28Mn6 (1.1170) Forgings: Bars, Rings, Shafts

28Mn6 grade 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. Enquiries: sales@steelforgepieces.com, +86 189 2135 9659.

Property values in the tables below are the minimum or limit values of EN 10083-2:2006 unless stated otherwise. Results for a specific heat are reported on the mill certificate supplied with the order.

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

Chemical composition of 28Mn6 (1.1170)

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

**Table 1.** 28Mn6 / 1.1170 chemical composition, % by weight, EN 10083-2:2006
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.

Manganese widens the hardenability band and slows ferrite formation on cooling. A 28Mn6 forging of 100 mm section therefore reaches strength levels that a C30 carbon steel of the same size cannot, without the chromium and molybdenum additions that make 42CrMo4 and 34CrMo4 dearer and harder to weld.

Mechanical properties of 28Mn6

Normalised condition (+N)

**Table 2.** 28Mn6 minimum mechanical properties, normalised (+N), by ruling section
Nominal thickness / diameter (mm)	to 16	16–100	100–250	250–500	500–1000
R_m - tensile strength, MPa min.	630	600	570	540	540
R_eH / R_p0.2 - yield strength, MPa min.	345	310	290	270	260
A - elongation, L_o = 5.65√S_o, % min.	17	18	18	—	—

Quenched and tempered condition (+QT)

**Table 3.** 28Mn6 typical mechanical properties, quenched and tempered (+QT), by ruling section
Diameter (mm)	R_p0.2 MPa min.	R_m 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. We raise this at quotation stage.

Hardness and hardenability

**Table 4.** 28Mn6 maximum Brinell hardness in the annealed and shearable delivery conditions
Delivery condition	Brinell hardness, HBW max.
+S, treated to improve shearability	255
+A, soft annealed	223

**Table 5.** 28Mn6 Jominy end-quench hardenability (+H), HRC at distance from the quenched end, 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.

Physical properties

**Table 6.** 28Mn6 physical properties at ambient temperature (typical values)
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. Quotations are based on finished forging weight plus the machining allowance shown on the drawing.

Heat treatment and forging parameters

**Table 7.** 28Mn6 recommended forging and heat-treatment 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, so the certified properties belong to the part supplied.

28Mn6 equivalent grades worldwide

**Table 8.** 28Mn6 (1.1170) international cross-reference, nearest known equivalents
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
Cross-references are for guidance only. 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.

28Mn6 forgings we manufacture

All items below are forged open-die from a 28Mn6 ingot or continuous-cast bloom, to drawing or to a dimensioned sketch. These are forged parts, not machined stock bar. The forging reduction is what produces the grain flow and internal soundness that a sawn bar does not have.

Forged round bars and rodsØ 80–1200 mm, length to 12 000 mm. Also square, rectangular, flat and hexagonal sections.
Forged hollow bars, sleeves, bushingsOD 100–2500 mm, ID from 60 mm, length to 6000 mm. Trepanned or mandrel-forged.
Forged cylinders, casings, shells, barrelsOD to 2500 mm. Pipe, tube and housing blanks for hydraulic and pressure service.
Seamless rolled ringsOD 200–4000 mm, height to 1500 mm, wall from 30 mm. Radial-axial rolled for circumferential grain flow.
Forged rings and flangesOD 100–3000 mm. Ring blanks, tube sheets, blind and weld-neck flange blanks.
Forged discs, blocks, platesØ 200–2500 mm, thickness 50–800 mm. Upset-forged for through-thickness properties.
Gear shafts, pinion shafts, spindlesØ 100–1200 mm, length to 10 000 mm. Stepped, flanged and hollow shafts, rough or finish machined.
Hubs, housings, custom shapesTo drawing. Single piece weight approximately 50 kg to 30 tonnes.

How to order

To quote we need the product form, finished dimensions with machining allowance, delivery condition (+A, +N or +QT), quantity and certificate type. Send the enquiry to sales@steelforgepieces.com or call +86 189 2135 9659.

Manufacturing process and inspection

28Mn6 forges without difficulty. Most of the quality risk lies in reheating, finishing temperature and the heat treatment that follows.

Route

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. Every piece is normalised after forging. Quenching and tempering follows where +QT is ordered.

Testing available

Chemical analysis by optical emission spectrometry, on the ladle and on the 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 when +H is ordered
Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, acceptance class agreed with you
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

Documentation

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. Third-party and witness inspection at our works is accepted. State this at enquiry stage so the test plan is agreed before production starts.

28Mn6 applications

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

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, where weldability matters more than peak strength.
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. Related grades we forge:

28Mn6 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. Treat them as substitution candidates and confirm against the specification on the drawing.

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. Weldability is one of the reasons the grade is specified. 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, so the welding procedure should be agreed before the forging is heat treated.

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. Section size is the main variable, because manganese hardenability is limited.

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. Heavy sections should cool slowly in still air or in the furnace after the last forging operation.

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. 28Mn6 gears are through-hardened or induction hardened on the tooth flanks.

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. Cost per kilogram falls with quantity mainly through furnace batching and machining setup rather than through tooling.

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. Lead time at the front end depends on raw material. If 28Mn6 is not in the melt schedule, an ingot has to be poured.

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. State which is required at enquiry, since the forging allowance and the heat-treatment sequence depend on it.

Manufacturer and contact details

Published by the manufacturer. The parts are forged in our own works.

Jiangyin Jiangnan Metal Co., Ltd.

Open-die forging factory producing forged bars, seamless rolled rings, sleeves, discs, blocks and shafts in carbon, alloy, tool and stainless steel and nickel alloys.

Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone / WhatsApp: +86 189 2135 9659
Email: sales@steelforgepieces.com
Website: www.steelforgepieces.com
Grade covered here: 28Mn6 / 1.1170 open-die forgings

Compiled by Jiangyin Jiangnan Metal Co., Ltd. Property values are the limit values of EN 10083-2:2006. Heat-treatment parameters follow normal mill practice for the grade. Last reviewed 10 September 2026. 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.