SCM440 / 4140
SCM440 is specifically used in high-strength fasteners and has such advantages as stable components, low hazardous elements, high purity of steel content, small practical decarburized depth and few surface flaws; as well as easy spheroidizing annealing, low breakage rate in cold upsetting performance, stable quality in heat treatment and even hardness for a wide range of applications in engines, die molds, gears and driving parts.
Specification
| TAIWAN - CNS |
CHINA - GB |
JAPAN - JIS |
USA - ASTM |
GERMANY - DIN |
| SCM440 |
42CrMoA |
SCM440 |
4140, 4142 |
42CrMo4, 42CrMoS4 |
Product Specification
| Shape |
Size |
| Round Bar |
13 14 15 16 17 18 19 20 21 22 24 25 26 28 30 32 34 36 38 40 42 44 45 46 48 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 315 325 335 345 355 365 375 385 395 405 415 425 435 445 455 465 475 485 495 505 515 525 535 545 555 565 575 585 595 605 |
Product Feature
- Excellent harden ability for deep harden in greater than the ordinary case hardening for anti-sawing locks.
- Less tendency for temper brittleness.
- Good performance in high temperature processing with a nice appearance afterwards.
- Good performance in weld ability.
- Good performance in impact absorption, such as where the hammer may bounce back and has barely any damage caused upon impact.
Advantages:
- Good performance in processing.
- Good performance in impact absorption.
- Easy welding.
Heat treatment conditions
| Annealing |
Normalize |
Quench |
Tempering |
| 830 Furnace cooling |
830~ 880 Air cooling |
830~ 880 Oil cooling |
530~ 630 Prompt cooling |
Mechanical properties
| Tensile strength kgf/mm² |
Yield strength kgf/mm² |
Elongation % |
Cross section reduction rate % |
Impact value |
Hardness Hb |
| ≧100 |
≧85 |
≧12 |
≧45 |
≧6 |
285~352 |