What is 30H3MF steel?
30H3MF is a chromium, molybdenum and vanadium nitriding steel designated under the Polish PN system, with the same composition limits as EN 10250-3 grade 30CrMoV9, material number 1.7707. It carries nominally 0.30 % carbon, 2.5 % chromium, 0.20 % molybdenum and 0.15 % vanadium, and is supplied quenched and tempered with a minimum tensile strength of 800 to 900 MPa depending on section.
What separates this grade from a plain Cr-Mo steel is what happens at the surface. Chromium, molybdenum and vanadium all form stable nitrides, so after nitriding the outer layer reaches around 800 HV while the core keeps the toughness given by quenching and tempering. That combination is why it is specified for piston pins, extruder barrels, valve parts and gears rather than for general structural work.
Jiangyin Jiangnan Metal Co., Ltd. produces 30H3MF as open-die forgings and seamless rolled rings to customer drawings, from EAF + LF + VD melted material.
- Grade
- 30H3MF / 30CrMoV9
- Material number
- 1.7707
- Forging standard
- EN 10250-3:2000
- Nitriding standard
- EN 10085 (31CrMoV9, 1.8519)
- Melting route
- EAF + LF + VD
- Delivery condition
- +A or +QT, nitrided on request
- Tensile strength (+QT)
- 800 to 900 MPa minimum
- Annealed hardness
- 248 HB max
- Nitrided surface
- approx. 800 HV1, 64 HRC
- Weldability
- Not recommended
- Ultrasonic testing
- EN 10228-3, SEP 1921, ASTM A388
- Certificate
- EN 10204 3.1 or 3.2
Chemical composition of 30H3MF
The table below gives the cast analysis limits of EN 10250-3:2000 for grade 30CrMoV9 (1.7707), which is the specification 30H3MF is normally traded against.
| Element | Symbol | EN 10250-3:2000 | Role in the alloy |
|---|---|---|---|
| Carbon | C | 0.26–0.34 | Sets core strength after tempering |
| Silicon | Si | 0.40 max | Deoxidiser |
| Manganese | Mn | 0.40–0.70 | Hardenability, sulphur control |
| Phosphorus | P | 0.035 max | Residual, kept low for toughness |
| Sulphur | S | 0.035 max | Residual, kept low for transverse ductility |
| Chromium | Cr | 2.30–2.70 | Hardenability, temper resistance, main nitride former |
| Molybdenum | Mo | 0.15–0.25 | Suppresses temper embrittlement, nitride former |
| Vanadium | V | 0.10–0.20 | Grain refinement, fine stable nitrides |
| Nickel | Ni | 0.60 max | Residual |
| Iron | Fe | Balance |
Two things catch buyers out on this grade. First, EN 31CrMoV9 (1.8519) in the nitriding steel standard EN 10085 runs the same chromium, molybdenum and vanadium but tightens phosphorus to 0.025 % maximum and does not list nickel. Second, the Polish system also holds 30H2MF and 33H3MF, which are near neighbours with different limits, 33H3MF carrying roughly 0.35 to 0.45 % molybdenum. State the standard and its edition on the purchase order and Jiangyin Jiangnan Metal will melt and certify to it.
Mechanical properties of 30H3MF after quenching and tempering
Properties fall as section size grows, because the quench cools a thick section more slowly at its core. EN 10250-3 therefore specifies minimum values against a ruling section.
| Ruling section | Yield Re min | Tensile Rm min | Elongation A min, longitudinal | Elongation A min, transverse |
|---|---|---|---|---|
| up to 160 mm (6.30 in) | 700 MPa (102 ksi) | 900 MPa (131 ksi) | 12 % | 8–10 % |
| 160–330 mm (6.30–13.0 in) | 590 MPa (86 ksi) | 800 MPa (116 ksi) | 14 % | 8–10 % |
In the soft annealed condition (+A) the hardness is 248 HB maximum. Where an order is placed against EN 10085 grade 31CrMoV9 instead, the quenched and tempered band is quoted as 850 to 1300 MPa tensile with 650 MPa minimum yield, 9 % minimum elongation and 25 J minimum Charpy V-notch energy. For forgings heavier than the 330 mm ruling section, properties are agreed at enquiry and verified on a prolongation or sacrificial test block.
