CNC Gear Grinding Alloy Steel

VT machining provides CNC Gear Grinding Alloy Steel for customers who need accurate, repeatable Alloy Steel components. Because Alloy Steel is high strength and hardenability for demanding parts, we adapt the process to suit — controlling the variables that matter for this alloy.

CNC Gear Grinding Alloy Steel at VT machining
CNC Gear Grinding Alloy Steel — produced in-house at VT machining

CNC Gear Grinding Capability for Alloy Steel

  • DIN/AGMA accuracy class
  • Profile & lead correction
  • Hardened-gear finishing
  • Low transmission noise

Alloy Steel Material Data

Alloy Steel — typical properties, quoted for 4140 (Q&T)
Density7.85 g/cm³
Tensile strength655–1020 MPa
Yield strength (0.2%)415–900 MPa
Hardness197–302 HB
Melting point1416 °C
Thermal conductivity42.6 W/m·K
Thermal expansion12.3 ×10⁻⁶/K
Electrical conductivity8%
Machinability (C36000 = 100%)65% (annealed)
Grades we run4140, 4340, 8620, 20CrMnTi, 42CrMo4, 20MnCr5

Published typical values for 4140 (Q&T). Other grades in the family differ — the certificate supplied with your order carries the actual heat-lot figures.

Machining Alloy Steel — what actually causes trouble

Heat treatment moves the part. Anything held tighter than ±0.02 mm is machined soft, hardened, then ground or hard-turned to final size.

How CNC Gear Grinding Alloy Steel Works

Tooth profiles are generated in the Alloy Steel blank by a synchronised cutter, then refined to the required accuracy class. Module, pressure angle and helix are programmed from your gear data.

We start from your supplied geometry and tolerance scheme. The setup is designed to minimise re-clamping, which protects positional accuracy across features. A first article is verified against the drawing before the balance of the batch is released.

Achievable Tolerances for CNC Gear Grinding Alloy Steel

CNC Gear Grinding Alloy Steel — achievable tolerances
FeatureStandardPrecision
Accuracy classDIN 8 / AGMA 10DIN 6 / AGMA 12
Profile deviation0.020 mm0.008 mm
Lead deviation0.020 mm0.008 mm
Pitch deviation (cumulative)0.040 mm0.015 mm
Runout0.030 mm0.010 mm
Tooth surface finishRa 1.6 µmRa 0.4 µm (ground)
Module rangem0.5–m8m1–m6

Standard is what a normal quotation assumes. Precision is available on nominated features and is priced separately, because it needs extra setups, in-process gauging and CMM verification. Call out only the features that need it — blanket-tightening a drawing is the single most common reason a quote comes back expensive.

Working with Alloy Steel

Alloy Steel is high strength and hardenability for demanding parts. We translate those properties into a process plan: the right tooling, speeds, feeds and fixturing for the alloy.

Where the grade, temper or heat-treat condition matters to performance, we confirm it with you and can supply material certificates. Material is procured to recognised standards for consistent, repeatable results.

Design Tips for CNC Gear Grinding Alloy Steel

Small design adjustments often cut cost and lead time. Providing complete gear data (module, pressure angle, profile shift, quality class) lets us produce Alloy Steel gears right the first time. If you send your model early, we will return practical DFM feedback before you commit to production.

CNC Gear Grinding Tolerances & Surface Finish

Gear features are produced to a specified DIN/AGMA accuracy class, with profile and lead controlled for quiet, durable running under load.

The tightest tolerances are reserved for the features your drawing flags as critical. Share your tolerance scheme and we will confirm what is realistic before quoting.

CNC Gear Grinding Quality & Inspection

Quality is built in, not inspected on. We monitor key features during the run and confirm them at final inspection, with CMM verification available for tight tolerances. We provide the inspection and traceability records your quality system requires.

Secondary Operations & Finishing

Most Alloy Steel parts need some finishing, which we manage in-house or through vetted partners. Options include deburring and edge-breaking, heat treatment, surface grinding, polishing, and plating or anodising for corrosion resistance and appearance. Give us the finished-part requirement and we will sequence every operation correctly.

