6150 and 51CrV4 Spring Steel Bars
Short Answer for 6150 Steel, 51CrV4 Steel and SUP10 Steel Buyers
Junxiong Metal can supply and review SAE 6150 and 51CrV4 spring-steel bar enquiries in round, flat, square, hexagonal and drawing-based sections. A separate SUP10 enquiry route is also available under the buyer’s specified JIS requirements. Buyers should state the governing standard and edition, product form, dimensions, tolerance, supplied condition, downstream forming and heat-treatment route, required properties, surface and decarburization limits, quantity, destination and MTC scope.
SAE 6150, 51CrV4, 1.8159 and SUP10 belong to related spring-steel sourcing tasks, but they are not one universal specification or automatic substitutes. The purchase order must control the accepted standard, chemistry, product form, incoming condition, heat treatment, mechanical properties, surface quality and inspection route.
Send a complete 6150, 51CrV4 or SUP10 factory RFQ or send the grade, standard, shape, size, condition and quantity by WhatsApp.
Representative Spring Steel Bar Shapes
Image boundary: spring-steel grade and heat-treatment condition cannot be verified from appearance. These images do not identify a 6150, 51CrV4, 1.8159 or SUP10 heat or batch. The owner-supplied Junxiong photographs show relevant round and flat cold-drawn bar forms only and are not grade, hardness, fatigue-life or conformity evidence.
Supply Scope and Evidence Boundary
Junxiong has confirmed commercial supply capability for this spring-steel family. Exact feasibility is reviewed for the buyer’s grade standard, section, dimensions, incoming condition, heat-treatment route, property requirements, quantity and destination.
Evidence boundary: the current local archive does not contain a public-ready 6150, 51CrV4 or SUP10 grade-specific product photograph, shipment record or MTC. A capability statement and representative images do not prove current stock, a particular heat, spring performance or conformity of another order. Matching order and batch documents are required before this page can be considered for paid traffic.
Do Not Approve 6150, 51CrV4 or SUP10 by Alias Alone
| Search or specification term | Buyer verification route | What must be controlled |
|---|---|---|
| SAE 6150 | Use the buyer’s named SAE chemistry route and the ordered cold-finished or other product specification. | Exact chemistry standard, product form, supplied condition, dimensions, surface, decarburization, heat treatment and properties. |
| 51CrV4 / 1.8159 | Use the buyer’s named EN grade and spring-steel product route, including the required edition. | Grade and product standard, section, incoming condition, hardening and tempering route, properties, surface and inspection. |
| SUP10 | Use the buyer’s exact JIS grade and standard edition. JIS G 4801:2021 is the current JSA-listed spring-steel route. | Do not infer SAE 6150, 51CrV4 or 1.8159 substitution from application similarity or an unofficial equivalence table. |
| 6150 versus 51CrV4 | Treat the names as comparison and inquiry routes, not an automatic substitution approval. | Compare the actual ordered chemistry, product form, condition, dimensions, heat-treatment response and acceptance criteria. |
SUP10 Steel RFQ Route under JIS G 4801
Short answer: buyers searching for SUP10 steel can submit an RFQ under the exact SUP10 designation and the required JIS G 4801 edition. JSA lists JIS G 4801:2021 as valid and describes its scope as spring steels mainly used for hot-formed laminated springs, coil springs and torsion bars. Its product forms include round bars and flat bars, as well as wire-related and flat-product forms.
| Control point | What the buyer must specify |
|---|---|
| Designation and standard | Write SUP10 and the governing JIS G 4801 edition on the enquiry and purchase order. Do not replace it with SAE or EN shorthand. |
| Product form | For the JIS G 4801 route, identify round bar or flat bar and state whether the required material is hot-rolled, later cold-finished or otherwise processed. The spring-grade standard alone does not define a cold-drawn finish. |
| Non-standard shape request | Square, hexagonal or drawing-based sections require a separate buyer-approved product route, dimensioned drawing and factory feasibility review; they are not inferred from JIS G 4801. |
| Dimensions and condition | Diameter or width and thickness, tolerance, length, straightness or flatness, surface condition, incoming condition, hardness and machining or forming allowance. |
| Spring duty | Downstream hot or cold forming, hardening and tempering, decarburization limits, required properties, fatigue-validation responsibility and final component acceptance criteria. |
| Evidence and commercial scope | Heat identity, MTC and test requirements, quantity per size, annual demand, destination and packing. This page does not claim current SUP10 stock or a matching Junxiong batch. |
Producer-reference boundary: Daido Steel publicly identifies SUP10 as a spring-steel strip grade and publishes representative chemistry, while Aichi Steel states that its JIS G 4801 spring-steel range includes SUP6 through SUP13. Those producer pages support designation and application context only. Daido’s strip program does not prove Junxiong bar availability, and neither source is a Junxiong heat certificate or substitution approval.
