasteners online from Brisbane, we hold over 25,000 stock lines and 200 million pieces — 98.75% of online orders placed before 1pm leave same day. Save more as you buy more — we offer up to 13 price breaks plus 3 spend-tier discounts. Read our customer reviews or get in touch if you need help picking the right bolt.
Preassembled high-tensile bolt, nut and washer sets to AS1252:2016 K0 for structural steelwork. Class 8.8 hot-dip galvanised, M12 to M36.
TECHNICAL RESOURCES
Key charts and specification sheets: Imperial vs Metric Strength Chart
For the full library, see our Technical PDF's Library.


