# 28Mn6 (1.1170) Steel Forgings

**Manufacturer:** Jiangyin Jiangnan Metal Co., Ltd.
**Address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
**Telephone:** +86 189 2135 9659
**Email:** sales@steelforgepieces.com
**Page:** https://www.steelforgepieces.com/Alloy-Steel/28Mn6.html
**Last reviewed:** 10 September 2026

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## Summary

28Mn6 (material number 1.1170) is a manganese steel for quenching and tempering to EN 10083-2:2006. It contains 0.25–0.32 % carbon and 1.30–1.65 % manganese. The manganese content raises hardenability and strength above a plain carbon steel of the same carbon level while keeping good weldability and machinability. It is used for shafts, gears, couplings, pins and pressure-retaining parts under moderate load, including service below room temperature where notch toughness is required.

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. We manufacture 28Mn6 / 1.1170 forgings to customer drawings: forged round, square, flat and hexagonal bars; hollow bars, sleeves, bushings and cylinders; seamless rolled rings and forged rings; discs, blocks and plates; gear shafts, pinion shafts and spindles. Piece weight ranges from about 50 kg to 30 tonnes. Parts are supplied annealed, normalised or quenched and tempered with EN 10204 3.1 or 3.2 material certificates.

| Item | Value |
|---|---|
| Grade designation | 28Mn6 (EN name), 1.1170 (EN number) |
| Standard | EN 10083-2:2006, Steels for quenching and tempering, Part 2: Technical delivery conditions for non-alloy steels |
| Steel family | Manganese steel for quenching and tempering |
| Closest US grade | SAE/AISI 1330 (UNS G13300), nearest equivalent |
| Delivery conditions | +A soft annealed, +S treated for shearability, +N normalised, +QT quenched and tempered |
| Weldability | Weldable with preheat; carbon equivalent typically CEV 0.55–0.65 |
| Typical uses | Shafts, gears, couplings, flanges, pins, low-temperature pressure vessel parts |

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## Chemical composition

Ladle analysis limits per EN 10083-2:2006, weight percent.

| Element | C | Si | Mn | P | S | Cr | Mo | Ni |
|---|---|---|---|---|---|---|---|---|
| Limits (%) | 0.25–0.32 | max 0.40 | 1.30–1.65 | max 0.030 | max 0.035 | max 0.40 | max 0.10 | max 0.40 |

Residual elements are further restricted by Cr + Mo + Ni = max 0.63 %. Sulphur may be raised to 0.020–0.040 % where free-cutting behaviour is specified.

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## Mechanical properties

### Normalised condition (+N), minimum values

| Nominal thickness / diameter (mm) | to 16 | 16–100 | 100–250 | 250–500 | 500–1000 |
|---|---|---|---|---|---|
| Rm, tensile strength, MPa min. | 630 | 600 | 570 | 540 | 540 |
| ReH / Rp0.2, yield strength, MPa min. | 345 | 310 | 290 | 270 | 260 |
| A, elongation, Lo = 5.65√So, % min. | 17 | 18 | 18 | – | – |

### Quenched and tempered condition (+QT), typical values

| Diameter (mm) | Rp0.2 MPa min. | Rm MPa | A % min. | Z % min. | KV (ISO-V) J min. |
|---|---|---|---|---|---|
| up to 16 | 590 | 800–950 | 13 | 40 | 35 |
| 16–40 | 490 | 700–850 | 15 | 45 | 40 |
| 40–100 | 440 | 650–800 | 16 | 50 | 40 |
| 100–160 | 390 | 590–740 | 18 | – | – |
| 160–250 | 390 | 590–740 | 18 | – | – |
| 250–500 | 340 | 540–690 | 19 | – | – |

Impact energy quoted at +20 °C. Above 250 mm section, properties depend on the forging reduction ratio and the quench medium and are agreed case by case before order confirmation.

Above about 250 mm section, manganese alone will not through-harden the forging. Either the lower core properties shown above are accepted, or the part is better made in 42CrMo4.