| Property | Value |
|---|---|
| Density | approx. 7.8 g/cm³ (0.282 lb/in³) |
| Modulus of elasticity, 20 °C | 210 GPa (30.5 × 106 psi) |
| Poisson's ratio | 0.30 |
| Coefficient of thermal expansion, 20–100 °C | 11.1 × 10−6/K |
| Coefficient of thermal expansion, 20–300 °C | 12.9 × 10−6/K |
| Coefficient of thermal expansion, 20–500 °C | 13.9 × 10−6/K |
| Surface hardness after nitriding | approx. 800 HV1 (64 HRC) |
| Hardness, soft annealed (+A) | 248 HB max |
30H3MF equivalent grades
30H3MF is cross-referenced internationally as follows. Cross-references are guides, not substitutions: confirm the governing standard on the order before a grade is swapped.
| Country or body | Standard | Designation | Match |
|---|---|---|---|
| Poland | PN | 30H3MF | Subject designation |
| Europe | EN 10250-3 | 30CrMoV9, 1.7707 | Same composition limits |
| Europe | EN 10085 | 31CrMoV9, 1.8519 | Nitriding edition, close substitute |
| Germany | DIN 17200 (withdrawn) | 30 CrMoV 9, 1.7707 | Same grade |
| Russia and CIS | GOST | 30Х3МФ (30Kh3MF, 30Ch3MF) | Near equivalent |
| Czech Republic | ČSN | 15241 (30CrMoV9), 15330 (31CrMoV9) | Near equivalent |
| United States | SAE / AISI | No direct equivalent | Not a substitute |
There is no clean American counterpart. AISI 4140 and 4340 are sometimes offered against 30H3MF enquiries because the strength bands overlap, but neither is a nitriding steel of this type: 4140 carries about 1 % chromium against 2.5 %, and neither carries vanadium. A part designed to be nitrided will not reach the same case hardness in those grades. The GOST grade 30Kh3MF is the closer trade substitute, running slightly higher molybdenum and lower vanadium.
Heat treatment and nitriding of 30H3MF forgings
| Operation | Temperature | Cooling |
|---|---|---|
| Hot forging | 1050–1150 °C (1920–2100 °F) | Reheat if the piece falls below 850 °C. Cool slowly in the furnace or in sand. |
| Soft annealing | 650–720 °C (1200–1330 °F) | Furnace cool, to 248 HB max |
| Hardening | 870–930 °C (1600–1710 °F) | Oil or polymer quench; water only on light sections |
| Tempering | 580–700 °C (1075–1290 °F) | Still air, tempering temperature chosen to hit the specified strength band |
| Nitriding | 500–580 °C (930–1075 °F) | Gas or plasma, after finish machining; case depth to drawing |
| Stress relieving | approx. 50 °C below the tempering temperature | Furnace cool |
This grade cracks readily if a heavy forging is cooled too quickly from forging heat, so slow cooling and an anti-flake treatment are applied before any machining. Note also that nitriding is carried out below the tempering temperature. Tempering must therefore be set high enough that the nitriding cycle cannot soften the core, which is why the tempering range and the required core strength are agreed together at order stage.
How Jiangyin Jiangnan Metal makes 30H3MF forgings
- MeltingElectric arc furnace, ladle refining and vacuum degassing (EAF + LF + VD) to control gas content and inclusions. Electroslag remelting (ESR) is available where the specification calls for it.
- Open-die forgingIngots and billets are upset and drawn on hydraulic presses to break down the cast structure. A forging ratio of at least 3:1 is applied unless the drawing says otherwise.
- Controlled coolingForgings are cooled in the furnace or in sand and given an anti-flake treatment, because this grade is crack sensitive from forging heat.
- Heat treatmentAnnealing, or quenching and tempering, in furnaces with recorded charts, followed by the property testing agreed on the order.
- MachiningRough or finish machining to the drawing, including bores, faces, grooves and threads. Parts to be nitrided are finish machined first.
- Inspection and releaseChemical analysis, mechanical testing, ultrasonic and magnetic particle inspection, dimensional check, then release with an EN 10204 3.1 or 3.2 certificate.
Product forms supplied in 30H3MF
- Forged round bars, square bars, flat bars and hexagonal bars
- Forged sleeves, bushings and hollow bars
- Forged cylinders, barrels, casings and shells
- Seamless rolled rings and forged rings
- Forged shafts, gear shafts, pinion shafts and spindles
- Forged discs, blocks and gear blanks
- Forged crankshafts and camshaft blanks
- Forged valve bodies, valve seats and valve stems
| Form | Outside diameter or width | Length or height | Single piece weight |
|---|---|---|---|
| Rolled rings | 200–4000 mm | up to 1000 mm | up to 20 t |
| Shafts and round bars | 80–1200 mm | up to 8000 mm | up to 20 t |
| Discs and blanks | up to 2500 mm | up to 600 mm | up to 20 t |
| Blocks and slabs | up to 1500 mm | up to 4000 mm | up to 20 t |
Sizes outside this range are quoted on request. Send the drawing and Jiangyin Jiangnan Metal will confirm feasibility, ingot size and the machining allowance needed.
