1. 52CrMoV4 at a glance
52CrMoV4 is a medium-carbon alloy steel containing approximately 0.52 % carbon, 1.0 % chromium, 0.2 % molybdenum and 0.15 % vanadium. Chromium and vanadium form carbides that retain hardness during tempering. Molybdenum increases hardenability and reduces temper embrittlement in the 350 to 550 °C range. After quenching and tempering the steel reaches a tensile strength of 1370 to 1670 N/mm² with a 0.2 % proof stress of 1180 N/mm² minimum.
The grade is normally selected in place of 51CrV4 (1.8159) when the section is too heavy for a chromium-vanadium steel to harden to the core. The difference between the two grades is the molybdenum content: 0.15 to 0.30 % in 52CrMoV4 and none in 51CrV4.
| Grade designation | 52CrMoV4 |
|---|---|
| EN material number | 1.7701 |
| Standard | EN 10089:2002, hot-rolled steels for quenched and tempered springs. Previously DIN 17221. |
| Classification | Alloy special steel, Cr-Mo-V spring steel |
| Other designations | 51CrMoV4, AFNOR 51CDV4, former brand name F 4 K |
| Density | 7.78 g/cm³ |
| Modulus of elasticity | 210 kN/mm² (210 GPa) at ambient temperature |
| 0.2 % proof stress, quenched and tempered | 1180 N/mm² minimum |
| Tensile strength, quenched and tempered | 1370 to 1670 N/mm² |
| Hardness, soft annealed | 255 HB maximum |
| Weldability | Not recommended. Carbon and alloy content make the steel crack sensitive. |
| Forged forms supplied | Round and flat bars, forged rings, seamless rolled rings, discs, blocks, shafts, hollow bars, sleeves, rolls |
| Supplier | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |
2. Chemical composition
The table gives the composition range required by EN 10089:2002 together with the typical ladle analysis of the billet used by Jiangyin Jiangnan Metal. Each heat is supplied with a mill certificate to EN 10204 3.1.
| Element | C | Si | Mn | P | S | Cr | Mo | V |
|---|---|---|---|---|---|---|---|---|
| EN 10089 range | 0.48-0.56 | max 0.40 | 0.70-1.10 | max 0.025 | max 0.025 | 0.90-1.20 | 0.15-0.30 | 0.10-0.20 |
| Typical analysis | 0.54 | 0.28 | 0.90 | — | — | 1.05 | 0.20 | 0.20 |
Residual limit: Cu + 10 Sn below 0.60 %. Elements not listed are not added deliberately.
Function of the alloying elements
| Element | Range, % | Function |
|---|---|---|
| Carbon | 0.48-0.56 | Sets the attainable as-quenched hardness and the elastic limit of the finished part |
| Silicon | max 0.40 | Deoxidiser, contributes to strength in solid solution |
| Manganese | 0.70-1.10 | Increases hardenability and binds sulphur |
| Chromium | 0.90-1.20 | Increases hardenability and forms carbides that resist softening on tempering |
| Molybdenum | 0.15-0.30 | Increases hardenability in heavy sections and reduces temper embrittlement between 350 and 550 °C |
| Vanadium | 0.10-0.20 | Restricts austenite grain growth during forging and hardening, improves fatigue strength |
3. Equivalent and comparable grades
52CrMoV4 has no exact one-to-one equivalent in the American standards. The table states what differs in each case.
| Standard or region | Designation | Relationship to 52CrMoV4 |
|---|---|---|
| EN, Europe | 52CrMoV4, 1.7701 | The grade itself, to EN 10089:2002 |
| DIN, Germany, superseded | 52CrMoV4 or 51CrMoV4, DIN 17221 | Same steel under the withdrawn standard. Some mills still label it 51CrMoV4. |
| AFNOR, France | 51CDV4 | Accepted equivalent |
| AISI / SAE, USA | 4150, G41500 | Near match. Carbon, chromium and molybdenum are comparable but 4150 contains no specified vanadium, so grain refinement and tempering resistance differ. Substitution requires written customer approval. |
| EN, related grade | 51CrV4, 1.8159, approx. AISI 6150 | Same Cr-V base without molybdenum. Lower hardenability, suited to thinner sections. |
| EN, related grades | 50CrV4, 58CrV4, 60CrMo3-3 | Other EN 10089 spring steels, selected by section thickness and required strength |
Cross-references are given for guidance. Where a drawing calls out 52CrMoV4 to EN 10089, Jiangyin Jiangnan Metal supplies and certifies that grade.
