M64 Nut Dimensions: Hex & Thin Series

M64 nut dimensions or sizes are critical for offshore oil platforms, heavy bridge abutments, and large-scale industrial press foundations. This size is specifically engineered to mate with fasteners having a 64.00 mm nominal diameter and is commonly available in M64 x 6.0 for the coarse series.

This charts covers both the Regular Series (DIN 934 / ISO 4032) for standard load-bearing applications and the Thin or Half Series (DIN 439 / ISO 4035), which is ideal for jam nut or lock nut configurations or applications with limited vertical clearance. The thread dimensions comply with DIN 13-1 (coarse) and ISO 68-1 standards to ensure a precise fit and reliable engagement across extreme-load metric fastening systems.

Disclaimer: Actual dimensions, including the width across flats (spanner or wrench size), nut height, and thread tolerance may vary depending on the specific manufacturing class and material — always verify with the official product datasheet before use or buying.

Nut internal thread diagram depicting major diameter, minor diameter, and pitch diameter
Nut body diagram depicting width across flats, width across corners, diameter, and thickness or height
M64 x 6.0 Hex Nut – DIN 13-1/ISO 68-1
DimensionSize (mm)
MinMax
Major Diameter 64 65.241
Pitch Diameter 60.103 60.478
Minor Diameter 57.505 58.305
Thread Pitch 6.0
M64 x 4.0 Hex Nut – DIN 13-21/ISO 68-1
DimensionSize (mm)
MinMax
Major Diameter 64 64.892
Pitch Diameter 61.402 61.717
Minor Diameter 59.67 60.27
Thread Pitch 4.0
M64 x 3.0 Hex Nut – DIN 13-21/ISO 68-1
DimensionSize (mm)
MinMax
Major Diameter 64 64.713
Pitch Diameter 62.051 62.331
Minor Diameter 60.752 61.252
Thread Pitch 3.0
M64 x 2.0 Hex Nut – DIN 13-21/ISO 68-1
DimensionSize (mm)
MinMax
Major Diameter 64 64.525
Pitch Diameter 62.701 62.937
Minor Diameter 61.835 62.21
Thread Pitch 2.0
M64 x 1.5 Hex Nut – DIN 13-21/ISO 68-1
DimensionSize (mm)
MinMax
Major Diameter 64 64.429
Pitch Diameter 63.026 63.238
Minor Diameter 62.376 62.676
Thread Pitch 1.5
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Frequently Asked Questions

What size wrench or spanner do I need for an M64 nut?

An M64 hex nut typically requires a 95 mm wrench or socket. The standard width across flats (s) for an M64 nut is 95.00 mm. At this scale, manual wrenching is no longer feasible; installation requires the use of hydraulic bolt tensioners or high-capacity hydraulic torque wrenches to reach the necessary clamping force.

What is a jam nut?

A jam nut is a low-profile hex nut, typically from the Thin Series (DIN 439), that is used to lock a standard nut in place. By tightening a standard nut against a jam nut, you create internal tension between the threads of both nuts and the bolt. This “jams” the assembly together, providing a mechanical lock that prevents loosening caused by extreme vibration or seismic-level structural movements.

Can a Thin Series nut handle the same torque as a Regular nut?

No. Because the Thin Series has significantly fewer threads in contact with the bolt, it has a lower proof load. For M64 applications—which usually involve critical infrastructure—using a thin nut as the primary fastener is unsafe as the threads are likely to strip or fail under massive tension. Always use a Regular Series nut for primary structural connections.