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

Q: What is 28Mn6 steel?

28Mn6 is a manganese-bearing quenched and tempered engineering steel listed in EN 10083-2 under Werkstoff number 1.1170. It contains 0.25–0.32% carbon and 1.30–1.65% manganese, with chromium, molybdenum and nickel present only as residuals capped at 0.63% combined. In the quenched and tempered condition it reaches 800–950 MPa tensile strength in sections below 16 mm.

Q: Is 28Mn6 an alloy steel or a carbon steel?

Under EN 10020 it is classified as a non-alloy special steel, because 1.65% manganese is exactly the boundary between non-alloy and alloy steel. On the shop floor it behaves like a lean alloy steel and is bought alongside 34CrMo4 and 42CrMo4, which is why this site lists it under alloy steel. On a purchase order the classification does not matter; the designation 28Mn6 or 1.1170 does.

Q: What is the American equivalent of 28Mn6?

SAE / AISI 1330, UNS G13300. The carbon and manganese ranges overlap closely and both grades are used for the same duty. The UK designation is 150M28 and the French one is 20M5; both are close without being identical. Order to 28Mn6 / 1.1170 and ask for dual certification where the drawing calls out SAE 1330.

Q: What are the mechanical properties of 28Mn6 in the quenched and tempered condition?

Below 16 mm diameter: 800–950 MPa tensile strength, 590 MPa minimum 0.2% proof stress, 13% minimum elongation and 35 J minimum ISO-V impact energy. From 16 to 40 mm: 700–850 MPa with 490 MPa proof stress and 15% elongation. From 40 to 100 mm: 650–800 MPa with 440 MPa proof stress and 16% elongation.

Q: How large a section can be quenched and tempered in 28Mn6?

About 100 mm ruling section. Above that no +QT minima are quoted, because the core does not transform fast enough for the properties to be met. Heavier open-die forgings in this grade are supplied normalised, where the tensile minimum falls from 630 MPa at 16 mm to 540 MPa at 1,000 mm. If quenched and tempered properties are needed in a heavier section, move to 42CrMo4 or 34CrNiMo6.

Q: At what temperature is 28Mn6 forged?

Between 1,100 °C and 850 °C (2,012–1,562 °F). Forging must finish above 850 °C and the part is then cooled slowly in sand, ash or a furnace. 28Mn6 is sensitive to overheating and to surface decarburisation, so time above about 1,150 °C is kept short. The forging is normalised at 850–890 °C afterwards to refine the grain.

Q: Can 28Mn6 be welded?

Yes, with precautions. The carbon equivalent CEV is typically 0.55–0.70, which places the grade in the conditional weldability band. Preheat from 200 °C (392 °F), use low-hydrogen consumables, control the interpass temperature and apply post-weld heat treatment on thick sections. Welding a part that has already been quenched and tempered destroys the heat-treated properties in the weld zone.

Q: Can 28Mn6 be carburised or case hardened?

Yes. At 0.25–0.32% carbon it is low enough to carburise, and the manganese content gives a strong core, so it is used for carburised parts that need high core strength, such as journals and rear axle shafts on mining and lifting equipment. Where a deeper case with higher core toughness is needed, 18CrNiMo7-6 or 17CrNiMo6 are the usual alternatives.

Q: What is the difference between 28Mn6 and 42CrMo4?

42CrMo4 carries more carbon plus deliberate chromium and molybdenum, so it through-hardens to about 250 mm and reaches 1,000–1,200 MPa tensile strength. 28Mn6 reaches 800–950 MPa and through-hardens to about 100 mm, but costs less because it has no deliberate alloy additions. Choose 28Mn6 for medium sections where 800 MPa is enough, and 42CrMo4 for heavy or fatigue-critical parts.

Q: What delivery conditions can 28Mn6 forgings be supplied in?

+U untreated, +A soft annealed at 650–700 °C, +N normalised at 850–890 °C, +QT quenched from 830–870 °C and tempered at 540–680 °C, +S treated for cold shearability below 255 HBW, and +SR stress relieved. State the condition and the ruling section on the order: the same forging differs by more than 400 MPa in tensile strength between +A and +QT.

