37CrS4
1.7038Free-machining variant of 37Cr4 with controlled sulfur addition (0.020–0.040%) for improved chip-breaking during automated machining. Chromium steel with good hardenability for medium cross-sections. Same mechanical properties as 37Cr4 after quenching and tempering. Used for automotive and mechanical engineering components: shafts, connecting rods, crankshafts, and bolts.
International equivalents
| Flag | Standard | Country | Grade | Number | Match |
|---|---|---|---|---|---|
| 🇺🇸 | AISI | USA | AISI 5135 | — | REF |
| 🇫🇷 | AFNOR | France | 38C4 | — | 95% |
Sources: ASTM A29, NF EN 10083-3
Chemical composition comparison (wt%)
Side-by-side: 37CrS4 (EN) (EN 10083-3:2006) vs 38C4 (AFNOR)
| Element | 37CrS4 (EN) | 38C4 (AFNOR) | Overlap |
|---|---|---|---|
| C | 0.34–0.41% | — | — |
| Si | ≤ 0.4% | — | — |
| Mn | 0.6–0.9% | — | — |
| P | ≤ 0.025% | — | — |
| S | 0.02–0.04% | — | — |
| Cr | 0.9–1.2% | — | — |
Mechanical properties
QT
| Property | Value | Unit |
|---|---|---|
| Tensile Strength | 900–1100 | MPa |
| Yield Strength | ≥ 700 | MPa |
| Elongation | ≥ 12 | % |
| impact_kv | ≥ 35 | J |
| Hardness HB | 270–330 | HB |
| Density | ≥ 7.85 | g/cm3 |
| Elastic Modulus | ≥ 210 | GPa |
Heat treatment
| Process | Temperature | Medium | Holding Time | Notes |
|---|---|---|---|---|
| quenching | 830–860 °C | oil | — | — |
| tempering | 540–680 °C | air | — | — |
| annealing | 680–720 °C | furnace | — | Soft annealing max 235 HB |
Compatibility verdict
37CrS4 and 38C4: 95% composition match
Close equivalents but NOT identical.
Related materials
33CrMoV12-9
1.8522Premium nitriding steel with high chromium content (2.8–3.3%) providing exceptional surface hardness after gas or plasma nitriding (up to 900 HV). Excellent core strength (900–1100 MPa tensile) with good toughness. Used for gears, crankshafts, cylinders, spindles, and precision machine components in aerospace, automotive, and power generation. Also known as 32CDV13 (AFNOR) and AMS 6481.
S235J2W
1.8961Entry-level structural weathering steel with minimum yield strength 235 MPa and impact testing at -20°C (J2 designation). Improved low-temperature toughness compared to S235J0W. Used for outdoor structural applications in colder climates where basic strength with atmospheric corrosion resistance is sufficient.
EN-GJS-500-7
5.3200Ferritic-pearlitic ductile cast iron with minimum tensile strength 500 MPa and minimum elongation 7%. The balanced grade offering significantly higher strength than EN-GJS-400-15 while retaining reasonable ductility. Mixed ferrite-pearlite matrix (typically 40-50% pearlite). Used for crankshafts, connecting rods, suspension components, gear housings, heavy-duty pipe fittings, and medium-stress structural castings. Equivalent to DIN GGG50, JIS FCD500.
Not sure which material fits?
🤖 Ask AI Advisor →All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.