Proof Load Values for Hex Nuts (N)
| Thread, d | Pitch, P | Proof Load as per ISO898‑2 | Proof Load as per DIN267‑4 | Proof Load as per BS4190 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Class 8 | Class 10 | Class 12 | Class 8 | Class 10 | Class 12 | Class 8 | Class 10 | Class 12 | ||
| M5 | 0.8 | 12,140 | 14,800 | 16,300 | 11,400 | 14,200 | 17,000 | 11,400 | 14,800 | 17,000 |
| M6 | 1.0 | 17,200 | 20,900 | 23,100 | 16,000 | 20,000 | 24,000 | 16,000 | 20,000 | 24,000 |
| M8 | 1.25 | 31,800 | 38,100 | 42,500 | 29,000 | 36,500 | 43,000 | 29,000 | 36,500 | 43,000 |
| M10 | 1.5 | 50,500 | 60,300 | 67,300 | 46,000 | 58,000 | 69,500 | 46,000 | 58,000 | 69,500 |
| M12 | 1.75 | 74,200 | 88,500 | 100,300 | 67,000 | 84,000 | 100,000 | 67,000 | 84,000 | 100,000 |
| M14 | 2.0 | 101,200 | 120,800 | 136,900 | 92,000 | 115,000 | 138,000 | -- | -- | -- |
| M16 | 2.0 | 138,200 | 164,900 | 186,800 | 126,000 | 157,000 | 188,000 | 125,000 | 157,000 | 188,000 |
| M18 | 2.5 | 176,600 | 203,500 | 230,400 | 154,000 | 192,000 | 230,000 | -- | -- | -- |
| M20 | 2.5 | 225,400 | 259,700 | 294,000 | 196,000 | 245,000 | 294,000 | 196,000 | 245,000 | 294,000 |
| M22 | 2.5 | 278,800 | 321,200 | 363,600 | 242,000 | 303,000 | 364,000 | 242,000 | 303,000 | 364,000 |
| M24 | 3.0 | 324,800 | 374,200 | 423,600 | 282,000 | 353,000 | 423,000 | 282,000 | 353,000 | 423,000 |
| M27 | 3.0 | 422,300 | 486,500 | 550,800 | 367,000 | 459,000 | 550,000 | 367,000 | 459,000 | 550,000 |
| M30 | 3.5 | 516,100 | 594,700 | 673,200 | 448,000 | 561,000 | 673,000 | 448,000 | 561,000 | 673,000 |
| M33 | 3.5 | 638,500 | 735,600 | 832,800 | 555,000 | 694,000 | 833,000 | 555,000 | 694,000 | 833,000 |
| M36 | 4.0 | 751,600 | 866,000 | 980,400 | 653,000 | 817,000 | 980,000 | 653,000 | 817,000 | 980,000 |
| M39 | 4.0 | 897,900 | 1,035,000 | 1,171,000 | 780,000 | 976,000 | 1,170,000 | 780,000 | 976,000 | 1,170,000 |
| M42 | 4.5 | -- | -- | -- | -- | -- | -- | 896,000 | 1,120,000 | 1,340,000 |
| M45 | 4.5 | -- | -- | -- | -- | -- | -- | 1,400,000 | 1,300,000 | 1,560,000 |
| M48 | 5.0 | -- | -- | -- | -- | -- | -- | 1,180,000 | 1,470,000 | 1,760,000 |
| M52 | 5.0 | -- | -- | -- | -- | -- | -- | 1,410,000 | 1,760,000 | 2,110,000 |
| M56 | 5.5 | -- | -- | -- | -- | -- | -- | 1,620,000 | 2,030,000 | 2,440,000 |
| M60 | 5.5 | -- | -- | -- | -- | -- | -- | 1,890,000 | 2,360,000 | 2,830,000 |
| M64 | 6.0 | -- | -- | -- | -- | -- | -- | 2,140,000 | 2,680,000 | 3,220,000 |
| M68 | 6.0 | -- | -- | -- | -- | -- | -- | 2,450,000 | 3,060,000 | 3,670,000 |
Hardness Properties for Hex Nuts - Style 1 (Vickers Hardness, HV)
| Thread, d | Hardness as per ISO898‑2 | Hardness as per DIN267‑4 | Hardness as per BS4190 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Class 8 | Class 10 | Class 12 | Class 8 | Class 10 | Class 12 | Class 8 | Class 10 | Class 12 | ||
| M5 ‑ M16 | min. | 200 | 272 | 272 | - | - | - | - | - | - |
| max. | 302 | 353 | 353 | 302 | 353 | 353 | 310 | 370 | 395 | |
| M18 ‑ M39 | min. | 233 | 272 | 272 | - | - | - | - | - | - |
| max. | 353 | 353 | 353 | 302 | 353 | 353 | 310 | 370 | 395 | |
DIN267-Part 10 specifies the technical delivery conditions for hot-dip galvanized bolts and nuts, diameter size M6 to M36,coarse thread.