Applications of CNC Gear Grinding Alloy Steel

Alloy Steel parts made this way are found throughout aerospace, medical, automotive, electronics and industrial equipment. Prototype, bridge and production volumes are all welcome.

How to Order CNC Gear Grinding Alloy Steel

Starting your project takes one email. Send your CAD or 2D drawing, the Alloy Steel grade and condition, the quantity and any finish or inspection requirements. We respond quickly with price, lead time and any DFM notes, in clear English.

Parts We Have Run in Alloy Steel

Three representative CNC Gear Grinding Alloy Steel jobs, with the callouts that actually drove the process plan. Yours will differ — these are here so you can judge whether your part is in our range before you spend time on an RFQ.

Internal ring gear

Material
Alloy Steel
Size
m2.5, z72, ID 190 mm
Key callouts
DIN 8, pitch deviation 0.03 mm
Batch
150 pcs

Shaped rather than hobbed — an internal gear leaves no room for a hob to run out.

Worm and wheel set

Material
Alloy Steel
Size
m3, single start
Key callouts
Backlash 0.05–0.10 mm as a matched pair
Batch
120 sets

Supplied as matched sets and marked, because mixing pairs loses the backlash spec.

Helical pinion

Material
Alloy Steel
Size
m1.5, z18, 15° helix
Key callouts
DIN 6, lead deviation 0.008 mm
Batch
300 pcs

Ground after case hardening to 58 HRC at 0.6 mm case depth.

Finishing Options for Alloy Steel

Finishing options available with this material
FinishThickness / effectWhy it gets specified
Through hardening30–55 HRC, ground afterwards for tight sizes
Case hardening (carburise)0.3–1.2 mm case58–62 HRC surface, tough core
Nitride0.1–0.5 mm900–1100 HV, minimal distortion
Black oxide1–2 µmCosmetic + light corrosion protection
Zinc / nickel plate5–25 µmCorrosion protection
Deburr / edge break0.05–0.3 mmAll parts unless the drawing says otherwise
Bead blastRa 1.6–3.2 µmUniform matt finish, hides tool marks
Laser markingPart number, lot code, data matrix
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No drawing yet? Build one in the browser.

Set the metal, dimensions and features, watch the 3D model update as you type, then switch to the 2D sheet to add dimensions and tolerances. Download it or send it straight to us with your RFQ.

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What We Need to Quote CNC Gear Grinding Alloy Steel

  • GeometrySTEP or IGES for the 3D model, plus a PDF drawing if you have tolerance callouts. A dimensioned sketch is enough to start.
  • MaterialThe exact Alloy Steel grade and condition — temper, heat-treat state or hardness. If you are not sure, tell us the function and we will suggest one.
  • QuantityPrototype count and the expected annual volume. Both change how the part is made and therefore what it costs.
  • TolerancesWhich features are critical. Everything else runs to our standard tolerance, which is what keeps the price sensible.
  • FinishSurface treatment, cosmetic requirements, and any faces that must be masked.
  • DocumentsWhether you need a material certificate, dimensional report, FAIR or PPAP with the shipment.

Missing something from the list is not a problem — send what you have. We will come back with the specific questions rather than a generic form.

Other Metals for CNC Gear Grinding

Other Processes for Alloy Steel

Send the drawing, the Alloy Steel grade and the quantity. You get pricing, lead time and any DFM notes back — usually within one business day.

Request a Quote

Frequently Asked Questions

What material thickness or size range suits CNC Gear Grinding Alloy Steel?

We machine Alloy Steel across a broad size range; share your part envelope for confirmation.

What gear accuracy class can you achieve on Alloy Steel?

Gear accuracy is specified to DIN/AGMA classes appropriate to the application. Profile and lead are controlled so Alloy Steel gears run accurately and quietly under load.

What is the typical lead time and minimum order for CNC Gear Grinding Alloy Steel?

CNC Gear Grinding prototypes for Alloy 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.

What tolerances can you hold for CNC Gear Grinding Alloy Steel?

Achievable tolerances for Alloy Steel gear cutting depend on the alloy, geometry and feature size. We hold tight, repeatable tolerances appropriate to the feature and material. Exact figures are confirmed against your drawing callouts.