28Mn6 / 1.1170 at a glance

EN chemical designation: 28Mn6
Werkstoff (W.Nr.): 1.1170
Steel group: Quenched and tempered engineering steel, manganese type
Classification, EN 10020: Non-alloy special steel (manganese is capped at 1.65%, the alloy-steel boundary)
Governing standard: EN 10083-1 and EN 10083-2 (technical delivery conditions); ISO 683-1
Standard for open-die forgings: EN 10250-2, open die steel forgings for general engineering purposes, non-alloy quality and special steels
Carbon: 0.25–0.32%
Manganese: 1.30–1.65%
Tensile strength, +QT: 800–950 MPa (d < 16 mm), 650–800 MPa (d 40–100 mm)
Tensile strength, +N: 630 MPa min (t ≤ 16 mm) falling to 540 MPa min at 1,000 mm
Usual delivery conditions: +N normalised, +QT quenched and tempered, +A soft annealed, +S treated for shearability
Forging temperature: 1,100–850 °C (2,012–1,562 °F)
Weldability: Conditional. CEV about 0.55–0.70, so preheat from 200 °C (392 °F)
Nearest US grade: SAE / AISI 1330
Product forms we forge: Rolled rings, shafts, discs, blocks, sleeves, hollow bars, flanges, round and flat bars
Certification: EN 10204 3.1 as standard; 3.2 third-party witnessed on request
Forged by: Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu Province, China

What 28Mn6 is, and when to specify it

28Mn6 sits between the plain carbon quenched and tempered steels (C35, C45, C60) and the chromium-molybdenum grades (34CrMo4, 42CrMo4). It is essentially a carbon steel with the manganese pushed up to about 1.5%. Manganese lowers the critical cooling rate, so a section that would only reach the core in water as C45 will through-harden in oil as 28Mn6, at a fraction of the cost of adding chromium and molybdenum.

Section size sets the limit. Full quenched and tempered properties are specified only to about 100 mm ruling section. Above that the standard stops quoting +QT minima, because the core no longer transforms fast enough. For heavy open-die forgings, that leaves two routes: accept the normalised (+N) property level, or move up to 42CrMo4 or 34CrNiMo6. We will tell you which applies to your drawing before you place the order.

Specify 28Mn6 when you need 800–950 MPa tensile strength in a part with a ruling section under about 100 mm, want reasonable weldability with preheat, and want to avoid the price of a Cr-Mo grade. Do not specify it when the section is heavy, the service temperature is elevated, or the part must be through-hardened without distortion. The grade is sensitive to overheating, to decarburisation and to temper embrittlement in the 350–500 °C tempering range.

28Mn6 is also used as a carburising steel where the case must sit on a strong core, for example journals and axle shafts on mining and lifting equipment. In that role the manganese gives core strength without the nickel content of 18CrNiMo7-6.

Chemical composition of 28Mn6 (1.1170)

Composition limits per EN 10083-2, in weight percent, for the cast (ladle) analysis. Product analysis tolerances are given in the standard and are added to these limits.

Table 1. 28Mn6 / 1.1170 chemical composition limits, weight %
Element	Min %	Max %	Function in the steel
Carbon (C)	0.25	0.32	Sets the attainable hardness and tempered strength
Manganese (Mn)	1.30	1.65	The defining addition. Raises hardenability, deoxidises, binds sulfur
Silicon (Si)	n/a	0.40	Deoxidiser; slight solid-solution strengthening
Phosphorus (P)	n/a	0.035	Residual. Held low for toughness
Sulfur (S)	n/a	0.035	Residual. Lower limits available for through-thickness ductility
Chromium (Cr)	n/a	0.40	Residual from the charge, no deliberate addition
Molybdenum (Mo)	n/a	0.10	Residual only
Nickel (Ni)	n/a	0.40	Residual only
Cr + Mo + Ni combined	n/a	0.63	Cap that keeps the grade inside the non-alloy classification

The combined Cr + Mo + Ni limit of 0.63% matters on a purchase order. Scrap-based heats can drift towards it, and a heat that exceeds it is no longer 28Mn6 even if every individual element is inside its own limit. Every forging we ship carries the ladle analysis on the certificate; product analysis on the finished part is available on request.

