Cr · Mo
42CrMo4 / 4140 QT round bars & blanks
Quenched and tempered (QT) round bars, cut QT blanks and machined blanks. Specify the governing standard, dimensions and inspection for your order.
Black / peeled / machined. Published range; confirm the size, property and surface combination in the quotation.
Supply formsQT round bars · Cut QT blanks · Machined blanks
Choose full-length QT round bars, cut blanks or machined blanks. Send the governing standard, dimensions, required properties, quantity and destination.
Specify mechanical properties for the ordered diameter and QT condition. The MTC example explains report fields; the certificate for your order must identify its own heat and test results.
Cross-references help compare grades; they do not establish interchangeability. The drawing standard, delivery condition, dimensions and inspection scope define the order.
Standard map
Supply window
Property requirements
| Supply stage | What arrives | Confirm before quotation |
|---|---|---|
| QT round bar | Quenched and tempered bars with the agreed black, peeled or machined surface. | Controlling grade standard; diameter and length; required properties and test basis; surface condition and straightness. |
| Cut QT blanks | QT bar cut to the blank length specified for the next manufacturing step. | Blank length and cutting tolerance; machining allowance; end preparation; heat or lot identification after cutting. |
| Machined blanks | Shaft, rod or pin blanks with rough or precision machining reviewed against the drawing. | Drawing revision; features and operations included; delivery tolerances; remaining allowance; property checks after the agreed process sequence. |
Specify the MTC and dimensional records for the ordered delivery stage. Agree test methods, sampling and acceptance criteria for any mechanical, hardness or UT requirements.
Heat treatment and surface finish can apply at more than one stage. State each separately in the RFQ.
State the required project standard first, then list acceptable cross-reference grades if they are allowed. This helps align chemistry, heat-treatment condition, mechanical properties, inspection, and certificate wording with the request.
Quenched and tempered 42CrMo4 or 4140 is a common option for high-load parts, but the required delivery condition should be stated by the buyer. Annealed, normalized, black, peeled, or machined routes may need separate review.
Common document requests include MTC, chemical composition, mechanical testing, heat number traceability, dimensional inspection, UT report if specified, third-party inspection if specified, packing list, and shipment documents.
Examples show a format; order documents must match your supply.
Ulrich, C., Günther, S., Becker, N. et al. High strength tempered 42CrMo4 for shafts in drive technology. Forschung im Ingenieurwesen 89, 59 (2025).
doi:10.1007/s10010-025-00818-x · CC BY 4.0
External research reference. Not a JOTAIN batch image. Panel cropped · original 10 µm scale retained.
Fig. 10 · 42CrMo4 · 560°C · SEM 2000× · 10 µm
42CrMo4 · include the supplied form, standard, size, condition, quantity and destination.
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