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Date Published:Jan. 16. 2025

What are Hex Nuts?

➡Description of Special Screws for Engineers

What are Hex Nuts?

Hex nuts are parts with threaded through holes in the middle of a hex shape; they are used along with bolts for tightening and fixing materials.

Usage and applications

They are widely used in equipment, machinery, and vehicles. Smaller sizes are used in precision equipment, while larger ones are used in construction and shipbuilding sites.
Nuts with excellent heat resistance and corrosion resistance are also used in semiconductor manufacturing equipment.
➡The Semiconductor Industry and NBK's Initiatives

Hexagon nut shape and dimension

Degree of finishing: Medium (Degree of finishing for below M6: High)

Unit : mm
Nominal diameter of thread(d)
m1  φdw・φdk' 
Coarse  Fine  Basic Dimension Allowance Basic Dimension Allowance Basic Dimension Allowance About About
M2   -   1.6  0
-0.25
  1.2  0
-0.25
  4  0
-0.2
  4.6   3.8
M2.5   -   2   1.6   5   5.8   4.7
M3  -   2.4   1.8   5.5   6.4   5.3
(M3.5)  -   2.8   2   6   6.9   5.8
M4  -   3.2  0
-0.30
  2.4   7   8.1   6.8
M5  -   4   3.2  0
-0.3
  8   9.2   7.8
M6  -   5  0
-0.48
  3.6  0
-0.48
10  0
-0.6
11.5   9.8
(M7)  -   5.5   4.2 11  0
-0.7
12.7 10.8
M8 M8×1    6.5  0
-0.58
  5 13 15 12.5
M10 M10×1.25   8   6 17 19.6 16.5
M12 M12×1.25 10   7  0
-0.58
19   0
-0.8
21.9 18
(M14) (M14×1.5) 11  0
-0.70
  8 22 25.4 21
M16 M16×1.5  13 10 24 27.7 23
(M18) (M18×1.5) 15 11  0
-0.70
27 31.2 26
M20 M20×1.5  16 12 30 34.6 29
(M22) (M22×1.5) 18 13 32   0
-1.0
37 31
M24 M24×2 19   0
-0.84
14 36 41.6 34
(M27) (M27×2) 22 16 41 47.3 39
M30 M30×2 24 18 46 53.1 44
(M33) (M33×2)  26 20  0
-0.84
50 57.7 48
M36 M36×3  29 21 55  0
-1.2
63.5 53
(M39) (M39×3)  31  0
-1.0
23 60 69.3 57
M42   34 25 65 75 62
M45   36 27 70 80.8 67
M48   38 29 75 86.5 72
(M52)   42 31  0
-1.0
80 92.4 77
M56   45 34 85  0
-1.4
98.1 82
(M60)   48 36 90 104 87
M64   51  0
-1.2
38 95 110 92

Remark: Avoid using those with any nominal diameter of screw in parentheses as long as possible.

Recommended Hex Nut Products (special materials, miniature screws/precision screws, theft prevention)

Material:PTFE (Polytetrafluoroethylene)

・Plastic with excellent heat resistance, electrical properties, chemical resistance, and abrasion resistance; almost no chemicals can penetrate PTFE.
・It also has high flame retardance which clears the UL 94 V-0 standard.

SPT-N(Made of PTFE)

Material:PEEK

・Thermoplastic super engineering plastic superior in physical and chemical properties.
・Excellent chemical resistance. It remains almost unaffected by chemicals other than concentrated sulfuric acid, concentrated nitric acid, and concentrated hydrofluoric acid.
・With excellent heat resistance and water resistance, it retains strength at high temperatures.
・It features outstanding resistance to wear, shock, and fatigue.
・It also has high flame retardance which clears the UL 94 V-0 standard.
・・Properties and precautions for the use of plastic screws ➡Properties of plastic screws

SPE-N(Made of PEEK)

Material:Molybdenum

・Pure Molybdenum
・Melting point: 2,623℃. Excellent heat resistance.
・Cleanroom Washing/Cleanroom Packing➡Cleanroom Wash / Cleanroom Packing Service

SHNM(Made of Molybdenum)

For miniature screws and precision screws.

NBK defines "Miniature Screws" and "Precision Screws" as small screws with a thread nominal diameter of M2.6 or less. The lineup includes various materials and shapes.
Stainless steel and plastic nuts are also available for use with miniature screws and precision screws.

For miniature screws and precision screws.

For Theft Prevention

Theft prevention nuts mountable with commercially available tools.
Made of SUS304 and resistant to rust, they are well suited to theft prevention for outdoor structures like truck batteries or outdoor air conditioners.

Prevention of truck battery theft
Prevention of outside AC unit theft
SHNRS(For Theft Prevention)

Support for Customized Products

Sixty percent of NBK's screw orders consist of customized products not listed in the catalog.
We provide a wide range of customization options tailored to customer requirements.
Feel free to contact our customer service team regarding inquiries about nuts.

Contact us here

Find information on hex nut recommended products here

Product Introduction Safety measures/precautionary measures Machine Tools Semiconductor Manufacturing Equipment Food Machinery Automotive Manufacturing Process Medical Equipment FA Devices Description of Special Screws for Engineers Special Screws