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Jiangyin Jiangnan Metal Co., Ltd. Open-die forging factory

Werkstoff 1.6580 · EN 30CrNiMo8 · AFNOR 30CND8 · BS 823M30

30CND8 Forgings

30CrNiMo8 rings, flanges, shafts, discs and bars

30CND8 is the French AFNOR name for the chromium-nickel-molybdenum quenching and tempering steel designated 30CrNiMo8 in the EN system, material number 1.6580. Two per cent chromium, two per cent nickel and 0.4 per cent molybdenum give it enough hardenability to harden through sections that leaner steels only skin-harden, at a carbon level low enough to keep impact values after tempering. Jiangyin Jiangnan Metal Co., Ltd. open-die forges 30CND8 to drawing as seamless rolled rings, forged rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets. Material is melted EAF + LF + VD and released with EN 10204 3.1 or 3.2 certification.

900 MPaMinimum Rm, forged and Q&T to 250 mm, EN 10250-3
45 HRCReached after tempering at 450 °C
5 kg–20 tSingle-piece forging weight range
4,000 mmLargest seamless rolled ring outside diameter

30CND8 at a glance

Also called
30CrNiMo8, 1.6580, 30NCD8, 823M30, SNCM431, 30Cr2Ni2Mo, 30KhN2MA
Alloy type
Cr-Ni-Mo steel for quenching and tempering, very high hardenability
Carbon
0.26 to 0.34 %
Chromium / nickel
1.80 to 2.20 % each
Standards
EN 10083-3, EN 10250-3 (open-die forgings), ISO 683-2, EN 10269, EN 10297-1, ASTM A320 grade L43
Melting route
EAF + LF + VD, ESR where the specification calls for it
Delivery condition
Quenched and tempered; also normalised, soft annealed or as forged
Density
7.85 g/cm³
Forms forged
Rings, flanges, bars, discs, shafts, sleeves, bushings, tube sheets, blocks
Supplier
Jiangyin Jiangnan Metal Co., Ltd., Jiangsu, China

What is 30CND8?

30CND8 is the AFNOR designation for the steel the EN system calls 30CrNiMo8 and the German Werkstoff system numbers 1.6580. It is a wrought low-alloy steel supplied quenched and tempered, used where a part carries high static and fatigue loads in a heavy section.

The alloy content is what makes the grade worth its price. Chromium and molybdenum push the nose of the transformation curve to the right so the centre of a thick part still transforms to martensite on an oil quench. Nickel raises toughness in the tempered structure and lowers the ductile-brittle transition. Carbon stays at 0.26 to 0.34 per cent, well below the 0.40 per cent typical of 4140 and 4340, which is why 30CND8 gives up a little peak hardness and gets back impact energy.

Hardenability is the practical reason engineers specify it. On the Jominy end-quench test to ISO 683-2, the H band for 30CND8 holds 48 HRC minimum at 1.5 mm from the quenched end and still 43 HRC minimum at 50 mm. Few quench-and-temper steels stay that hard that deep. In a 400 mm forged shaft the difference between surface and core properties is small enough to design around.

Where 30CND8 sits among quench and temper steels

42CrMo4 and 4140 sit below it. They cost less and machine more easily, but they cannot hold full properties much past 100 mm ruling section. 34CrNiMo6 sits between the two, with about half the nickel and chromium of 30CND8. Above 30CND8 are the higher-alloy and vacuum-remelted grades used in aerospace, at a step change in price. 30CND8 is the usual answer when 34CrNiMo6 has run out of section and the budget will not stretch to a remelted grade.

30CND8 designations, equivalents and standards

30CND8, 30CrNiMo8, 1.6580 and 823M30 all describe the same steel. French practice writes it either 30CND8 or 30NCD8, depending on the era of the drawing. Jiangyin Jiangnan Metal Co., Ltd. accepts enquiries under any of these names and states the customer designation on the certificate.

Cross-reference for 30CND8
SystemDesignationNotes
DIN / EN Werkstoff-Nr.1.6580Primary European material number
EN designation30CrNiMo8Used in EN 10083-3 and EN 10250-3
France, AFNOR30CND8, 30NCD8Original French designation
United Kingdom, BS 970823M30Direct equivalent
Japan, JIS G4103SNCM431Close equivalent
Italy, UNI30CrNiMo8, 30NiCrMo8Close equivalent
China, GB/T 307730Cr2Ni2MoClosest domestic grade
Russia, GOST 454330KhN2MAClose equivalent
USA, ASTMA320 grade L43Bolting for low-temperature service of this composition
Related EN grade31CrNiMo8Slightly higher carbon variant
Product standardsEN 10083-3, EN 10250-3, ISO 683-2, EN 10269, EN 10297-1Bar, open-die forgings, hot-rolled product, fasteners, seamless tube

Ordering note. EN 10083-3 and ISO 683-2 cover rolled bar. A 30CND8 forging is normally ordered to EN 10250-3 plus your drawing and acceptance criteria. State the ruling section, the tensile and impact minima, the sampling direction and the NDT class on the enquiry and they will be written into the mill certificate.