Minimum Failure Loads for Hot-Dip Galvanized Bolts and Proof Loads for Hot-dip Galvanized Nuts with oversize thread.
| Thread size |
Pitch, (P) | Stress area, (mm2) |
Property class bolt/nut | |
|---|---|---|---|---|
| 8.8/8 | 10.9/10 | |||
| Minimum failure load of bolt or proof load for nut, (N) |
||||
| M6 | 1.0 | 16.4 | 13,100 | 17,100 |
| M8 | 1.25 | 31.3 | 25,000 | 32,600 |
| M10 | 1.5 | 50.9 | 40,700 | 52,900 |
| M12 | 1.75 | 75.1 | 60,100 | 78,100 |
| M14 | 2.0 | 104 | 83,200 | 108,000 |
| M16 | 2.0 | 144 | 115,000 | 150,000 |
| M18 | 2.5 | 177 | 147,000 | 184,000 |
| M20 | 2.5 | 227 | 188,000 | 236,000 |
| M22 | 2.5 | 284 | 236,000 | 295,000 |
| M24 | 3.0 | 329 | 273,000 | 342,000 |
| M27 | 3.0 | 433 | 359,000 | 450,000 |
| M30 | 3.5 | 530 | 440,000 | 551,000 |
| M33 | 3.5 | 659 | 547,000 | 685,000 |
| M36 | 4.0 | 777 | 645,000 | 808,000 |
Proof Load for Hot-dip Galvanized Nuts
| Thread size |
Pitch, (P) | Stress area, (mm2) |
Class 8 | Class 10 |
|---|---|---|---|---|
| Proof load, (N) | ||||
| M6 | 1.0 | 16.4 | 9,510 | 13,610 |
| M8 | 1.25 | 31.3 | 18,150 | 25,980 |
| M10 | 1.5 | 50.9 | 29,500 | 42,200 |
| M12 | 1.75 | 75.1 | 43,600 | 62,300 |
| M14 | 2.0 | 104 | 60,300 | 86,300 |
| M16 | 2.0 | 144 | 83,500 | 119,000 |
| M18 | 2.5 | 177 | 106,000 | 147,000 |
| M20 | 2.5 | 227 | 136,000 | 188,000 |
| M22 | 2.5 | 284 | 170,000 | 236,000 |
| M24 | 3.0 | 329 | 197,000 | 273,000 |
| M27 | 3.0 | 433 | 260,000 | 359,000 |
| M30 | 3.5 | 530 | 318,000 | 440,000 |
| M33 | 3.5 | 659 | 395,000 | 547,000 |
| M36 | 4.0 | 777 | 466,000 | 645,000 |
For detailed information, please refer to complete governing standards.
SAE J995 specifies the requirements for high tensile and alloy steel inch-series nuts. Sizes covered range from ¼" to 1-½" diameter.
Proof Load for ANSI B18.2.2 Hex Nut
| Size | Proof Load (lbf) for UNC Hex Nut | Size | Proof Load (lbf) for UNF Hex | ||
|---|---|---|---|---|---|
| Grade 5 | Grade 8 | Grade 5 | Grade 8 | ||
| 1/4"-20 | 3,800 | 4,750 | 1/4"-28 | 4,000 | 5,460 |
| 5/16"-18 | 6,300 | 7,850 | 5/16"-24 | 6,300 | 8,700 |
| 3/8"-16 | 9,300 | 11,600 | 3/8"-24 | 9,550 | 13,150 |
| 7/16"-14 | 12,800 | 15,900 | 7/16"-20 | 13,000 | 17,800 |
| 1/2"-13 | 17,000 | 21,300 | 1/2"-20 | 17,450 | 24,000 |
| 9/16"-12 | 21,800 | 27,300 | 9/16"-18 | 22,150 | 30,450 |
| 5/8"-11 | 27,100 | 33,900 | 5/8"-18 | 27,900 | 38,400 |
| 3/4"-10 | 40,100 | 50,100 | 3/4"-16 | 40,650 | 55,950 |
| 7/8"-9 | 55,400 | 69,300 | 7/8"-14 | 55,500 | 76,350 |
| 1"-8 | 72,700 | 90,900 | 1"-12 | 72,300 | 99,450 |
| 1-1/8"-7 | 80,100 | 114,000 | 1-1/8"-12 | 80,450 | 128,400 |
| 1-1/4"-7 | 102,000 | 145,000 | 1-1/4"-12 | 100,850 | 160,950 |
| 1-3/8"-6 | 121,000 | 173,000 | 1-3/8"-12 | 123,800 | 197,250 |
| 1-1/2"-6 | 148,000 | 211,000 | 1-1/2"-12 | 148,600 | 237,150 |
Hardness Requirements for ANSI B18.2.2 Hex Nuts
| Nut Grade | Size | Hardness |
|---|---|---|
| 5 | 1/4" to 1-1/2" | 32 HRC Max |
| 8 | 1/4" to 5/8" | 24--32 HRC |
| 8 | Over 5/8" to 1" | 26--34 HRC |
| 8 | Over 1" to 1-1/2" | 26--36 HRC |
For detailed information, please refer to complete governing standards.