M14 Nut Dimensions: Hex & Thin Series

Q: What size wrench or spanner do I need for an M14 nut?

An M14 hex nut typically requires a 21 mm wrench or socket (standard for ISO 4032) or a 22 mm wrench (traditional DIN 934 standard). Due to the high torque often required for M14 fasteners, using a 6-point socket is recommended to prevent rounding the hex flats.

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. Applying the high clamping torque required for M14 structural joints to a thin nut will likely strip the threads. Always use a standard height (Regular Series) nut as the primary load-bearing fastener.

Q: Why are Fine Pitch M14 nuts (1.5mm) common in automotive applications?

M14 x 1.5 is a standard wheel lug nut size for many vehicles. Fine threads are preferred in these high-vibration environments because they have a shallower thread angle, which provides better resistance to self-loosening and allows for more precise torque application.

M14 nut dimensions or sizes are critical for automotive wheel hubs, industrial mounting brackets, and heavy structural assemblies. This size is specifically engineered to mate with fasteners having a 14.00 mm nominal diameter and is available in M14 x 2.0 for the coarse series and M14 x 1.5 for the fine 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), DIN 13-21 (fine series), and ISO 68-1 standards to ensure a precise fit and reliable engagement across heavy-duty 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

M14 x 2.0 Hex Nut – DIN 13-1/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	14	14.501
Pitch Diameter	12.701	12.913
Minor Diameter	11.835	12.21
Thread Pitch	2.0

M14 x 1.5 Hex Nut – DIN 13-21/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	14	14.406
Pitch Diameter	13.026	13.216
Minor Diameter	12.376	12.676
Thread Pitch	1.5

M14 x 1.0 Hex Nut – DIN 13-21/ISO 68-1
Dimension	Size (mm)
Dimension	Min	Max
Major Diameter	14	14.304
Pitch Diameter	13.35	13.51
Minor Diameter	12.917	13.153
Thread Pitch	1.0

M14 Hex Nut – DIN 934/ISO 4032 & ISO 8673
Diameter	14	15.1
Width Across Flats	20.67	21
Width Across Corners	23.36	Not specified
Height / Thickness	12.1	12.8

M14 Thin / Half Nut – DIN 439/ISO 4035 & ISO 8675
Diameter	14	15.1
Width Across Flats	21.67	22
Width Across Corners	24.49	Not specified
Height / Thickness	6.42	7

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Frequently Asked Questions

What size wrench or spanner do I need for an M14 nut?

An M14 hex nut typically requires a 21 mm wrench or socket (standard for ISO 4032) or a 22 mm wrench (traditional DIN 934 standard). Due to the high torque often required for M14 fasteners, using a 6-point socket is recommended to prevent rounding the hex flats.

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. Applying the high clamping torque required for M14 structural joints to a thin nut will likely strip the threads. Always use a standard height (Regular Series) nut as the primary load-bearing fastener.

Why are Fine Pitch M14 nuts (1.5mm) common in automotive applications?

M14 x 1.5 is a standard wheel lug nut size for many vehicles. Fine threads are preferred in these high-vibration environments because they have a shallower thread angle, which provides better resistance to self-loosening and allows for more precise torque application.