40Cr, SAE 5140, 41Cr4 and SCr440 Alloy Steel Bars

Short Answer for International Alloy Steel Buyers

Junxiong Metal can review and supply buyer-specified 40Cr, SAE 5140, 41Cr4 / 1.7035 and SCr440 alloy-steel bar enquiries in round, flat, square, hexagonal and drawing-based sections. Buyers should state the exact governing standard and edition, shape, dimensions, tolerance, delivery condition, downstream heat treatment, required properties, quantity, destination and MTC scope.

These designations are often compared in international sourcing, but they are not one universal specification. The purchase order and heat-specific MTC must control the accepted chemistry, product form, delivery condition, heat-treatment route and inspection requirements.

Send a complete 40Cr, 5140, 41Cr4 or SCr440 factory RFQ or send the standard, shape, size, condition and quantity by WhatsApp.

Representative Junxiong Alloy Steel Bar Shapes

Representative Junxiong cold drawn round steel bars with visible circular cross sections — Representative round-bar form. The photograph does not identify a 40Cr, 5140, 41Cr4 or SCr440 heat or batch.

Representative Junxiong cold drawn flat steel bars in multiple widths — Representative flat-bar form. Grade, condition and dimensional conformity require the approved order and matching batch documents.

Representative Junxiong cold drawn square steel bars with visible square cross sections — Representative square-bar form. Appearance cannot establish grade, heat-treatment condition or heat identity.

Representative Junxiong cold drawn hexagonal steel bars with six-sided cross sections — Representative hexagonal-bar form. Quote and acceptance remain subject to the exact standard, section and MTC.

Image boundary: these owner-supplied Junxiong photographs show relevant bar shapes only. They are not 40Cr, SAE 5140, 41Cr4 or SCr440 grade, stock, heat-treatment or batch evidence.

Supply Scope and Evidence Boundary

Junxiong has confirmed commercial supply capability for this chromium-alloy steel inquiry family. Exact feasibility is reviewed for the buyer’s named grade standard, section, size, incoming condition, downstream process, required properties, quantity and destination.

Evidence boundary: this page does not publish a matching heat-specific MTC, grade-specific shipment or current-stock record. Supply capability and representative photographs do not prove conformity of a future order. Batch acceptance requires the approved purchase specification, heat identity, matching MTC and agreed inspection records.

Do Not Approve These Grades by Alias Alone

Buyer search term	Specification route	Required control
40Cr steel	State the exact GB/T or buyer specification, edition and product form.	Chemistry, delivery condition, dimensions, surface, heat treatment, properties and MTC.
SAE 5140 steel	State the SAE chemistry route and the ordered cold-finished or other product specification.	Exact standard, product form, condition, dimensions, hardenability or property requirements and inspection.
41Cr4 / 1.7035 steel	State the ISO or buyer-adopted EN route and the required product/condition standard.	Grade, section, incoming condition, heat-treatment route, mechanical requirements and MTC.
JIS SCr440 steel	State JIS G 4053 and the required edition, product form and downstream process.	JIS designation, condition, dimensions, heat treatment, properties and inspection records.
Cross-standard comparison	Treat all four terms as inquiry and comparison routes, not automatic substitution approval.	Compare the actual ordered requirements and obtain written buyer approval before substitution.

SCr420 Steel, SNCM220 Steel and SNCM439 Steel under JIS G 4053

Short answer: Junxiong can review buyer-specified SCr420 steel, SNCM220 steel and SNCM439 steel enquiries, but each designation follows a separate JIS purchase route. The buyer must state the exact grade, JIS edition, product shape, supplied condition, downstream heat treatment, dimensions, tolerances, quantity, inspection scope and MTC requirement.