Mechanical properties of 28Mn6 forgings

Quenched and tempered (+QT)

These are the specified minima for the heat-treated condition, by ruling section. These are the values a certificate has to meet; test results normally come out above them. No figures are quoted above roughly 100 mm diameter, because the grade does not reliably through-harden at that section.

Table 2. 28Mn6 mechanical properties, quenched and tempered condition (+QT)
Property	d < 16 mm	d 16–40 mm	d 40–100 mm	d 100–160 mm	d 160–250 mm
Equivalent flat thickness t	< 8 mm	8–20 mm	20–60 mm	60–100 mm	100–160 mm
0.2% proof stress R_p0.2, min	590 MPa	490 MPa	440 MPa	n/a	n/a
Tensile strength R_m	800–950 MPa	700–850 MPa	650–800 MPa	n/a	n/a
Elongation A₅, min	13 %	15 %	16 %	n/a	n/a
Reduction of area Z, min	40 %	45 %	50 %	n/a	n/a
Impact energy KV (ISO-V), min	35 J	40 J	40 J	n/a	n/a

In imperial units the top row reads 116–138 ksi tensile with 85.6 ksi minimum proof stress; the 40–100 mm band reads 94–116 ksi tensile with 63.8 ksi proof stress.

Normalised (+N)

Normalising is the usual delivery condition for heavy open-die forgings in this grade, because it is section-independent in a way that quenching is not. The first three columns follow EN 10083-2; the two heaviest bands follow the open-die forging standard EN 10250-2, which is the one that applies to most of what we make.

Table 3. 28Mn6 mechanical properties, normalised condition (+N), minimum values
Nominal thickness	to 16 mm	16–100 mm	100–250 mm	250–500 mm	500–1000 mm
Tensile strength R_m, min	630 MPa	600 MPa	570 MPa	540 MPa	540 MPa
Upper yield R_e / R_p0.2, min	345 MPa	310 MPa	290 MPa	270 MPa	260 MPa
Elongation A, min (L_o = 5.65 √S_o)	17 %	18 %	18 %	n/a	n/a

Published mill data sheets quote 590 MPa minimum tensile in the 100–250 mm band against the 570 MPa shown here. The difference comes from which standard and product form is cited; the steel is the same. Where the number is contractual, state the standard and edition on the order and the certificate will be issued against it.

Hardness and impact

Table 4. 28Mn6 hardness in the annealed and shear-treated conditions, and room-temperature impact energy
Condition	Value	Meaning
+S, treated for cold shearability	255 HBW max	Soft enough to be cold sheared or cropped before forging
+A, soft annealed	223 HBW max	Softest supply condition, for machining or cold work before heat treatment
+QT, quenched and tempered	≈ 190–240 HBW at 650–800 MPa; ≈ 235–285 HBW at 800–950 MPa	Hardness tracks the strength band, roughly R_m/3.4. Where possible put the strength band on the drawing and leave hardness as a check
KV impact, +QT, +20 °C	35–40 J min	ISO-V notch, transverse or longitudinal as agreed

Delivery condition symbols used with 28Mn6

The suffix on a 28Mn6 order changes the properties more than any other single variable. These are the symbols defined in EN 10083-1 and the ones we quote against.

Table 5. EN 10083 delivery condition symbols and what they mean for a 28Mn6 forging
Symbol	Condition	What we do	Typical use
+U	Untreated	Forged and air cooled, no subsequent heat treatment	Blanks that the customer will heat treat after machining
+A	Soft annealed	650–700 °C, furnace cooled	Maximum machinability, cold forming
+N	Normalised	850–890 °C, air cooled	Heavy forgings, uniform grain, stable properties through section
+QT	Quenched and tempered	830–870 °C quench in oil or water, temper 540–680 °C, air cooled	Shafts, gears and highly loaded parts under about 100 mm section
+S	Treated for shearability	Heat treated to below 255 HBW	Bar that will be cold sheared into billets
+SR	Stress relieved	Sub-critical soak after rough machining, slow cooled	Long shafts and thin rings that must stay straight after finishing

If a drawing says only "28Mn6", it is incomplete. A forging in +A and the same forging in +QT differ by more than 400 MPa in tensile strength. Always state the delivery condition, the ruling section the properties are to be met at, and where the test piece is to be taken from.

