VT machining offers CNC Turning for Q345 Steel (GB/T 1591 (now Q355) / ~S355JR), typically supplied hot-rolled. Chinese low-alloy high-strength steel; replaced by Q355 in GB/T 1591-2018.
CNC Turning Notes for Q345 Steel
Q345 Steel turns with good chip control at standard cutting data.
For estimating, a 100 × 100 × 10 mm block of Q345 Steel weighs about 0.79 kg.
Starting Parameters for CNC Turning Q345 Steel
| Cutting speed (carbide) | 185-325 m/min |
|---|---|
| Feed | 0.1-0.35 mm/rev |
| Spindle speed, Ø25 mm bar | 2360-4140 rpm |
| Insert / tool class | ISO P — CVD-coated carbide |
| Coolant | Emulsion (5-8%); dry is possible for interrupted cuts |
Starting values for Q345 Steel, Hot-rolled; optimised on the first article.
Q345 Steel Data Relevant to CNC Turning
| Equivalent designations | GB/T 1591 (now Q355) / ~S355JR |
|---|---|
| Key composition | C ≤0.20%, Mn ≤1.7% |
| 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 Q345 Steel Differs
Chinese low-alloy high-strength steel; replaced by Q355 in GB/T 1591-2018.
Typical applications: Bridges, machine bases, pressure parts.
Q345 Steel vs Similar Grades
| Q345 Steel | Q235 Steel | SPCC Steel | S355JR Steel | |
|---|---|---|---|---|
| Key composition | C ≤0.20%, Mn ≤1.7% | C ≤0.22%, Mn ≤1.4% | C ≤0.15% | C ≤0.24%, Mn ≤1.6% |
| Hardness | ~150 HB | ~120 HB | ~50-65 HRB | ~150 HB |
| Tensile (MPa) | 470-630 | 370-500 | ≥270 | 470-630 |
| Machinability % | 65 | 70 | 55 | 65 |
| Typical use | Bridges, machine bases, pressure parts | Frames, plates, general fabrications | Sheet-metal enclosures, brackets, panels | Machine frames, heavy brackets, cranes |
More on CNC Turning Steel
Finishing options, quality documentation and general cnc turning guidance for all steel grades are on our CNC Turning Steel page.
No drawing yet? Sketch the part in our free 3D + 2D builder and send it with your RFQ.
Quoting CNC Turning Q345 Steel
Send a STEP/IGES model or PDF drawing, confirm Q345 Steel and its condition (we usually see it supplied hot-rolled), the quantity, critical tolerances and any finish or certificate requirements.
Q345 Steel in Other Processes
Related
Send the drawing, the Q345 Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
What material thickness or size range suits CNC Turning Q345 Steel?
Turned Q345 Steel parts are produced from bar or chuck stock across a wide diameter range.
What is the typical lead time and minimum order for CNC Turning Q345 Steel?
CNC Turning prototypes for Q345 Steel can be produced quickly and scaled to series production. Send your drawing and quantity and we will advise lead time and any minimum order.
Why is Q345 Steel a good choice for CNC Turning?
Q345 Steel is strong, economical and widely available, which makes it well suited to CNC Turning. We tune the process to the alloy so the finished Q345 Steel turning part meets your dimensional and functional requirements.
What surface finish is achievable on Q345 Steel with CNC Turning?
Surface finish on Q345 Steel is controlled to your specification; we confirm the achievable Ra against your callout.
Can VT machining make custom Q345 Steel parts to my drawing?
Yes. Q345 Steel turning 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.