Chemical composition as per ISO 898-1 for typical grades
| CLASS | MATERIAL AND TREATMENT | C MIN |
C MAX |
P MAX |
S MAX |
B MAX |
TEMPERING TEMP. [C] |
|---|---|---|---|---|---|---|---|
| 8.8 | CARBON STEEL WITH ADDITIVES (E.G. B, MN OR CR) QUENCHED AND TEMPERED | 0.15 (D) | 0.40 | 0.025 | 0.025 | 0.003 | 425 |
| CARBON STEEL QUENCHED AND TEMPERED | 0.25 | 0.55 | 0.035 | 0.025 | |||
| 10.9 | CARBON STEEL WITH ADDITIVES (E.G. B, MN OR CR) QUENCHED AND TEMPERED | 0.15 (D) | 0.35 | 0.025 | 0.025 | 0.003 | 340 |
| CARBON STEEL QUENCHED AND TEMPERED | 0.25 | 0.55 | 0.025 | 0.025 | 0.003 | 425 | |
| CARBON STEEL WITH ADDITIVES (E.G. B, MN OR CR) QUENCHED AND TEMPERED | 0.20 (D) | 0.55 | 0.025 | 0.025 | |||
| ALLOY STEEL QUENCHED AND TEMPERED (G) | 0.20 | 0.55 | 0.025 | 0.025 | |||
| 12.9 | ALLOY STEEL QUENCHED AND TEMPERED (G) | 0.28 | 0.50 | 0.025 | 0.025 | 0.003 | 380 |
| (D) IN CASE OF PLAIN CARBON BORON STEEL WITH A CARBON CONTENT BELOW 0.25% (LADLE ANALYSIS), MIN MANGANESE 0.6% FOR 8.8 AND 0.7% FOR 10.9 | |||||||
| (G) ALLOY STEEL SHALL CONTAIN ONE OF THE FOLLOWING ELEMENTS: CHROMIUM 0.30%, NICKEL 0.30%, MOLYBDENUM 0.20%, VANADIUM 0.10% | |||||||
Mechanical and physical properties as per ISO 898-1 for typical grades
| MECHANICAL OR PHYSICAL PROPERTY | CLASS 8.8 (M16 AND BELOW) |
CLASS 8.8 (ABOVE M16) |
CLASS 10.9 | CLASS 12.9 | |
|---|---|---|---|---|---|
| TENSILE STRENGTH [MPA] | NOM. | 800 | 1000 | 1200 | |
| MIN. | 800 | 830 | 1040 | 1220 | |
| STRESS AT 0.2% NON-PROPORTIONAL ELONGATION (YIELD) [MPA] | NOM. | 640 | 900 | 1080 | |
| MIN. | 640 | 660 | 940 | 1100 | |
| STRESS UNDER PROOF LOAD [MPA] | NOM. | 580 | 600 | 830 | 970 |
| ELONGATION AFTER FRACTURE FOR MACHINED TEST PIECE [%] | MIN. | 12 | 12 | 10 | 8 |
| REDUCTION OF AREA AFTER FRACTURE FOR MACHINED TEST PIECE [%] | MIN. | 52 | 48 | 44 | |
| IMPACT STRENGTH, CHARPY V-NOTCH [J] | MIN. | 27 | 27 | 27 | (UNDER INVESTIGATION) |
Bolts, Screws and Studs (Carbon And Alloy Steel)
Hardness requirement as per ISO 898-1 for typical grades
| HARDNESS SCALE | CLASS 8.8 M16 AND BELOW |
CLASS 8.8 ABOVE M16 |
CLASS 10.9 | CLASS 12.9 | |
|---|---|---|---|---|---|
| VICKERS, HV | MIN. | 250 | 255 | 320 | 385 |
| MAX. | 320 | 335 | 380 | 435 | |
| BRINELL, HB | MIN. | 238 | 242 | 304 | 366 |
| MAX. | 304 | 318 | 361 | 414 | |
| ROCKWELL, HRC | MIN. | 22 | 23 | 32 | 39 |
| MAX. | 32 | 34 | 39 | 44 | |
ISO 898-1: Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs with specified property classes — Coarse thread and fine pitch thread
Please refer also to: Suitability test requirements (BS EN 15048) – CE Marking