4. Mechanical properties
The values below apply in the quenched and tempered condition at ambient temperature, measured on the reference sample defined in the standard.
| Property | Value | Unit |
|---|---|---|
| 0.2 % proof stress, Rp0.2 | 1180 | N/mm² (MPa), minimum |
| Tensile strength, Rm | 1370-1670 | N/mm² (MPa) |
| Elongation, A | 6 | %, minimum |
| Hardness, soft annealed | max 255 | HB |
| Hardness, quenched and tempered, indicative | 415-490 | HB, approx. 44-49 HRC |
Quenched and tempered hardness is converted from tensile strength to EN ISO 18265 and is indicative. Where hardness is a contract requirement it is measured directly and reported on the certificate.
Effect of section size
Properties in a forging vary with section size. Heavier sections cool more slowly during quenching, so core strength falls towards the lower end of the band. For forgings above approximately 150 mm ruling section, state the required properties and the depth at which they are to be verified rather than quoting the grade alone. Jiangyin Jiangnan Metal confirms achievable values against the drawing before quotation.
5. Physical properties
| Property | Value | Unit |
|---|---|---|
| Density | 7.78 | g/cm³ |
| Modulus of elasticity, longitudinal | 210 | 10³ × N/mm² (GPa) |
| Modulus of rigidity, shear, typical | 80 | GPa |
| Magnetic response | Ferromagnetic | in all conditions |
The shear modulus is the accepted typical figure for this steel class and is used in torsion bar and coil spring rate calculations.
6. Heat treatment
Jiangyin Jiangnan Metal supplies 52CrMoV4 in the as-forged, normalised, annealed or quenched and tempered condition. The cycles below are standard practice for the grade.
| Operation | Temperature | Cooling | Result |
|---|---|---|---|
| Hot forming and forging | 1050-850 °C | Slow, in furnace or ash | Forging finished above 850 °C |
| Soft annealing | 640-680 °C | Slow, in furnace | 255 HB maximum, best machinability |
| Normalising | 850-880 °C | Air | Uniform fine grain, refines the forged structure |
| Hardening | 830-860 °C | Oil quench | Full martensite in suitable sections |
| Tempering | 350-550 °C | Air | Sets final strength. 400 to 500 °C is usual for springs. |
Tempering notes
Parts should be transferred to the tempering furnace directly after quenching, while still hand warm. A quenched 0.5 % carbon alloy steel held at room temperature can crack from residual stress. The tempering temperature is selected from the required tensile strength band in section 4. A higher tempering temperature gives lower strength and higher ductility.
7. Forging practice
52CrMoV4 hardens in still air. Forgings cooled without protection can develop quench cracks, and heavy sections are sensitive to hydrogen flaking. The following practice is applied at Jiangyin Jiangnan Metal for this grade.
- Heat the billet to 1050 °C and soak until the temperature is equalised through the section. Rapid heating of a thick billet places the surface in tension against a cold core.
- Forge between 1050 and 850 °C. Reheat rather than continue forging below 850 °C.
- Work to a forging ratio of at least 3:1, or higher where the customer specifies it, to break down the cast structure and close centreline porosity.
- Transfer the forging from the press to a slow-cool box or furnace, then soft anneal or normalise within the same shift.
- Carry out ultrasonic testing after rough machining rather than on the black forging.