Physical properties of 28Mn6

28Mn6 is a ferritic-pearlitic or tempered martensitic carbon-manganese steel, and its physical constants are close to those of any low-alloy steel. Use these for design screening. They are nominal values; the certificate carries the tested ones.

Table 6. Nominal physical properties of 28Mn6 / 1.1170 at 20 °C unless stated
Property	Metric	Imperial
Density	7.85 g/cm³	0.284 lb/in³
Modulus of elasticity	210 GPa	30.5 × 10⁶ psi
Shear modulus	81 GPa	11.7 × 10⁶ psi
Poisson's ratio	0.29	0.29
Thermal conductivity	≈ 44 W/m·K	≈ 305 Btu·in/ft²·h·°F
Specific heat capacity	≈ 470 J/kg·K	≈ 0.11 Btu/lb·°F
Mean thermal expansion, 20–100 °C	≈ 12.0 µm/m·K	≈ 6.7 × 10⁻⁶ in/in·°F
Electrical resistivity	≈ 0.19 µΩ·m	≈ 114 Ω·circ mil/ft
Magnetic response	Ferromagnetic in every delivery condition
Approximate Ac₁ / Ac₃	≈ 715 °C / ≈ 810 °C. Literature values for guidance; confirm by dilatometry if the cycle is critical

Forging and heat treatment of 28Mn6

Hot working and heat treatment cycle

Table 7. Temperature ranges for hot working and heat treating 28Mn6 / 1.1170
Operation	Temperature	Cooling
Forging / hot rolling	1,100 to 850 °C (2,012 to 1,562 °F)	Slow cool in sand, ash or furnace
Normalising	850–890 °C (1,562–1,634 °F)	Still air
Soft annealing	650–700 °C (1,202–1,292 °F)	Furnace, slow
Hardening (austenitising)	830–870 °C (1,526–1,598 °F)	Oil, or water for light sections
Tempering	540–680 °C (1,004–1,256 °F)	Air
Stress relieving	550–650 °C (1,022–1,202 °F)	Furnace to below 300 °C, then air

Practical points when forging 28Mn6

Finish above 850 °C, then cool slowly. Finishing too cold leaves residual strain and risks cracking; cooling too fast after forging can produce bainite in heavy sections, which then resists the anneal.
Do not overheat. 28Mn6 is sensitive to overheating and to surface decarburisation. Soaking above about 1,150 °C coarsens the grain, and the coarse structure survives into the finished part unless it is normalised out.
Temper above 500 °C. Like most manganese steels, 28Mn6 is prone to temper embrittlement if it is tempered in, or cooled slowly through, roughly 350–500 °C. Tempering in the 540–680 °C window and cooling in air avoids it.

The finished forging is normalised as a matter of course before any quench and temper cycle, so that the properties are developed from a uniform, refined grain instead of the as-forged structure.

28Mn6 equivalent grades and cross-reference

28Mn6 carries the same or a very close designation in most systems. Rows marked nearest are close in chemistry and intended use without being identical, and do not amount to a substitution approval.

