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)
Nominal diameter of thread(d) |
m | m1 | s | e | 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.
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
Material:Molybdenum
・Pure Molybdenum
・Melting point: 2,623℃. Excellent heat resistance.
・Cleanroom Washing/Cleanroom Packing➡Cleanroom Wash / Cleanroom Packing Service
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 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.
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