M14 Bolts

M14 Bolts — Heavy-Duty Metric Fasteners for Demanding Applications

M14 bolts occupy a practical but sometimes overlooked position in the metric fastener range — larger than M12 but not as heavy as M16, they provide a significant step up in clamping force for applications where M12 is marginal and M16 is more than required. With a 14 mm nominal diameter and standard coarse pitch of 2.0 mm, M14 bolts are commonly found in heavy agricultural machinery, earthmoving equipment, industrial gearboxes, heavy transport, and structural connections in steel fabrication. AIMS Industrial stocks M14 bolts in Grade 8.8 and stainless steel with fast dispatch from Sydney.

Types of M14 Bolts

M14 hex head bolts (AS 1111.1 / ISO 4014/4017) are the primary form for M14 — driven with a 22 mm spanner or socket, these are used in bolted structural connections, heavy machinery assembly, and flanged joints. M14 socket cap screws (ISO 4762, 12 mm hex key drive) are used in precision engineering, tooling, and machine building applications where a higher torque-to-size ratio and recessed drive are beneficial. M14 structural bolts conforming to AS/NZS 1252 are used in high-strength structural steel connections. M14 is also found in eye bolts for medium-duty rigging and lifting applications, and in flange bolts for pipe connections.

Grades and Materials

Grade 8.8 M14 hex bolts (800 MPa tensile, 640 MPa yield) are the standard specification for mechanical and structural applications, typically zinc-plated. Grade 10.9 M14 bolts are available for high-clamp machinery and clamping applications. M14 stainless steel bolts in A2-70 or A4-80 are used in corrosive, outdoor, marine, and food-grade environments. Galvanised M14 bolts are used in outdoor structural applications including farm infrastructure, civil works, and bridges.

Dimensions and Thread Data

M14 standard coarse pitch is 2.0 mm; fine pitch M14×1.5 is available for specific applications. Hex head across-flats: 22 mm. Socket cap screw hex drive: 12 mm. Typical stock lengths: 25 mm to 300 mm. Thread engagement minimum: 14 mm in steel, 21 mm in aluminium. Tightening torque for Grade 8.8 M14 (dry): approximately 136 N·m — always verify with the specific fastener manufacturer's data.

Applications

M14 bolts are commonly specified in heavy agricultural equipment (headers, balers, and tractors), earthmoving and civil construction machinery (graders, dozers, excavators), industrial gearboxes and drives, heavy transport (truck chassis and trailer frames), large-scale conveyor structures, mining equipment, and flanged pipeline connections. In structural steel fabrication, M14 is used in secondary connections where M12 is undersized and M16 is unnecessarily large. The size also appears in heavy automotive applications including suspension and axle mounting.

Selecting the Right M14 Bolt

Choose Grade 8.8 for standard engineered connections in steel; upgrade to Grade 10.9 where higher clamp loads are specified by the OEM or design engineer. For outdoor or corrosive service, specify stainless or hot-dip galvanised. Always pair with the correct M14 nut (ISO 4032 or heavy hex nut for structural connections) and appropriate washer. In structural steel applications, refer to AS 4100 for bolt tightening method (snug-tight or fully-tensioned) and minimum bolt spacing. The AIMS team can assist with grade selection and bulk pricing for large fastener orders.

AIMS Industrial supplies M14 bolts in Grade 8.8 zinc-plated, Grade 10.9, and stainless steel in a range of lengths from Sydney stock. Contact us for trade pricing, bulk orders, and Australia-wide delivery.