Table 8. International designations equivalent or closest to 28Mn6 / 1.1170
System / country	Designation	Match
EN / DIN (Europe, Germany)	28Mn6, Werkstoff 1.1170	Identical
ISO	28Mn6 (ISO 683-1)	Identical
SAE / AISI (USA)	1330 (also 1330H for hardenability)	Equivalent
UNS (USA)	G13300	Equivalent
AFNOR (France)	28Mn6, 20M5	Equivalent
BS (UK)	150M28, 150M19	Nearest
UNI (Italy)	28Mn6	Identical
JIS (Japan)	SMn433, SMn438	Nearest
GB (China)	30Mn2 (GB/T 3077), 28Mn6 (imported designation)	Nearest
GOST (Russia)	30G2, 35KHM family	Nearest

Where a design registration, code stamp or third-party approval is involved, order to the EN name and Werkstoff number and let the certificate carry the equivalence. We can dual-certify a heat against 28Mn6 and SAE 1330 when the chemistry falls inside both windows, which is the usual case.

28Mn6 vs C45 vs 42CrMo4: how to choose

These three grades cover most general engineering forgings, and drawings often move between them late in a project. They differ in hardenability, in the maximum section that can be through-hardened, and in price.

Table 9. Comparison of 28Mn6, C45 and 42CrMo4 for open-die forgings
Criterion	C45 / 1.0503	28Mn6 / 1.1170	42CrMo4 / 1.7225
Type	Plain carbon	Carbon + 1.5% manganese	Chromium-molybdenum alloy
Carbon	0.42–0.50%	0.25–0.32%	0.38–0.45%
Tensile, +QT, small section	700–850 MPa	800–950 MPa	1,000–1,200 MPa
Practical through-hardening limit	≈ 40 mm	≈ 100 mm	≈ 250 mm and beyond
Quench medium	Water	Oil, water for light sections	Oil
Weldability	Poor to conditional	Conditional, preheat 200 °C	Conditional, preheat and PWHT
Relative material cost	Lowest	Low	Higher
Choose it when	Light sections, low cost, hardness is enough	Medium sections need real toughness with strength, at near-carbon-steel cost	Heavy sections, fatigue duty, or the drawing calls for 1,000 MPa

Below about 40 mm, C45 is usually enough. Between 40 and 100 mm, 28Mn6 buys hardenability without buying alloy content. Above 100 mm, or where fatigue governs, use 42CrMo4 or 34CrNiMo6.

Standards that apply to 28Mn6 forgings

Table 10. Standards referenced when ordering 28Mn6 / 1.1170 open-die forgings
Standard	Scope
EN 10083-1	Steels for quenching and tempering. General technical delivery conditions, including the +N, +QT, +A and +S condition symbols
EN 10083-2	Technical delivery conditions for non-alloy steels. Lists 28Mn6 chemistry and mechanical property tables
EN 10250-2	Open die steel forgings for general engineering purposes, non-alloy quality and special steels. The dimensional and property standard for most of our work in this grade
ISO 683-1	Heat-treatable steels, international equivalent listing for 28Mn6
EN 10204	Inspection documents. Type 3.1 as standard, type 3.2 witnessed by TÜV, BV, LR, SGS or DNV on request
EN 10228-1 / -3	Non-destructive testing of steel forgings: magnetic particle and ultrasonic examination
SEP 1921	Ultrasonic acceptance classes commonly specified for forged bars and rings
ASTM A388	Ultrasonic examination of heavy steel forgings, where a US specification is preferred
ISO 6892-1 / ISO 148-1	Tensile testing and Charpy V-notch impact testing methods
ASTM E112	Grain size determination, where the drawing sets a grain size requirement

28Mn6 forgings we produce

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory. Everything below is forged to the customer's drawing or dimensional sketch. Open-die work needs no dies, so there is no tooling charge and no piece minimum, and one-off or prototype quantities are economic.

Product forms open-die forged in 28Mn6 / 1.1170 by Jiangyin Jiangnan Metal Co., Ltd.

Seamless rolled ringsRing rolled, no weld seam. Rectangular or profiled section, including gear ring blanks.
Forged shafts and spindlesStraight, stepped and eccentric shafts, pinion shafts, crankshaft blanks.
Discs, blocks and platesUpset forged discs, die blocks, flats and rectangular blocks.
Round, square, flat and hex barsForged and peeled or rough turned, cut to length.
Hollow bars and sleevesTrepanned or expanded hollows, bushes, cylinders, casings and shells.
Forged flangesWeld neck, slip-on, blind and long weld neck, to drawing or to ASME B16.5 / B16.47.
Tube sheetsForged and drilled tube sheets for shell-and-tube exchangers.
Hubs, housings and couplingsUpset forged hubs, gear couplings and machine housings.