Technical Facts Buyers Must Confirm
| Decision | Required RFQ information |
|---|---|
| Grade route | SAE 6150, 51CrV4, 1.8159, SUP10 or another buyer-approved spring-steel designation, plus the governing standard and edition. |
| Supplied condition | State annealed, normalized, cold-finished or another approved condition, including incoming hardness where applicable. |
| Downstream process | State cold or hot forming, machining, hardening, tempering, shot peening, grinding or other buyer-controlled operations that affect material and allowance decisions. |
| Surface and decarburization | State surface-defect, scale, decarburization and machining or grinding allowance requirements, plus the inspection method and limits. |
| Performance route | State required hardness, tensile or yield properties, toughness, fatigue validation and the test-piece location after the agreed process. |
| Inspection | Heat identity, MTC type, chemistry, mechanical properties, hardness, grain size, macrostructure or supplementary inspection requirements. |
| Commercial data | Quantity per size, repeat demand, packing, destination country, port and required delivery schedule. |
Shape and RFQ Selection
| Shape | Buyer must state | Factory review |
|---|---|---|
| Round bar | Diameter, tolerance, straightness, surface, length and machining or later forming requirements. | Starting material, reduction route, incoming condition, inspection, MOQ and schedule are reviewed for the exact grade-size-condition combination. |
| Flat bar | Width, thickness, edge condition, flatness, straightness, surface/decarburization limits and length. | Starting material, reduction route, incoming condition, inspection, MOQ and schedule are reviewed for the exact grade-size-condition combination. |
| Square bar | Side size, tolerance, corner radius, twist, straightness and length. | Feasibility depends on the ordered grade, incoming condition, section reduction, tooling, surface controls and quantity. |
| Hexagonal bar | Across-flats size, tolerance, corner form, twist, straightness and length. | Feasibility depends on the ordered grade, incoming condition, section reduction, tooling, surface controls and quantity. |
| Custom profile | Dimensioned drawing, datums, critical tolerances, radii, annual demand and trial quantity. | Drawing review must cover material flow, surface/decarburization controls, first-article inspection and downstream spring processing. |
Standards and Primary Reference Sources
- SAE J404 revision record: the SAE publisher page identifies J404_200901 as the verified revision for SAE alloy-steel chemical compositions. The order must state the required edition.
- ASTM A108-24: the active ASTM specification route for carbon and alloy cold-finished steel bars. It does not by itself guarantee spring fatigue performance.
- BS EN 10089:2002: the current BSI-listed technical-delivery route for hot-rolled steels intended for quenched-and-tempered springs. A cold-finished section still requires its separate ordered product-form and dimensional controls.
- BS EN 10277:2018: the BSI technical-delivery reference for bright steel products; coverage and the exact ordered grade/product route must be verified rather than assumed.
- Ovako 51CrV4 material data: a producer reference listing AISI 6150 and 1.8159 as similar designations. Similar designations are not automatic equivalents.
- JIS G 4801:2021: the current JSA-listed spring-steel standard for primarily hot-formed spring applications, with product forms that include round and flat bars.
- Daido Steel SUP10 producer data: designation, spring-steel strip and representative-composition context; not Junxiong bar, stock or batch evidence.
- Aichi Steel spring-steel program: producer confirmation that its JIS G 4801 range includes SUP6 through SUP13, subject to current order acceptance.
Reference boundary: publisher and producer pages support terminology and buyer verification. They are not Junxiong heat certificates and do not prove that every designation, product form, condition or spring application is interchangeable.
Spring Performance Cannot Be Promised from a Grade Name
Fatigue life and spring performance depend on the finished component design, material cleanliness and condition, surface quality, decarburization, forming route, hardening and tempering, residual stress, shot peening, service loading and inspection. A steel-grade designation or generic material table cannot validate the finished spring.
The buyer should define who owns the final heat-treatment procedure, property validation, fatigue testing and component approval. Junxiong’s quotation should state whether the scope is upstream bar, cut blank or another agreed product stage.
Buyer Checklist Before Quotation
- Exact grade designation, governing standard and standard edition.
- Shape, finished dimensions and machining or forming allowance.
- Dimensional tolerance, straightness, twist, flatness, corner and length limits.
- Incoming delivery condition and downstream hardening and tempering route.
- Surface condition, defect and decarburization limits with inspection method.
- Required hardness, mechanical properties, fatigue validation and test-piece location.
- MTC, heat traceability and third-party inspection requirements.
- Quantity per size, repeat demand, destination, schedule and packing.
FAQ for 6150, 51CrV4 and SUP10 Spring Steel Buyers
Can Junxiong supply 6150 or 51CrV4 cold-finished bar?
Junxiong can review and supply the requirement after confirming the governing standard, shape, size, tolerance, incoming condition, downstream process, property requirements, quantity and destination.
Is 51CrV4 exactly the same as SAE 6150?
No automatic substitution is assumed. They are commonly compared, while the ordered standard, chemistry, product form, condition, heat treatment and acceptance criteria control supply.
Is SUP10 automatically equivalent to SAE 6150 or 51CrV4?
No. SUP10 follows the buyer’s specified JIS route. Any proposed alternative requires a documented standards comparison covering chemistry, product form, condition, heat-treatment response and acceptance criteria, plus written buyer approval.
Can the page promise spring fatigue life?
No. Fatigue life depends on design, material condition, surface quality, forming, heat treatment, residual stress, service loading and inspection. It cannot be guaranteed from a grade name alone.
Can round, flat, square, hexagonal or custom sections be reviewed?
Yes, subject to the exact standard, dimensions, incoming condition, tooling, surface/decarburization controls, downstream process and quantity.
What proves the delivered grade and condition?
The approved purchase specification, heat identity, MTC and agreed chemistry, condition, dimensional and inspection records establish batch conformity. Representative photographs do not.
Related Cold Drawn Steel Pages
- Cold drawn steel bars and RFQ guide
- Cold drawn round steel bar
- Cold drawn flat steel bar
- Cold drawn square steel bar
- Cold drawn hexagonal steel bar
- Custom cold drawn steel profiles
- Factory and quality verification
Send the complete 6150, 51CrV4 or SUP10 specification for factory review.