JIS buyer term	Controlled RFQ route	Boundary before quotation
SCr420 steel	Order the exact SCr420 designation under JIS G 4053:2026. Daido producer material places SCr420 in gear and shaft carburizing comparison contexts.	Do not relabel SCr420 as SCr440, SAE 5120, 20Cr4, 20Cr or another chromium-steel route. State carburizing or other heat-treatment requirements explicitly.
SNCM220 steel	Order the exact SNCM220 nickel-chromium-molybdenum designation under JIS G 4053:2026. Daido producer material includes an SNCM220 comparison route for carburizing gear applications.	Do not relabel SNCM220 as SCr420, SAE 8620, 20NiCrMo2-2 or SNCM439. The ordered chemistry, supplied condition, hardenability or required properties, and heat-specific MTC govern acceptance.
SNCM439 steel	Order the exact SNCM439 nickel-chromium-molybdenum designation under JIS G 4053:2026. Nippon Steel and Aichi Steel public producer ranges list SNCM439 within the JIS machine-structural alloy family.	Do not relabel SNCM439 as SAE 4340, SNCM220 or another Ni-Cr-Mo grade. State the incoming and final heat-treatment route, required properties and test-piece requirements.
Product route	The JSA scope describes material mainly made by hot rolling, hot forging or hot extrusion in a uniform cross section and normally used after further forging, machining or heat treatment.	A cold-drawn, peeled, turned, ground or other finished-bar enquiry needs its own product route, dimensions, surface, straightness and acceptance criteria; the grade standard alone is insufficient.
H-grade suffix	SCr420H and SNCM220H are hardenability-guaranteed designations controlled separately under JIS G 4052.	Do not add or remove the H suffix without the buyer’s exact standard and written approval.

Evidence boundary: the JSA standard record and Japanese producer catalogues support designation, scope and producer context. They do not prove Junxiong current stock, a matching cold-drawn finished-bar heat, grade-specific photographs, shipment history or a public batch MTC.

Send the exact SCr420, SNCM220 or SNCM439 specification for factory review.

Technical Facts Buyers Must Confirm

Decision	RFQ information required
Grade route	40Cr, SAE 5140, 41Cr4 / 1.7035, SCr440 or another buyer-approved designation, plus standard and edition.
Product route	Cold drawn, bright drawn, peeled/turned, ground, hot rolled, forged or another specified route. Do not use one product standard for every form.
Delivery condition	State annealed, normalized, quenched and tempered, cold-finished or another agreed condition, including incoming hardness where applicable.
Dimensions	Shape, diameter or full section, tolerance, straightness, twist or flatness, corner/edge form, length and machining allowance.
Downstream process	State machining, induction hardening, through hardening, tempering, grinding, plating or other buyer-controlled operations.
Performance route	State required hardness, tensile/yield properties, impact, hardenability or component validation and test-piece location.
Inspection	Heat identity, MTC type, chemistry, mechanical properties, hardness, surface, decarburization and supplementary inspection requirements.
Commercial data	Quantity per size, trial and annual demand, packing, destination country, port and delivery schedule.

Shape and RFQ Selection

Shape	Buyer must state	Factory review
Round bar	Diameter, tolerance, straightness, surface, length, condition and later machining or heat treatment.	Starting material, reduction route, condition, inspection, MOQ and schedule for the exact grade-size combination.
Flat bar	Width, thickness, edge condition, flatness, straightness, surface and length.	Feasibility depends on grade, starting section, reduction, tooling, surface controls, condition and quantity.
Square bar	Side size, tolerance, corner radius, twist, straightness, condition and length.	Feasibility depends on grade, starting section, reduction, tooling, surface controls and quantity.
Hexagonal bar	Across-flats size, tolerance, corner form, twist, straightness, condition and length.	Feasibility depends on grade, starting section, reduction, tooling, surface controls and quantity.
Custom profile	Dimensioned drawing, datums, critical tolerances, radii, condition, annual demand and trial quantity.	Drawing review covers material flow, tooling, first-article inspection, heat-treatment allowance and downstream use.