Size and weight capability in 28Mn6

Table 11. Typical open-die forging capability for 28Mn6 / 1.1170
Product form	Dimensional range	Unit weight
Seamless rolled rings	OD 200–6,000 mm, height to 1,000 mm	20–15,000 kg
Round bars and billets	Ø 80–1,000 mm, length to 6,000 mm	10–12,000 kg
Discs, blanks, tube sheets	Ø 200–3,000 mm, thickness to 800 mm	30–15,000 kg
Shafts and spindles	Length to 6,000 mm	to 15,000 kg
Hollow bars and sleeves	OD 150–1,500 mm, bore from 60 mm	to 10,000 kg
Blocks and flats	Length to 6,000 mm	to 15,000 kg
Overall envelope	80–6,000 mm across all forms	10–15,000 kg

Plant: 1, 3, 5 and 9 tonne forging hammers, a 5,000 tonne hydraulic press and ring rolling mills. Machining allowance is normally 6–20 mm per surface depending on section size, unless the drawing states otherwise. Finish-machined parts to print are also supplied.

How a 28Mn6 forging is made here

Steel supply and verification Continuously cast or ingot material to EN 10083-2. Heat chemistry is checked on a spectrometer against the 28Mn6 window, including the Cr + Mo + Ni ≤ 0.63% cap, before anything is heated.
Heating Soaked to 1,100 °C with a controlled ramp. Time at temperature is set by section thickness, kept short enough to avoid grain coarsening and decarburisation.
Open-die forging Upset and drawn on hammers or the 5,000 t press to a controlled reduction ratio, closing porosity and producing grain flow that follows the part contour. Rings are ring rolled seamless.
Controlled cooling Cooled slowly in sand, ash or furnace from the finish temperature, so no untempered transformation product is trapped in heavy sections.
Normalising 850–890 °C, air cooled, to refine and homogenise the grain before any further treatment.
Quench and temper, if specified Austenitise 830–870 °C, quench in oil or water, temper 540–680 °C and air cool. Test pieces are taken at the ruling section stated on the drawing.
Rough or finish machining Turned, bored, faced and drilled to the drawing, with the agreed allowance or to final dimensions.
Testing and NDT Tensile, impact and hardness testing; ultrasonic examination to EN 10228-3, SEP 1921 or ASTM A388; magnetic particle inspection to EN 10228-1.
Certification and despatch EN 10204 3.1 certificate as standard, 3.2 with third-party witness on request. Hard stamped with heat number, preserved and packed for sea or air freight.

Where 28Mn6 forgings are used

Table 12. Typical applications for 28Mn6 / 1.1170 forgings by industry
Industry	Components forged in 28Mn6
Automotive and commercial vehicle	Axle shafts, steering knuckle blanks, connecting rods, hub forgings, high-strength fasteners
General mechanical engineering	Transmission shafts, gear blanks, couplings, levers, machine housings, pinion shafts
Mining, lifting and earthmoving	Crane and excavator journals, sheave and pulley forgings, track pins, carburised rear axles
Hydraulics and pneumatics	Cylinder end caps, piston rods, gland nuts, forged manifold blocks
Pumps and compressors	Shafts, impeller hubs, casings, crankshafts for reciprocating compressors
Rail and heavy structures	Draw gear components, buffer parts, forged pins and links
Bearings and seals	Rolled rings for bearing housings, seal carriers and spacer rings

Most of these parts are machined all over, carry a working load, and are too large to make economically from C45 bar, while not justifying the price of a chromium-molybdenum grade.

