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Hóa học
Thông số hóa học của tiêu chuẩn DIN 931 cũng chính là thông số hóa học của tiêu chuẩn ISO 898-1.
| Property Class | Material and heat treatment | Chemical Composition Limit | Tempering | |||
| (cast analysis, %) | Temp, ºC, min | |||||
| C | P, max | S, max | B, max | |||
| 4.6 | Carbon steel or carbon steel with additives | 0.55 max | 0.05 | 0.06 | Not specified | – |
| 4.8 | ||||||
| 5.6 | 0.13 – 0.55 | |||||
| 5.8 | 0.55 max | |||||
| 6.8 | 0.15 – 0.55 | |||||
| 8.8 | Carbon steel with additives (e.g. Boron or Mn or Cr) quenched and tempered | 0.15 – 0.40 | 0.025 | 0.025 | 0.003 | 425 |
| Carbon steel quenched and tempered | 0.25 – 0.55 | |||||
| Alloy steel quenched and tempered | 0.20 – 0.55 | |||||
| 9.8 | Carbon steel with additives (e.g. Boron or Mn or Cr) quenched and tempered | 0.15 – 0.40 | 0.025 | 0.025 | 0.003 | 425 |
| Carbon steel quenched and tempered | 0.25 – 0.55 | |||||
| Alloy steel quenched and tempered | 0.20 – 0.55 | |||||
| 10.9 | Carbon steel with additives (e.g. Boron or Mn or Cr) quenched and tempered | 0.20 – 0.55 | 0.025 | 0.025 | 0.003 | 425 |
| Carbon steel quenched and tempered | 0.25 – 0.55 | |||||
| Alloy steel quenched and tempered | 0.20 – 0.55 | |||||
| 12.9 | Alloy steel quenched and tempered | 0.30 – 0.50 | 0.025 | 0.025 | 0.003 | 425 |
| 12.9 | Carbon steel with additives (e.g. Boron or Mn or Cr or Molybdenum) quenched and tempered | 0.28 – 0.50 | 0.025 | 0.025 | 0.003 | 380 |
Cơ tính
Cũng như thông số hóa học, thông số cơ tính của tiêu chuẩn DIN 931 cũng chính là thông số cơ tính của tiêu chuẩn ISO 898-1.
Bảng 1: Mechanical Property
| Mechanical Property | Property Class | ||||||||||
| 4.6 | 4.8 | 5.6 | 5.8 | 6.8 | 8.8 | 9.8 | 10.9 | 12.9/ | |||
| M16 and | Over M16 | M16 and under | 12.9 | ||||||||
| under | |||||||||||
| Tensile strength, Rm, MPa | nom. | 400 | 500 | 600 | 800 | 900 | 1000 | 1200 | |||
| min. | 400 | 420 | 500 | 520 | 600 | 800 | 830 | 900 | 1040 | 1220 | |
| Lower yield strength, ReL, MPa | nom. | 240 | — | 300 | — | — | — | — | — | — | — |
| min. | 240 | — | 300 | — | — | — | — | — | — | — | |
| Stress at 0,2 % non-proportional | nom. | — | — | — | — | — | 640 | 640 | 720 | 900 | 1080 |
| elongation, Rp0,2, MPa | min. | — | — | — | — | — | 640 | 660 | 720 | 940 | 1100 |
| Stress at 0,0048 d non-proportional | nom. | — | 320 | — | 400 | 480 | — | ||||
| elongation for full-size fasteners, Rpf, MPa | min. | — | 340 | — | 420 | 480 | — | ||||
| Stress under proof load, Sp, MPa | nom. | 225 | 310 | 280 | 380 | 440 | 440 | 600 | 650 | 830 | 970 |
| Proof strength ratio | Sp,nom/ReL min | 0,94 | 0,91 | 0,93 | 0,9 | 0,92 | 0,91 | 0,91 | 0,9 | 0,88 | 0,88 |
| Sp,nom/Rp0,2 min | |||||||||||
| Sp,nom/Rpf min | |||||||||||
| Percentage elongation after fracture for | min. | 22 | — | 20 | — | — | 12 | 12 | 10 | 9 | 8 |
| machined test pieces, A, % | |||||||||||
| Percentage reduction of area after fracture for | min. | — | 52 | 48 | 48 | 44 | |||||
| machined test pieces, Z, % | |||||||||||
| Elongation after fracture for full-size | min. | — | 0,24 | — | 0,22 | 0,2 | — | ||||
| fasteners, Af | |||||||||||
| Head soundness | No fracture | ||||||||||
| Vickers hardness, | min. | 120 | 130 | 155 | 160 | 190 | 250 | 255 | 290 | 320 | 385 |
| HV F ≥ 98 N | max. | 220 | 250 | 320 | 335 | 360 | 380 | 435 | |||
| Brinell hardness, HBW | min. | 114 | 124 | 147 | 152 | 181 | 238 | 242 | 276 | 304 | 304 |
| F = 30 D2 | max. | 209 | 238 | 304 | 318 | 342 | 361 | 414 | |||
| Rockwell hardness, HRB | min. | 67 | 71 | 79 | 82 | 89 | — | ||||
| max. | 95 | 89 | — | ||||||||
