4340 DIN 1.6580 30CrNiMo8 SNCM431 Hardened Steel Round Bar
- Model
- 4340， DIN1.6580， 30CrNiMo8，SNCM431
Item specifics
- Diameter
- 50-260mm
- Delivery condition
- harden
- Surface condition
- black, bright
Review
Description
Applications
Alloyed heat treatable steel with a typical tensile strength of 1100 -1300 N/mm². Used for highly stressed components, where the combination of high strength with tenaciousness is of utmost importance. High cold formability: Parts of different shape can be manufactured, a favorablefibering for stress, a very good surface condition and an high dimensional accuracy. When cold formed the smooth surface leads to an increased fatigue and vibratory strength.
Chemical Composition(%)
Steel Grade | C | Mn | Si | P | S | Cr | Ni | Mo |
30CrNiMo8 | 0.26-0.34 | 0.50-0.80 | 0.40 max | 0.025 max | 0.035 max | 1.80-2.20 | 1.80-2.20 | 0.30-0.50 |
4340 | 0.38–0.43 | 0.60-0.80 | 0.15-0.35 | 0.035 max | 0.040 max | 0.70-0.90 | 1.65-2.00 | 0.20-0.30 |
SNCM431 | 0.27-0.35 | 0.60-0.90 | 0.15-0.35 | 0.030 max | 0.030 max | 0.60-1.10 | 1.60-2.00 | 0.15-0.30 |
All Grades Comparison
Material no. | DIN | BS | ASTM |
1.658 | 30CrNiMo8 | 823M30 | 4340 |
AFNOR | ISO | ГOCT | JIS |
30CND8 | 31CrNiMo8 | 3KH3M3F | SNCM431 |
Mechanical Properties(T=20°C if not differently stated)
Heat treatment state | Diameter(mm) | Rm (Mpa) | Rp0.2 (Mpa) | Fracture elongation A5 (%) | Notch impact energy ISO-V [J] | Hardness (HB) |
SOFT ANNEALED | / | 844 min | / | / | / | 250 max |
ISOTHERMAL ANNEALED | / | 615-815 | / | / | / | 183-242 |
QUENCHED AND TEMPERED | 16 max | 880-1080 | 685 min | 16 min | 40 min | 289-347 |
QUENCHED AND TEMPERED | 16-40 | 930-1080 | 735 min | 16 min | 40 min | 275-318 |
QUENCHED AND TEMPERED | 40-100 | 880-1030 | 685 min | 17 min | 40 min | 261-303 |
QUENCHED AND TEMPERED | 100-250 | 785-935 | 635 min | 18 min | 35 min | 233-276 |
QUENCHED AND TEMPERED | 250-500 | 735-885 | 590 min | 16 min | 35 min | 218-262 |