Testing, inspection and certification

Chemical analysis. Spectrometric heat analysis as standard; product analysis on the finished forging on request.
Mechanical testing. Room-temperature tensile and elongation to ISO 6892-1; Charpy V-notch impact to ISO 148-1, at +20 °C or at a lower test temperature on request.
Hardness. Brinell survey, number and position of readings as agreed on the drawing.
Ultrasonic testing. EN 10228-3, SEP 1921 class C/D/E, ASTM A388, or the customer's own acceptance class.
Surface NDT. Magnetic particle examination to EN 10228-1; liquid penetrant to ASTM E165 where specified.
Grain size and microstructure. To ASTM E112, with photomicrographs when the specification calls for them.
Dimensional inspection. Full dimensional report against the drawing before despatch.
Certification. EN 10204 3.1 mill test certificate as standard, showing heat number, chemical analysis, heat treatment record, mechanical results and NDT results. EN 10204 3.2 witnessed by TÜV, BV, LR, SGS or DNV on request at order stage. Full heat traceability and hard stamping.
Quality system. ISO 9001:2015.

Frequently asked questions about 28Mn6 / 1.1170

What is 28Mn6 steel?

28Mn6 is a manganese-bearing quenched and tempered engineering steel listed in EN 10083-2 under Werkstoff number 1.1170. It contains 0.25–0.32% carbon and 1.30–1.65% manganese, with chromium, molybdenum and nickel present only as residuals capped at 0.63% combined. In the quenched and tempered condition it reaches 800–950 MPa tensile strength in sections below 16 mm.

Is 28Mn6 an alloy steel or a carbon steel?

Under EN 10020 it is classified as a non-alloy special steel, because 1.65% manganese is exactly the boundary between non-alloy and alloy steel. On the shop floor it behaves like a lean alloy steel and is bought alongside 34CrMo4 and 42CrMo4, which is why this site lists it under alloy steel. On a purchase order the classification does not matter; the designation 28Mn6 or 1.1170 does.

What is the American equivalent of 28Mn6?

SAE / AISI 1330, UNS G13300. The carbon and manganese ranges overlap closely and both grades are used for the same duty. The UK designation is 150M28 and the French one is 20M5; both are close without being identical. Order to 28Mn6 / 1.1170 and ask for dual certification where the drawing calls out SAE 1330.

What are the mechanical properties of 28Mn6 in the quenched and tempered condition?

Below 16 mm diameter: 800–950 MPa tensile strength, 590 MPa minimum 0.2% proof stress, 13% minimum elongation and 35 J minimum ISO-V impact energy. From 16 to 40 mm: 700–850 MPa with 490 MPa proof stress and 15% elongation. From 40 to 100 mm: 650–800 MPa with 440 MPa proof stress and 16% elongation.

How large a section can be quenched and tempered in 28Mn6?

About 100 mm ruling section. Above that no +QT minima are quoted, because the core does not transform fast enough for the properties to be met. Heavier open-die forgings in this grade are supplied normalised, where the tensile minimum falls from 630 MPa at 16 mm to 540 MPa at 1,000 mm. If quenched and tempered properties are needed in a heavier section, move to 42CrMo4 or 34CrNiMo6.

At what temperature is 28Mn6 forged?

Between 1,100 °C and 850 °C (2,012–1,562 °F). Forging must finish above 850 °C and the part is then cooled slowly in sand, ash or a furnace. 28Mn6 is sensitive to overheating and to surface decarburisation, so time above about 1,150 °C is kept short. The forging is normalised at 850–890 °C afterwards to refine the grain.

Can 28Mn6 be welded?

Yes, with precautions. The carbon equivalent CEV is typically 0.55–0.70, which places the grade in the conditional weldability band. Preheat from 200 °C (392 °F), use low-hydrogen consumables, control the interpass temperature and apply post-weld heat treatment on thick sections. Welding a part that has already been quenched and tempered destroys the heat-treated properties in the weld zone.

Can 28Mn6 be carburised or case hardened?

Yes. At 0.25–0.32% carbon it is low enough to carburise, and the manganese content gives a strong core, so it is used for carburised parts that need high core strength, such as journals and rear axle shafts on mining and lifting equipment. Where a deeper case with higher core toughness is needed, 18CrNiMo7-6 or 17CrNiMo6 are the usual alternatives.