Welding is not recommended for this grade. Where a welded joint cannot be avoided, weld in the annealed condition with preheat above 300 °C and apply a full post-weld heat treatment. Fatigue strength at the joint will be lower than in the parent material.
8. Forged product forms in 52CrMoV4
Jiangyin Jiangnan Metal is an open-die forging factory, so 52CrMoV4 is produced to drawing rather than held as catalogue stock. The following shapes are produced routinely in this grade.
| Product form | Typical size range | Notes |
|---|---|---|
| Forged round bars and shafts | Diameter 80 to 1200 mm, length up to 12000 mm | Stepped shafts, spindles, torsion bar blanks |
| Forged square, flat and hexagonal bars | Thickness 40 to 600 mm, width up to 1200 mm | Leaf spring and knife blanks |
| Forged rings | Outside diameter 200 to 3000 mm | Trepanned from solid, or upset and punched |
| Seamless rolled rings | Outside diameter 300 to 3500 mm, height up to 800 mm | Grain flow follows the circumference |
| Forged discs, blocks and plates | Diameter or width up to 2500 mm | Gear and coupling blanks, die blocks |
| Hollow bars, sleeves, bushings, cylinders | Outside diameter up to 2000 mm, bore from 80 mm | Bored or trepanned to reduce machining allowance |
| Rolls and roll blanks | Barrel diameter up to 1200 mm | Work rolls, back-up rolls, levelling and straightening rolls |
Size ranges are typical rather than absolute limits. Send the drawing with the enquiry and feasibility and weight will be confirmed before quotation.
9. Typical applications
52CrMoV4 is specified for parts that store elastic energy, carry high cyclic loads, and are too thick in section for a plain chromium-vanadium spring steel.
- Automotive suspension: leaf springs, parabolic springs, helical vehicle springs, anti-roll and stabiliser bars, torsion bars.
- Highly stressed springs: torsion springs, threaded springs, coil springs, disc springs.
- Machine and engine components: shafts, spindles, couplings and drive parts working at high stress.
- Wood and pulp processing: bark-removing and debarking knives.
- Rolling mill and processing lines: levelling and straightening rolls, work and intermediate rolls for levellers, scale-breaker rolls for thin gauge material in pickling line cassettes, and rolls for cut-to-length and tension levellers in galvanising and electrolytic tinning lines.
10. Ordering, testing and documentation
Every 52CrMoV4 forging supplied by Jiangyin Jiangnan Metal ships with a mill certificate to EN 10204 3.1, covering heat number, chemical analysis, heat treatment record and mechanical test results. A 3.2 certificate with third-party witness by SGS, BV, TUV or the customer's own inspector is available on request.
Testing available
- Chemical analysis by spectrometer, per heat
- Tensile strength, yield strength, elongation and reduction of area
- Charpy V-notch impact testing at ambient or sub-zero temperature
- Brinell and Rockwell hardness, including through-section surveys
- Ultrasonic testing to EN 10228-3, ASTM A388 or SEP 1921, after rough machining
- Magnetic particle and dye penetrant inspection
- Grain size, macro-etch and metallographic examination
Information required for a quotation
- Drawing or finished dimensions, and whether the price is to include rough machining
- Quantity, and whether the order repeats
- Delivery condition: as forged, normalised, annealed, or quenched and tempered to a stated strength or hardness
- Applicable standard and certificate level, EN 10204 3.1 or 3.2
- Non-destructive testing requirement and acceptance class
- Destination port and required delivery date
Send the enquiry
Email sales@steelforgepieces.com or call +86 189 2135 9659. Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China.
11. Frequently asked questions about 52CrMoV4
What is 52CrMoV4 steel?
52CrMoV4 is a chromium-molybdenum-vanadium alloy spring steel with EN material number 1.7701, specified in EN 10089:2002 for hot-rolled steels that are quenched and tempered for springs. It contains approximately 0.52 % carbon, 1.0 % chromium, 0.2 % molybdenum and 0.15 % vanadium, and reaches 1370 to 1670 N/mm² tensile strength after heat treatment.
