VT machining offers CNC Milling for S355JR Steel (EN 10025 / 1.0045 / ~Q345B), typically supplied hot-rolled. Higher-strength structural steel, yield ≥355 MPa.
CNC Milling Notes for S355JR Steel
S355JR Steel mills well with conventional strategies; finishing passes are planned to meet flatness and finish callouts.
For estimating, a 100 × 100 × 10 mm block of S355JR Steel weighs about 0.79 kg.
Starting Parameters for CNC Milling S355JR Steel
| Cutting speed (carbide) | 160-275 m/min |
|---|---|
| Feed per tooth | 0.035-0.123 mm |
| Spindle speed, Ø10 mm end mill | 5090-8750 rpm |
| Insert / tool class | ISO P — CVD-coated carbide |
| Coolant | Emulsion (5-8%); dry is possible for interrupted cuts |
| Thermal growth, 100 mm part, +10 °C | 11.7 µm (CTE 11.7 µm/m·K) |
Starting values for S355JR Steel, Hot-rolled; optimised on the first article.
S355JR Steel Data Relevant to CNC Milling
| Equivalent designations | EN 10025 / 1.0045 / ~Q345B |
|---|---|
| Key composition | C ≤0.24%, Mn ≤1.6% |
| Typical supply condition | Hot-rolled |
| Hardness (typical) | ~150 HB |
| Machinability rating | 65% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How S355JR Steel Differs
Higher-strength structural steel, yield ≥355 MPa.
Typical applications: Machine frames, heavy brackets, cranes.
S355JR Steel vs Similar Grades
| S355JR Steel | S275JR Steel | Q235 Steel | S235JR Steel | |
|---|---|---|---|---|
| Key composition | C ≤0.24%, Mn ≤1.6% | C ≤0.21%, Mn ≤1.5% | C ≤0.22%, Mn ≤1.4% | C ≤0.17-0.20%, Mn ≤1.4% |
| Hardness | ~150 HB | ~130 HB | ~120 HB | ~120 HB |
| Tensile (MPa) | 470-630 | 410-560 | 370-500 | 360-510 |
| Machinability % | 65 | 70 | 70 | 70 |
| Typical use | Machine frames, heavy brackets, cranes | Structural sections, base plates | Frames, plates, general fabrications | Frames, brackets, weldments |
More on CNC Milling Steel
Finishing options, quality documentation and general cnc milling guidance for all steel grades are on our CNC Milling Steel page.
No drawing yet? Sketch the part in our free 3D + 2D builder and send it with your RFQ.
Quoting CNC Milling S355JR Steel
Send a STEP/IGES model or PDF drawing, confirm S355JR Steel and its condition (we usually see it supplied hot-rolled), the quantity, critical tolerances and any finish or certificate requirements.
S355JR Steel in Other Processes
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Send the drawing, the S355JR Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
Can VT machining make custom S355JR Steel parts to my drawing?
Yes. S355JR Steel machining is made to order from your CAD/2D drawing. Share your geometry, material grade, tolerance and quantity and we will confirm feasibility, lead time and pricing.
What surface finish is achievable on S355JR Steel with CNC Milling?
Surface finish on S355JR Steel is controlled to your specification; we confirm the achievable Ra against your callout.
What tolerances can you hold for CNC Milling S355JR Steel?
Achievable tolerances for S355JR Steel machining depend on the alloy, geometry and feature size. Milling holds positional and dimensional tolerances to around ±0.01 mm, tighter with precision setups. Exact figures are confirmed against your drawing callouts.
What is CNC Milling S355JR Steel and how is it done?
CNC Milling S355JR Steel refers to multi-axis milling cutters remove material to produce prismatic features, pockets, slots and contoured 3D surfaces. Applied to S355JR Steel — strong, economical and widely available — VT machining produces each part to your CAD drawing, selecting parameters from your tolerance, finish and quantity requirements.
Does CNC Milling S355JR Steel require dedicated tooling?
Most S355JR Steel machining work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
Which industries use CNC Milling S355JR Steel parts?
CNC Milling S355JR Steel parts are used across aerospace, medical, automotive, electronics, semiconductor and general industrial sectors — anywhere precise S355JR Steel components are required.