What is the difference between 28Mn6 and 42CrMo4?

42CrMo4 carries more carbon plus deliberate chromium and molybdenum, so it through-hardens to about 250 mm and reaches 1,000–1,200 MPa tensile strength. 28Mn6 reaches 800–950 MPa and through-hardens to about 100 mm, but costs less because it has no deliberate alloy additions. Choose 28Mn6 for medium sections where 800 MPa is enough, and 42CrMo4 for heavy or fatigue-critical parts.

What delivery conditions can 28Mn6 forgings be supplied in?

+U untreated, +A soft annealed at 650–700 °C, +N normalised at 850–890 °C, +QT quenched from 830–870 °C and tempered at 540–680 °C, +S treated for cold shearability below 255 HBW, and +SR stress relieved. State the condition and the ruling section on the order: the same forging differs by more than 400 MPa in tensile strength between +A and +QT.

Do you supply a mill test certificate with 28Mn6 forgings?

Every forging ships with an EN 10204 3.1 mill test certificate showing heat number, ladle analysis, heat treatment record, mechanical test results and NDT results. EN 10204 3.2 certification witnessed by a third party such as TÜV, BV, LR, SGS or DNV is available when requested at order stage. Hard stamping and full heat traceability are standard.

What sizes of 28Mn6 forgings can you supply?

Seamless rolled rings from 200 to 6,000 mm outside diameter, round bars from 80 to 1,000 mm diameter and up to 6,000 mm long, discs and tube sheets to 3,000 mm diameter and 800 mm thick, and shafts to 6,000 mm long. Unit weights run from 10 kg to 15,000 kg. The plant runs 1, 3, 5 and 9 tonne forging hammers, a 5,000 tonne hydraulic press and ring rolling mills.

What is the lead time for a 28Mn6 forging?

Typically 25 to 40 days for rings, discs, bars and shafts when the material is in stock, counted from drawing approval. Parts that need a new melt, heavy machining, long heat treatment cycles or third-party witnessed inspection take longer. Send the drawing and a firm date is confirmed with the quotation.

Who supplies open-die forged 28Mn6 (1.1170) parts in China?

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It forges 28Mn6 / 1.1170 into seamless rolled rings, shafts, discs, blocks, sleeves, hollow bars and round bars to customer drawings, heat treats and machines in house, and exports worldwide. Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.

Request a quotation for 28Mn6 forgings

Send a drawing, a sketch, or simply the dimensions and quantity. Open-die forgings in 28Mn6 are quoted with no tooling charge and no piece minimum.

Useful details if you have them: grade and standard (28Mn6 / 1.1170 / EN 10083-2), product form, dimensions with machining allowance, quantity, delivery condition (+N, +QT, +A), NDT class, certificate type (EN 10204 3.1 or 3.2) and required delivery date.

Company: Jiangyin Jiangnan Metal Co., Ltd.
Business: Open-die forging factory
Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone / WhatsApp: +86 189 2135 9659 (0086-189-2135-9659)
Email: sales@steelforgepieces.com
Website: www.steelforgepieces.com

Email your drawing for a quote Call +86 189 2135 9659

Sources, scope and how to cite this page

Composition and property tables on this page are compiled from EN 10083-1 and EN 10083-2, from EN 10250-2 for open-die forgings, and from published mill data sheets for Werkstoff 1.1170. Values are for guidance in design and enquiry. The mill test certificate issued with each forging is the document that governs acceptance.

Suggested citation
Jiangyin Jiangnan Metal Co., Ltd. (2026). 28Mn6 (1.1170) forgings: composition, mechanical properties, heat treatment and open-die forging capability. Jiangyin, Jiangsu, China. Retrieved from https://www.steelforgepieces.com/Alloy-Steel/1.1170.html

Page facts. Published by Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu Province, China. Technical review by the company's metallurgical engineering team. Last updated 5 September 2026. Content may be quoted with attribution to Jiangyin Jiangnan Metal Co., Ltd.

28Mn6 (1.1170) forgings