| Rockwell hardness, HRC | min. | — | 22 | 23 | 23 | 32 | 39 | ||||
| max. | — | 32 | 34 | 37 | 39 | 44 | |||||
| Surface hardness, HV 0,3 | max. | — | -1 | (1),(2) | (1).(3) | ||||||
| Height of non-decarburized thread zone, | min. | — | 1/2 H1 | 2/3 H1 | 3/4 H1 | ||||||
| E, mm | |||||||||||
| Depth of complete decarburization | max. | — | 0,015 | ||||||||
| in the thread, G, mm | |||||||||||
| Reduction of hardness after retempering, HV | max. | — | 20 | ||||||||
| Breaking torque, MB, N⋅m | min. | — | in accordance with ISO 898-7 | ||||||||
| Impact strength, KV, J | min. | — | 27 | — | 27 | -4 | |||||
| Surface integrity in accordance with | ISO 6157-1 | ISO 6157-3 | |||||||||
| (1) Surface hardness shall not be more than 30 Vickers points above the measured core hardness of the fastener when determination of both surface hardness | |||||||||||
| and core hardness are carried out with HV 0,3. | |||||||||||
| (2) Any increase in hardness at the surface which indicates that the surface hardness exceeds 390 HV is not acceptable. | |||||||||||
| (3) Any increase in hardness at the surface which indicates that the surface hardness exceeds 435 HV is not acceptable. | |||||||||||
| (4) Value for KV is under investigation. | |||||||||||
Bảng 2: Proof load
| Thread | Nominal stress area | Property class | ||||||||
| d | As, nom, mm2 | 4.6 | 4.8 | 5.6 | 5.8 | 6.8 | 8.8 | 9.8 | 9.8 | 12.9/12.9 |
| Proof load, Fp (As,nom × Sp,nom), N | ||||||||||
| M12 | 84,3 | 19 000 | 26 100 | 23 600 | 32 000 | 37 100 | 48 900 | 54 800 | 70 000 | 81 800 |
| M16 | 157 | 35 300 | 48 700 | 44 000 | 59 700 | 69 100 | 91 000 | 102 000 | 130 000 | 152 000 |
| M20 | 245 | 55 100 | 76 000 | 68 600 | 93 100 | 108 000 | 147 000 | — | 203 000 | 238 000 |
| M22 | 303 | 68 200 | 93 900 | 84 800 | 115 000 | 133 000 | 182 000 | — | 252 000 | 294 000 |
| M24 | 353 | 79 400 | 109 000 | 98 800 | 134 000 | 155 000 | 212 000 | — | 293 000 | 342 000 |
| M27 | 459 | 103 000 | 142 000 | 128 000 | 174 000 | 202 000 | 275 000 | — | 381 000 | 445 000 |
| M30 | 561 | 126 000 | 174 000 | 157 000 | 213 000 | 247 000 | 337 000 | — | 466 000 | 544 000 |
| M33 | 694 | 156 000 | 215 000 | 194 000 | 264 000 | 305 000 | 416 000 | — | 576 000 | 673 000 |
| M36 | 817 | 184 000 | 253 000 | 229 000 | 310 000 | 359 000 | 490 000 | — | 678 000 | 792 000 |
| M39 | 976 | 220 000 | 303 000 | 273 000 | 371 000 | 429 000 | 586 000 | — | 810 000 | 947 000 |
Bảng 3: Tensile load
| Thread | Nominal stress area | Property class | ||||||||
| d | As, nom, mm2 | 4.6 | 4.8 | 5.6 | 5.8 | 6.8 | 8.8 | 9.8 | 9.8 | 12.9/12.9 |
| Minimum ultimate tensile load, Fm min (As, nom × Rm, min), N | ||||||||||
| M12 | 84,3 | 33 700 | 35 400 | 42 200 | 43 800 | 50 600 | 67 400 | 75 900 | 87 700 | 103 000 |
| M16 | 157 | 62 800 | 65 900 | 78 500 | 81 600 | 94 000 | 125 000 | 141 000 | 163 000 | 192 000 |
| M20 | 245 | 98 000 | 103 000 | 122 000 | 127 000 | 147 000 | 203 000 | — | 255 000 | 299 000 |
| M22 | 303 | 121 000 | 127 000 | 152 000 | 158 000 | 182 000 | 252 000 | — | 315 000 | 370 000 |
| M24 | 353 | 141 000 | 148 000 | 176 000 | 184 000 | 212 000 | 293 000 | — | 367 000 | 431 000 |
| M27 | 459 | 184 000 | 193 000 | 230 000 | 239 000 | 275 000 | 381 000 | — | 477 000 | 560 000 |
| M30 | 561 | 224 000 | 236 000 | 280 000 | 292 000 | 337 000 | 466 000 | — | 583 000 | 684 000 |
| M33 | 694 | 278 000 | 292 000 | 347 000 | 361 000 | 416 000 | 576 000 | — | 722 000 | 847 000 |
| M36 | 817 | 327 000 | 343 000 | 408 000 | 425 000 | 490 000 | 678 000 | — | 850 000 | 997 000 |
| M39 | 976 | 390 000 | 410 000 | 488 000 | 508 000 | 586 000 | 810 000 | — | 1 020 000 | 1 200 000 |
