Grade Designations.
| BS EN 10083-3:2006 | 34CrMo4 / 1.7220 |
| BS 970:1991 (withdrawn) | 605M36 |
| AISI/SAE | 4135 |
| DIN | 34CrMo4 / 1.7220 |
| ISO | 34CrMo4 |
Availability & Supply Condition.
Bright Rounds: 8–100mm | Black Rounds: 25–150mm
Supply condition: Bright Drawn or Hot Rolled Black. Supplied normalised or as-drawn.
Cut to length from 1 piece — −0/+2mm standard tolerance — 2–3 day turnaround — Cutting service details ›
Chemical Analysis.
Values shown as percentages by weight (% wt). Values are ranges unless stated as maxima.
| Designation | C | Si | Mn | P max | S max | Cr | Mo |
|---|---|---|---|---|---|---|---|
| 605M36 | 0.30–0.40 | 0.10–0.35 | 0.70–1.00 | 0.04 | 0.04 | 0.90–1.20 | 0.25–0.35 |
| 34CrMo4 | 0.30–0.37 | 0.17–0.37 | 0.60–0.90 | 0.035 | 0.035 | 0.90–1.20 | 0.15–0.30 |
For full chemical analysis with heat number, request an EN 10204 3.1 material test certificate when ordering — available on all alloy grades. Certificate types explained ›
Mechanical Properties.
Values shown for standard supply condition. Properties vary by section size and heat treatment condition.
| Condition | Size (mm) | Tensile Rm (N/mm²) | Yield Re (N/mm²) | A% min |
|---|---|---|---|---|
| H&T (T) | ≤16 / >16–40 / >40–63 | 900–1100 / 800–950 / 700–850 | ≥700 / ≥600 / ≥500 | 12 / 13 / 14 |
Hardness values: see our hardness conversion table to convert between HRC, HB, HV and tensile strength.
Typical Applications.
- Feedstock for bright bar cold drawing
- Engineering shafts and spindles (medium duty)
- Axles and transmission components
- High-tensile bolting and studs
- Oil and gas downhole components
Key Benefits.
- Better hardenability than plain carbon EN8
- Good response to heat treatment in larger sections
- Lower cost than EN19 for medium-duty applications
- Good machinability in annealed or normalised condition
Remarks & Guidance.
Preheat to 200–300°C before welding. Post-weld heat treatment recommended. For hardening and tempering: oil quench from 850–880°C and temper at 550–660°C. For normalising: heat to 850–870°C and air cool.
Relevant Heat Treatment Processes.
This grade responds to the following heat treatment processes. Click any card for temperatures, cooling methods and expected hardness values.
Normalising refines grain structure and relieves stress after forging or machining.
This grade responds to quench hardening — oil or water quench from austenitising temperature.
Temper after hardening to achieve the required tensile range and reduce brittleness.