Where 30H3MF forgings are used
30H3MF is specified when a part has to survive rubbing contact or high surface stress without giving up core toughness, and where the working temperature is too high for a case-hardened steel to hold its properties.
| Industry | Typical 30H3MF forgings |
|---|---|
| Engines and powertrain | Piston pins, gudgeon pins, camshafts, connecting rod parts, cylinders for combustion engines |
| Power transmission | Gears, ring gears, pinion shafts, gearbox spindles, gear blanks |
| Valves and fittings | Valve bodies, gate valve parts, valve stems, superheated steam valves and fittings |
| Plastics and extrusion | Extruder barrels and liners, screw blanks, wear sleeves |
| Hydraulics | Cylinder tubes, piston rods, rams, plungers |
| Machine tools | Spindles, straightening rolls, guide bars, measuring and gauge tooling |
| Power generation | Turbine fasteners, studs and high temperature bolting |
| Pumps and compressors | Shafts, plunger pump parts, wear sleeves and bushings |
Testing and certification
Non-destructive testing
- Ultrasonic testing to EN 10228-3, SEP 1921 class C/c to E/e, or ASTM A388
- Magnetic particle inspection to EN 10228-1 or ASTM E709
- Liquid penetrant inspection to ASTM E165 on request
Destructive and chemical testing
- Tensile test to EN ISO 6892-1 or ASTM A370
- Charpy V-notch impact test, including sub-zero temperatures
- Brinell hardness survey to EN ISO 6506
- Product analysis by optical emission spectrometry
- Grain size, macro-etch and inclusion rating on request
Where parts are supplied nitrided, the case is verified as well as the core: surface hardness by Vickers to EN ISO 6507, nitriding hardness depth on a sectioned coupon to EN ISO 18203, and a metallographic check of the compound layer. Every 30H3MF forging ships with a mill test certificate to EN 10204 3.1. Where the customer or the notified body requires independent verification, Jiangyin Jiangnan Metal arranges third-party inspection and an EN 10204 3.2 certificate through SGS, BV, TUV or the customer's own inspector.
Frequently asked questions about 30H3MF
Is 30H3MF the same as 30CrMoV9 and 1.7707?
For practical purposes yes. 30H3MF is the Polish PN designation and 30CrMoV9, material number 1.7707, is the EN 10250-3 designation, and the two carry the same composition limits. Purchase orders, drawings and mill certificates use both, and Jiangyin Jiangnan Metal certifies against whichever designation the order specifies.
What is the chemical composition of 30H3MF?
Per EN 10250-3:2000 for grade 30CrMoV9, the limits are 0.26–0.34 % carbon, 0.40 % silicon maximum, 0.40–0.70 % manganese, 2.30–2.70 % chromium, 0.15–0.25 % molybdenum and 0.10–0.20 % vanadium, with nickel 0.60 % maximum, phosphorus 0.035 % maximum and sulphur 0.035 % maximum. EN 31CrMoV9 (1.8519) runs the same alloy elements but tightens phosphorus to 0.025 % maximum.
What are the mechanical properties of 30H3MF after quenching and tempering?
In the quenched and tempered condition, 30H3MF gives 900 MPa minimum tensile strength with 700 MPa minimum yield for sections up to 160 mm, and 800 MPa minimum tensile with 590 MPa minimum yield for sections from 160 to 330 mm. Minimum longitudinal elongation is 12 % and 14 % respectively, with 8 to 10 % transverse.
What heat treatment does 30H3MF require?
Hot forging is carried out between 1050 and 1150 °C followed by slow cooling in the furnace or in sand. Soft annealing is 650–720 °C with furnace cooling to 248 HB maximum, hardening 870–930 °C in oil or polymer, and tempering 580–700 °C in still air.
What surface hardness does 30H3MF reach after nitriding?
Around 800 HV1, roughly 64 HRC. The chromium, molybdenum and vanadium in the alloy form fine, stable nitrides that build the case. Nitriding runs at 500 to 580 °C on a finish-machined part, so the core keeps whatever strength the earlier tempering gave it, provided the tempering temperature was set above the nitriding temperature.