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## Hardness and hardenability

| Delivery condition | Brinell hardness, HBW max. |
|---|---|
| +S, treated to improve shearability | 255 |
| +A, soft annealed | 223 |

### Jominy end-quench hardenability (+H), HRC, quench temperature 850 °C

| Distance, mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 40 | 50 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HRC max. | 54 | 53 | 51 | 48 | 44 | 41 | 38 | 35 | 31 | 29 | 27 | 25 | 24 |
| HRC min. | 45 | 42 | 37 | 27 | 21 | – | – | – | – | – | – | – | – |

Restricted scatter bands +HH (upper half) and +HL (lower half) can be ordered where the heat-treatment window is tight.

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## Physical properties

| Property | Value | Unit |
|---|---|---|
| Density | 7.83 | g/cm³ |
| Modulus of elasticity | 210 | GPa |
| Machinability | Good in the +A and +N conditions | |

For weight estimating, 28Mn6 runs at 7.83 kg per litre. A Ø400 × 1000 mm forged bar is about 984 kg.

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## Heat treatment and forging parameters

| Operation | Temperature | Cooling / notes |
|---|---|---|
| Hot forging | 1050–850 °C | Do not finish below 850 °C; slow cool in still air or in the furnace for heavy sections |
| Normalising | 850–890 °C | Air cool |
| Soft annealing | 650–700 °C | Furnace cool; gives max 223 HBW |
| Hardening | 830–870 °C | Water or oil quench |
| Tempering | 540–680 °C | Air cool; selected within the range to achieve the specified strength band |
| Stress relieving | approx. 650 °C | Hold 1–2 h, air cool; used after rough machining to limit distortion |

Every 28Mn6 forging is normalised after the final forging operation. Rough machining follows, then quenching and tempering where +QT is ordered. Test pieces are cut from prolongations on the forging itself rather than from a separate coupon.

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## Equivalent grades

Nearest known equivalents, for guidance only.

| Standard / country | Designation | Closeness |
|---|---|---|
| EN (Europe) | 28Mn6 / 1.1170 | Reference grade |
| ISO | 28Mn6 | Identical designation |
| SAE / AISI (USA) | 1330, UNS G13300 | Nearest equivalent |
| JIS (Japan) | SMn433 | Nearest equivalent |
| BS (UK) | 150M28 | Nearest equivalent |
| AFNOR (France) | 20M5 | Nearest equivalent |
| GB (China) | 30Mn2 | Similar, verify composition |
| GOST (Russia) | 30G2 | Similar, verify composition |
| DIN (superseded) | 28Mn6 | Same designation |

Composition limits, permitted residuals and test requirements differ between standards. Send the standard called up on your drawing and we will confirm in writing whether 28Mn6 meets it.

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## 28Mn6 forgings we manufacture

All items are forged open-die from a 28Mn6 ingot or continuous-cast bloom, to drawing or to a dimensioned sketch.

| Product form | Size range |
|---|---|
| Forged round bars and rods | Ø 80–1200 mm, length to 12 000 mm. Also square, rectangular, flat and hexagonal sections |
| Forged hollow bars, sleeves, bushings | OD 100–2500 mm, ID from 60 mm, length to 6000 mm |
| Forged cylinders, casings, shells, barrels | OD to 2500 mm |
| Seamless rolled rings | OD 200–4000 mm, height to 1500 mm, wall from 30 mm |
| Forged rings and flanges | OD 100–3000 mm |
| Forged discs, blocks, plates | Ø 200–2500 mm, thickness 50–800 mm |
| Gear shafts, pinion shafts, spindles | Ø 100–1200 mm, length to 10 000 mm |
| Hubs, housings, custom shapes | To drawing; single piece weight approximately 50 kg to 30 tonnes |

To quote we need the product form, finished dimensions with machining allowance, delivery condition (+A, +N or +QT), quantity and certificate type.

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## Manufacturing process and inspection

Electric-arc melted and ladle-refined steel is cast to ingot or bloom, heated to 1150–1200 °C, then upset and drawn on the open-die press to the required reduction ratio and finished above 850 °C. Rings are pierced and rolled on the ring mill.

Testing available:

- Chemical analysis by optical emission spectrometry, ladle and product
- Tensile, yield, elongation and reduction of area at ambient temperature
- Charpy V-notch impact energy, ambient or low temperature to −40 °C
- Brinell hardness survey, and Jominy end-quench where +H is ordered
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388
- Magnetic particle and dye penetrant inspection to EN 10228-1 / ASTM E709
- Grain size, macro-etch and non-metallic inclusion rating on request
- Dimensional report against the drawing

Standard supply is an EN 10204 3.1 inspection certificate. EN 10204 3.2 countersigned by SGS, BV, TÜV, Lloyd's Register or the customer's own inspector is available when specified at order.

