M16 Bolts

M16 Bolts — the Structural Standard for Heavy Engineering and Construction

M16 bolts are the benchmark fastener for heavy structural steel connections in Australia. With a 16 mm nominal diameter and standard coarse pitch of 2.0 mm, M16 provides the clamping force required for primary structural connections, heavy machinery bases, large anchor assemblies, and high-load civil and construction applications. AS 4100 (Steel Structures) specifies M16, M20, and M24 as the standard bolt sizes for structural steel connections — M16 is the smallest of the structural grades and the most commonly used for secondary members, purlins, and general connections. AIMS Industrial stocks M16 bolts in commercial and structural grades, stainless steel, and galvanised, dispatched from Sydney.

Types of M16 Bolts

M16 hex head bolts (AS 1111.1 / ISO 4014/4017, 24 mm across flats) are the standard for general mechanical and structural bolting. M16 structural bolts conforming to AS/NZS 1252 are high-strength bolts used in fully-tensioned structural steel connections — these have specific head marking requirements and must be used with AS/NZS 1252 nuts and washers. M16 socket cap screws (ISO 4762, 14 mm hex key) are used in heavy machine building and tooling. M16 anchor bolts, including cast-in, sleeve anchors, and chemset threaded rod, are used to secure columns, machinery, and structural posts into concrete foundations. M16 through bolts (rawl bolts / sleeve anchors) are the most common concrete fastener at this size. M16 eye bolts are used for lifting and rigging with specific rated WLL values. M16 stainless steel bolts are used in coastal infrastructure, marine, and food-grade plant.

Grades and Materials

Grade 8.8 M16 bolts (800 MPa tensile, 640 MPa yield, zinc-plated) are the standard commercial specification. AS/NZS 1252 Grade 8.8S structural bolts are used for fully-tensioned connections in structural steel per AS 4100 — these are not interchangeable with commercial Grade 8.8 where fully-tensioned installation is specified. Grade 10.9 M16 bolts are used in high-strength machinery applications. M16 stainless steel bolts in A2-70 (304) and A4-80 (316) are specified for corrosive, marine, and outdoor structural applications. Hot-dip galvanised M16 bolts per AS/NZS 4680 provide long-term protection for exposed infrastructure including bridges, walkways, and outdoor structures. M16 structural anchor bolts are typically supplied in Grade 4.6 or 8.8, threaded rod, or L-bolt forms for embedding in concrete.

Dimensions and Thread Specifications

M16 coarse pitch: 2.0 mm; fine pitch M16×1.5 is available for specific mechanical applications. Hex head across-flats: 24 mm. Socket cap screw hex key: 14 mm. Standard stock lengths: 20 mm to 400 mm for hex bolts. For anchor bolts, embedment depth is specified by the structural engineer or anchor manufacturer based on design loads. Tightening torque for Grade 8.8 M16 (dry): approximately 225 N·m; structural bolt tightening per AS 4100 requires specific procedures (turn-of-nut, direct tension indicator, or torque control).

Applications

M16 structural bolts are the core fastener in Australian steel construction — portal frame buildings, industrial sheds, mezzanines, walkways, bridges, and heavy civil infrastructure. In machinery and plant, M16 is used for equipment bases, gearbox and motor mounting, heavy conveyor structures, crane rails, and heavy transport frames. M16 anchor bolts are specified whenever heavy plant, structural columns, or machinery must be positively anchored to a concrete foundation. M16 stainless bolts are used in marine structures, jetties, coastal walkways, food and dairy processing equipment, and outdoor public infrastructure.

Selecting the Right M16 Bolt

For most non-structural applications, Grade 8.8 commercial M16 hex bolts with a matching full nut and washer are appropriate. For structural steel connections per AS 4100, confirm whether snug-tight or fully-tensioned installation is required — only AS/NZS 1252 compliant bolts, nuts, and washers may be used for fully-tensioned work. For anchor bolt applications, always obtain the technical datasheet and ensure the anchor is rated for your design loads including seismic where applicable. For outdoor or marine service, specify galvanised or A4 stainless. The AIMS team can assist with structural and mechanical bolt specification for any project.

AIMS Industrial supplies M16 bolts in Grade 8.8 commercial, AS/NZS 1252 structural, Grade 10.9, 304 and 316 stainless steel, and hot-dip galvanised, in a comprehensive range of lengths. Contact our Sydney team for trade pricing, project quantities, and Australia-wide delivery.