Standards and Primary Reference Sources

GB/T 3077-2015: China’s official national-standard record lists the alloy structural steel standard as current. The order must still identify the grade, product form, condition and inspection requirements.
SAE J404 revision record: the SAE publisher page identifies J404_200901 as the verified revision for SAE alloy-steel chemical compositions.
JIS G 4053:2026: the current JSA record for low-alloyed steels for machine structural use. Its stated scope is not a substitute for a separately ordered cold-finished product route.
Nippon Steel bars and wire rods catalogue: current producer material that lists SCr420, SNCM220 and SNCM439 under the JIS G 4053 machine-structural alloy-steel family.
Daido Steel manufacturing-grade range: producer context for JIS G 4053 SCr and SNCM families and bar/wire-rod ranges; it is not Junxiong stock evidence.
Daido Steel gear and shaft material guide: application context for separately controlled SCr420 and SNCM220 carburizing routes.
Aichi Steel machine-structural alloy range: producer context covering SCr415-SCr445 and SNCM220-SNCM815 under JIS G 4053.
ISO 683-2:2016: the current ISO technical-delivery route for alloy steels for quenching and tempering. ISO notes that this part does not cover bright products.
ISO 683-7:2023: the current ISO technical-delivery route for bright products in drawn, peeled/turned or additionally ground condition.
Swiss Steel Group 41Cr4 / 1.7035 data sheet: a producer reference that lists SCr440 as an international designation for its 41Cr4 route. It does not list 40Cr or SAE 5140 as automatic equivalents.

Reference boundary: publisher and producer pages support terminology, scope and buyer verification. They are not Junxiong heat certificates and do not prove automatic equivalence, current stock or conformity of a delivered batch.

Typical Buyer Applications

Machined shafts, axles, pins, couplings and sleeves.
Gears, sprockets, fastener and transmission components.
Induction-hardened or quenched-and-tempered machinery parts.
Cold-drawn flats, squares, hexagons and special sections used as machining blanks.

Application suitability depends on the exact standard, section size, delivery condition, heat-treatment process, loading, surface quality and finished-component validation. The buyer remains responsible for final grade and process approval.

Buyer Checklist Before Quotation

Exact grade designation, governing standard and standard edition.
Shape, finished dimensions and machining or heat-treatment allowance.
Dimensional tolerance, straightness, twist, flatness, corner/edge and length limits.
Incoming delivery condition and downstream hardening/tempering route.
Surface, decarburization and defect limits with inspection method.
Required hardness, mechanical properties, hardenability or component validation.
MTC, heat traceability and third-party inspection requirements.
Quantity per size, annual demand, destination, schedule and packing.

FAQ for 40Cr, 5140, 41Cr4 and SCr440 Buyers

Are 40Cr, SAE 5140, 41Cr4 and SCr440 exactly the same steel?

No automatic equivalence is assumed. They are cross-market inquiry terms. The ordered chemistry, product standard, condition, dimensions, heat treatment, properties and MTC control acceptance.

Can Junxiong supply cold-drawn round, flat, square and hexagonal bars?

Junxiong can review these shapes and drawing-based profiles after confirming the exact grade standard, dimensions, condition, tooling, surface controls, quantity and destination.

Which standard applies to a bright or cold-drawn bar?

The grade chemistry route and the bright-product technical-delivery route must both be identified. ISO 683-2:2016 covers alloy steels for quenching and tempering but explicitly excludes bright products; ISO 683-7:2023 covers bright products.

Can a representative photograph prove 40Cr or 5140?

No. Bar shape and appearance cannot establish grade, heat identity or delivery condition. The approved purchase specification and matching heat-specific documents are required.

What information is needed for a useful factory quotation?

Send the exact grade and standard, shape, dimensions, tolerance, delivery condition, heat-treatment plan, inspection scope, quantity, annual demand, destination and application.

Are SCr420 steel, SNCM220 steel and SNCM439 steel interchangeable?

No. They are separate JIS G 4053 designations with different alloy routes and downstream decisions. The exact grade, standard edition, condition, heat-treatment plan, required properties and matching MTC must control the order.

Does JIS G 4053 automatically define a cold-drawn steel bar?

No. The current JSA scope describes primarily hot-rolled, hot-forged and hot-extruded machine-structural alloy steel. A cold-drawn or other cold-finished order needs separately agreed product-route, dimensional, surface, straightness and inspection requirements.

Related Alloy and Cold Drawn Steel Pages

Send the complete 40Cr, 5140, 41Cr4 or SCr440 specification for factory review.