What is the material number for 52CrMoV4?
The EN material number for 52CrMoV4 is 1.7701. The same steel is also designated 51CrMoV4 by some mills and 51CDV4 under the French AFNOR system.
Is 52CrMoV4 the same as AISI 4150?
No. AISI/SAE 4150 is often quoted as the closest American grade because carbon, chromium and molybdenum levels are comparable, but 4150 contains no specified vanadium. Without vanadium the steel has coarser grain and lower tempering resistance. 4150 should be treated as a near match rather than an equivalent, and substitution requires written approval.
What is the difference between 52CrMoV4 and 51CrV4?
52CrMoV4 (1.7701) contains 0.15 to 0.30 % molybdenum. 51CrV4 (1.8159) contains none. Molybdenum increases hardenability, so 52CrMoV4 hardens through heavier sections and resists temper embrittlement between 350 and 550 °C. For thin springs 51CrV4 is usually adequate. For thick bars, torsion bars and forgings, 52CrMoV4 is the correct choice.
How is 52CrMoV4 heat treated?
52CrMoV4 is hardened from 830 to 860 °C with an oil quench, then tempered at 350 to 550 °C and cooled in air. Soft annealing is carried out at 640 to 680 °C with slow furnace cooling, giving a maximum hardness of 255 HB. Normalising is carried out at 850 to 880 °C with air cooling. Parts should be tempered immediately after quenching to avoid cracking.
At what temperature is 52CrMoV4 forged?
52CrMoV4 is forged between 1050 and 850 °C. Forging must be finished above 850 °C, and the forging must then be cooled slowly and annealed or normalised without delay, because the steel hardens in still air and is prone to cracking and hydrogen flaking in heavy sections.
Can 52CrMoV4 be welded?
Welding 52CrMoV4 is not recommended. At approximately 0.52 % carbon with chromium and molybdenum it forms hard martensite in the heat-affected zone and cracks readily. Where welding cannot be avoided, weld in the annealed condition with preheat above 300 °C followed by a full post-weld heat treatment, and expect reduced fatigue strength at the joint.
What is 52CrMoV4 used for?
52CrMoV4 is used for heavily stressed automotive springs including leaf springs, helical vehicle springs, stabiliser bars and torsion bars, as well as torsion and disc springs, highly loaded machine and engine components, bark-removing knives, and levelling, straightening and scale-breaker rolls in steel processing lines.
Where can I buy 52CrMoV4 forgings?
Jiangyin Jiangnan Metal Co., Ltd. manufactures 52CrMoV4 (1.7701) open-die forgings to customer drawings at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China. Available forms include forged bars and shafts, forged and seamless rolled rings, discs, blocks, hollow bars, sleeves and rolls, supplied with EN 10204 3.1 certification. Enquiries: sales@steelforgepieces.com, +86 189 2135 9659.
What is the minimum order quantity for 52CrMoV4 forgings?
52CrMoV4 forgings are made to order, so there is no fixed piece minimum. Single prototype forgings and one-off replacement parts are quoted alongside production batches. Cost per piece falls once an order covers a full billet, so requesting pricing at two quantities is useful.
12. Document information
This datasheet is maintained by the technical department of Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu, China. It is based on EN 10089:2002 together with the company's own production and testing records for this grade.
| Cite as | Jiangyin Jiangnan Metal Co., Ltd. 52CrMoV4 (1.7701) Open-Die Forgings: Composition, Properties, Heat Treatment and Forging Practice. steelforgepieces.com. |
|---|---|
| Page address | www.steelforgepieces.com/Alloy-Steel/52CrMoV4.html |
| Primary standard | EN 10089:2002, hot-rolled steels for quenched and tempered springs |
| Last reviewed | |
| Technical contact | sales@steelforgepieces.com, +86 189 2135 9659 |
Data is given for engineering guidance. Values depend on section size and processing route. Confirm requirements against the mill certificate supplied with the order.