VT machining offers CNC Turning for 42CrMo Steel (GB/T 3077 / ~4140 / 42CrMo4), typically supplied Q&T. Chinese equivalent of 4140/42CrMo4.
CNC Turning Notes for 42CrMo Steel
42CrMo Steel turns with good chip control at standard cutting data.
For estimating, a 100 × 100 × 10 mm block of 42CrMo Steel weighs about 0.79 kg.
Starting Parameters for CNC Turning 42CrMo Steel
| Cutting speed (carbide) | 140-250 m/min |
|---|---|
| Feed | 0.1-0.35 mm/rev |
| Spindle speed, Ø25 mm bar | 1780-3180 rpm |
| Insert / tool class | ISO P — CVD-coated carbide |
| Coolant | Emulsion (5-8%); dry is possible for interrupted cuts |
Starting values for 42CrMo Steel, Q&T; optimised on the first article.
42CrMo Steel Data Relevant to CNC Turning
| Equivalent designations | GB/T 3077 / ~4140 / 42CrMo4 |
|---|---|
| Key composition | C 0.38-0.45%, Cr 0.9-1.2%, Mo 0.15-0.25% |
| Typical supply condition | Q&T |
| Hardness (typical) | ~28-32 HRC |
| Machinability rating | 62% (AISI B1112 = 100%) |
Typical values; we work to your drawing and mill certificate.
How 42CrMo Steel Differs
Chinese equivalent of 4140/42CrMo4.
Typical applications: Gears, shafts, high-strength bolts.
42CrMo Steel vs Similar Grades
| 42CrMo Steel | 40Cr Steel | 20CrMnTi Steel | EN19 Steel | |
|---|---|---|---|---|
| Key composition | C 0.38-0.45%, Cr 0.9-1.2%, Mo 0.15-0.25% | C 0.37-0.44%, Cr 0.8-1.1% | C 0.17-0.23%, Cr 1-1.3%, Mn 0.8-1.1%, Ti | C 0.36-0.44%, Cr 0.9-1.2%, Mo 0.25-0.35% |
| Hardness | ~28-32 HRC | ~28-32 HRC | ~58-62 HRC case | ~28-32 HRC |
| Tensile (MPa) | ~1080 Q&T | ~980 Q&T | ~1080 core | ~850-1000 |
| Machinability % | 62 | 60 | 60 | 62 |
| Typical use | Gears, shafts, high-strength bolts | Shafts, gears, bolts | Automotive gears, shafts | Shafts, gears, studs |
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 42CrMo Steel
Send a STEP/IGES model or PDF drawing, confirm 42CrMo Steel and its condition (we usually see it supplied Q&T), the quantity, critical tolerances and any finish or certificate requirements.
42CrMo Steel in Other Processes
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Send the drawing, the 42CrMo Steel condition and the quantity — pricing and lead time come back the same or next business day.
Request a QuoteFrequently Asked Questions
What is the typical lead time and minimum order for CNC Turning 42CrMo Steel?
CNC Turning prototypes for 42CrMo 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.
Does CNC Turning 42CrMo Steel require dedicated tooling?
Most 42CrMo Steel turning work uses standard cutting tools and CNC programs; dedicated fixtures are made only when geometry or volume requires them.
What surface finish is achievable on 42CrMo Steel with CNC Turning?
Surface finish on 42CrMo Steel is controlled to your specification; we confirm the achievable Ra against your callout.
What material thickness or size range suits CNC Turning 42CrMo Steel?
Turned 42CrMo Steel parts are produced from bar or chuck stock across a wide diameter range.
Can VT machining make custom 42CrMo Steel parts to my drawing?
Yes. 42CrMo 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.