M30 Nut Dimensions: Hex & Thin Series

Q: What size wrench or spanner do I need for an M30 nut?

An M30 hex nut typically requires a 46 mm wrench or socket. The standard width across flats (s) for an M30 nut is 46.00 mm. Due to the extreme torque required for M30 fasteners, hydraulic torque wrenches or heavy-duty impact tools are mandatory for proper industrial installation.

Q: 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 vibration or rotation.

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

No. Because the Thin Series has fewer threads in contact with the bolt, it has a lower proof load. For M30 fasteners, which are frequently used in safety-critical structural joints, using a thin nut as the primary fastener is highly dangerous as the threads are likely to strip or shear under high tension. Always use a Regular Series nut for primary load-bearing applications.

M30 nut dimensions or sizes are critical for bridge construction, heavy industrial foundations, and large-scale power plant equipment. This size is specifically engineered to mate with fasteners having a 30.00 mm nominal diameter and is available in M30 x 3.5 for the coarse series and M30 x 2.0 for the fine series.

This charts cover 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), DIN 13-21 (fine series), and ISO 68-1 standards to ensure a precise fit and reliable engagement across heavy-capacity 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

M30 x 3.5 Hex Nut – DIN 13-1/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	30	30.785
Pitch Diameter	27.727	28.007
Minor Diameter	26.211	26.771
Thread Pitch	3.5

M30 x 2.0 Hex Nut – DIN 13-21/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	30	30.513
Pitch Diameter	28.701	28.925
Minor Diameter	27.835	28.21
Thread Pitch	2.0

M30 x 1.5 Hex Nut – DIN 13-21/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	30	30.416
Pitch Diameter	29.026	29.226
Minor Diameter	28.376	28.676
Thread Pitch	1.5

M30 x 1.0 Hex Nut – DIN 13-21/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	30	30.314
Pitch Diameter	29.35	29.52
Minor Diameter	28.917	29.153
Thread Pitch	1.0

M30 Hex Nut – DIN 934/ISO 4032 & ISO 8673
Diameter	30	32.4
Width Across Flats	45	46
Width Across Corners	50.85	Not specified
Height / Thickness	24.3	25.6

M30 Thin / Half Nut – DIN 439/ISO 4035 & ISO 8675
Diameter	30	32.4
Width Across Flats	45	46
Width Across Corners	50.85	Not specified
Height / Thickness	13.9	15

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Frequently Asked Questions

What size wrench or spanner do I need for an M30 nut?

An M30 hex nut typically requires a 46 mm wrench or socket. The standard width across flats (s) for an M30 nut is 46.00 mm. Due to the extreme torque required for M30 fasteners, hydraulic torque wrenches or heavy-duty impact tools are mandatory for proper industrial installation.

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 vibration or rotation.

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

No. Because the Thin Series has fewer threads in contact with the bolt, it has a lower proof load. For M30 fasteners, which are frequently used in safety-critical structural joints, using a thin nut as the primary fastener is highly dangerous as the threads are likely to strip or shear under high tension. Always use a Regular Series nut for primary load-bearing applications.