What is the difference between 30H3MF and 31CrMoV9 (1.8519)?
The alloy content is effectively the same. 30CrMoV9 (1.7707) sits in EN 10250-3, the open-die forging standard, while 31CrMoV9 (1.8519) sits in EN 10085, the nitriding steel standard, with phosphorus tightened to 0.025 % maximum and no nickel limit listed. Where a drawing calls for a nitrided part, buyers often accept either.
Can 30H3MF be welded?
It is not regarded as suitable for welding. The carbon and the 2.5 % chromium make the heat-affected zone hardenable and crack sensitive, and welding a finished quenched and tempered or nitrided part will locally destroy its properties. Design the joint out of the part wherever possible. If a weld cannot be avoided, agree the procedure, preheat and post-weld heat treatment with Jiangyin Jiangnan Metal before the order is placed.
What is the forging temperature for 30H3MF?
Between 1050 and 1150 °C, reheating if the piece falls below 850 °C. Cooling afterwards matters as much as the forging temperature: this grade cracks readily if cooled too fast, so forgings are cooled in the furnace or in sand rather than in still air.
Why is 30H3MF used for extruder barrels and cylinder liners?
An extruder barrel is abraded from the inside for years at temperature. A nitrided 30H3MF bore holds around 800 HV against that abrasion, while the wall behind it stays tough enough to carry pressure and thermal stress. A through-hardened steel at that surface hardness would be too brittle for the wall, and a case-hardened steel would temper back at working temperature.
What is the minimum order quantity for 30H3MF forgings?
Jiangyin Jiangnan Metal accepts single-piece orders for open-die forgings, including prototypes and spare parts. Batch pricing improves once several pieces share one ingot or one heat-treatment charge, so send the full requirement with the enquiry.
Which documents ship with 30H3MF forgings?
A mill test certificate to EN 10204 3.1 as standard, covering heat number, chemical analysis, heat treatment record and mechanical test results, with the ultrasonic and magnetic particle reports attached. Nitrided parts add surface hardness and case depth results. EN 10204 3.2 certification with third-party witness is available on request.
How do I request a quotation for 30H3MF forgings?
Email the drawing or the finished dimensions to sales@steelforgepieces.com, or call +86 189 2135 9659. Include the delivery condition, the testing standard, the certificate type and the quantity, and a price follows with the confirmed lead time.
Sources and citation
Data on this page is compiled from the following published standards and from the production records of Jiangyin Jiangnan Metal Co., Ltd.
- EN 10250-3:2000, Open die steel forgings for general engineering purposes. Alloy special steels.
- EN 10085:2001, Nitriding steels. Technical delivery conditions.
- DIN 17200 (withdrawn), Quenched and tempered steels.
- EN 10228-1 and EN 10228-3, Non-destructive testing of steel forgings.
- EN ISO 18203, Determination of the thickness of surface-hardened layers.
- EN 10204:2004, Metallic products, types of inspection documents.
- EN 10027-1, Designation systems for steels.
Cite this page: Jiangyin Jiangnan Metal Co., Ltd. (2026). 30H3MF Forgings, Grade Data Sheet (30CrMoV9 / 1.7707). Retrieved from https://www.steelforgepieces.com/Alloy-Steel/30H3MF.html
Reviewed by the technical sales team of Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu, China. Last updated .
Send a drawing, get a price
Jiangyin Jiangnan Metal Co., Ltd. forges 30H3MF to your drawing, heat treats it, machines it, nitrides it where required and certifies it. Quotations are normally returned within one working day.
Email the drawing Call +86 189 2135 9659
Include these six things and the quotation comes back complete:
- Drawing or finished dimensions, with machining allowance if known
- Quantity and whether this is a prototype or a repeat order
- Delivery condition: annealed, quenched and tempered, or nitrided
- Required core properties or hardness range, and case depth if nitrided
- Testing standard and acceptance class, for example EN 10228-3 class 3
- Certificate type: EN 10204 3.1 or 3.2
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China, supplying forged rings, shafts, flanges, discs, bars and made-to-drawing forgings in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys. The factory works from EAF + LF + VD melted material, heat treats in house, and certifies to EN 10204 3.1 or 3.2. Jiangyin sits in the lower Yangtze forging cluster, with the ports of Shanghai and Zhangjiagang within a day’s road haulage.
Jiangyin Jiangnan Metal Co., Ltd.No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone +86 189 2135 9659
Email sales@steelforgepieces.com
Web www.steelforgepieces.com