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## Applications

28Mn6 is stronger and more hardenable than a plain carbon steel, and cheaper and more weldable than a chromium-molybdenum steel.

- **General mechanical engineering.** Drive shafts, couplings, levers, pins, connecting parts and moderately stressed machine components.
- **Gearboxes and transmissions.** Gear blanks, pinion shafts and spindles where tooth loading is moderate and the part is through-hardened rather than case-hardened.
- **Automotive and commercial vehicle.** Axle parts, steering components and forged fittings.
- **Pressure equipment at low temperature.** Welded vessel components requiring notch toughness below ambient.
- **Wind, mining and heavy plant.** Ring blanks, hubs, housings and large discs where the section is moderate enough for manganese hardenability to reach the core.

For heavy sections, high loading or service above about 350 °C, a Cr-Mo or Ni-Cr-Mo grade is normally specified instead: 42CrMo4, 34CrMo4, AISI 4140, 34CrNiMo6, AISI 4340, 18CrNiMo7-6.

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## Frequently asked questions

**What is 28Mn6 equivalent to?**
The closest US grade is SAE/AISI 1330 (UNS G13300). Other near equivalents are JIS SMn433 in Japan, BS 150M28 in the UK, AFNOR 20M5 in France, GB 30Mn2 in China and GOST 30G2 in Russia. None of these is chemically identical to 28Mn6, because the manganese and residual limits differ.

**What is the material number for 28Mn6?**
1.1170. EN 10083-2:2006 classifies it as a non-alloy quality steel for quenching and tempering, because manganese below 1.65 % is not counted as an alloying addition under EN 10020.

**Can 28Mn6 be welded?**
Yes. The carbon equivalent normally falls in the CEV 0.55–0.65 range, so preheat is required, commonly 150–250 °C depending on section thickness and restraint, with low-hydrogen consumables and post-weld heat treatment at about 600–650 °C. Welding a quenched and tempered forging softens the heat-affected zone.

**What is the tensile strength of 28Mn6?**
In the normalised condition the minimum tensile strength is 630 MPa up to 16 mm ruling section, falling to 540 MPa at 500–1000 mm. Quenched and tempered, it runs 800–950 MPa up to 16 mm and 540–690 MPa at 250–500 mm.

**What is the forging temperature for 28Mn6?**
1050 °C down to 850 °C. Finishing below 850 °C risks cracking and leaves an uneven grain structure that normalising will not fully correct.

**Is 28Mn6 a case-hardening steel?**
No. At 0.25–0.32 % carbon it is a through-hardening quench-and-temper grade. Carburised gears are normally made in 18CrNiMo7-6, 17CrNiMo6 or AISI 4820.

**Who supplies 28Mn6 forgings in China?**
Jiangyin Jiangnan Metal Co., Ltd. manufactures 28Mn6 / 1.1170 open-die forgings at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Product forms include forged bars, hollow bars and sleeves, seamless rolled rings, forged rings, discs, blocks and gear shafts, from about 50 kg to 30 tonnes per piece, with EN 10204 3.1 or 3.2 certificates. Enquiries: sales@steelforgepieces.com, +86 189 2135 9659.

**What is the minimum order quantity for a 28Mn6 forging?**
One piece. Open-die forging has no die cost, so single prototype shafts and ring blanks are normal work.

**How long does a 28Mn6 forging take?**
Typically 25–40 days from order confirmation for a normalised forging, and longer where quenching and tempering, heavy machining or third-party witness inspection is involved.

**Can you supply 28Mn6 rough machined or finish machined?**
Yes. We supply as-forged with machining allowance, rough machined to a clean-up cut, or finish machined to drawing tolerance.

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## Contact

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone / WhatsApp: +86 189 2135 9659
Email: sales@steelforgepieces.com
Website: https://www.steelforgepieces.com/

Property values are the limit values of EN 10083-2:2006. Heat-treatment parameters follow normal mill practice for the grade. Figures are given for guidance and are not a warranty of fitness for a particular purpose. The mill certificate supplied with the order is the governing document.