Chemical composition of 30CND8

30CND8 / 30CrNiMo8 / 1.6580 composition, weight %, cast analysis to EN 10083-3 and ISO 683-2. The aim column is the mid-range chemistry Jiangyin Jiangnan Metal melts to for forging stock.
ElementSymbolSpecified rangeTypical aim
CarbonC0.26 to 0.340.30
SiliconSi0.10 to 0.400.25
ManganeseMn0.50 to 0.800.65
ChromiumCr1.80 to 2.202.00
NickelNi1.80 to 2.202.00
MolybdenumMo0.30 to 0.500.40
CopperCu≤ 0.40
PhosphorusP≤ 0.025
SulphurS≤ 0.035
IronFebalance~93

Sulphur is capped at 0.035 per cent in the standard, but forgings for pressure, subsea or low temperature duty are normally ordered to 0.015 per cent or lower. Ask for the restricted analysis on the enquiry rather than after the heat is melted.

Mechanical properties of 30CND8

Forged and quenched and tempered, EN 10250-3

This is the table that applies to an open-die forging. L is longitudinal, T tangential.

30CND8 forged, quenched and tempered, minimum properties to EN 10250-3
Ruling section d / t (mm) Rm min (MPa) Rp0.2 min (MPa) A min L (%) A min T (%) KV min L (J) KV min T (J) HB
up to 250 / 1609007001284522271
250 / 160 to 500 / 3308506301284522253
500 / 330 to 990 / 6608005901284020240

d is diameter, t is thickness. Hardness figures are for information rather than acceptance.

Hot-rolled bar, quenched and tempered, ISO 683-2

30CND8 hot-rolled bar in the quenched and tempered condition, minimum properties to ISO 683-2, tested longitudinally at room temperature
Size d / t (mm) Rm (MPa) Rp0.2 min (MPa) A min (%) Z min (%) KV min (J)
up to 16 / 81030 to 12308501240
16 / 8 to 40 / 201030 to 1230850124030
40 / 20 to 100 / 60980 to 1180800124535
100 / 60 to 160 / 100980 to 1180800125045
160 / 100 to 250 / 160930 to 1130750125045

Tempering response

Tempering temperature is the lever that sets where the part lands. Values below are measured on 10 mm rounds quenched from 850 °C in oil, so they show the ceiling for the grade rather than what a 500 mm forging will reach at its core.

30CND8 room-temperature properties after tempering, 10 mm round oil quenched from 850 °C
Tempering temperature 450 °C500 °C 550 °C600 °C 650 °C700 °C
Hardness HB426404381347275240
Hardness HRC454341372823
Rm (MPa)1500140012901150920800
Rp0.2 (MPa)135012501090960780640
Elongation A (%)10.010.011.014.016.018.0
Reduction of area Z (%)424548505252
Impact KV (J)205060758092

Design note. Strength and toughness move in opposite directions across that table. Tempering at 450 °C buys 1500 MPa and leaves 20 J of impact energy; tempering at 600 °C trades 350 MPa for nearly four times the toughness. Fix the property you actually need on the drawing, and the tempering cycle follows from it.

Low-temperature impact behaviour

Typical Charpy V values on a 32 mm round quenched and tempered to Rm 1260 MPa, given as an indication of the transition behaviour rather than as a specification requirement:

Typical Charpy V impact energy of quenched and tempered 30CND8 against test temperature
Test temperature +20 °C0 °C −20 °C−40 °C −60 °C−80 °C
Average KV (J)664942332827

Order low-temperature impact testing explicitly if the part runs below zero. Jiangyin Jiangnan Metal Co., Ltd. tests to the temperature stated on the order and reports the individual and average values on the certificate.

Physical properties of 30CND8

30CND8 / 1.6580 physical constants at 20 °C, to DIN SEW 310
PropertyValue (metric)Value (imperial)
Density7.85 g/cm³0.284 lb/in³
Modulus of elasticity212 GPa30.7 × 106 psi
Shear modulus81 GPa11.7 × 106 psi
Thermal conductivity33.7 W/m·K19.5 Btu/hr·ft·°F
Specific heat capacity461 J/kg·K0.110 Btu/lb·°F
Electrical resistivity0.309 Ω·mm²/m30.9 µΩ·cm
Thermal expansion, 20 to 100 °Cabout 11.5 × 10−6 K−16.4 × 10−6 °F−1
Magnetic responseFerromagnetic in all delivery conditions
30CND8 transformation temperatures
Ac1Ac3Ms, martensite startMf, martensite finish
720 °C770 °C310 °C100 °C

Physical constants are typical published values for the grade. The values on your mill certificate govern for acceptance.

30CND8 forged product forms and size ranges

Jiangyin Jiangnan Metal Co., Ltd. forges 30CND8 to drawing rather than from a stock list. The ranges below cover the working envelope of the presses and the ring mill. Send a drawing and the achievable size is confirmed on the quotation.

Seamless rolled rings

Radial-axial rolled from a punched, upset blank. Grain flow follows the circumference.

OD 200 to 4,000 mm · height to 1,000 mm

Forged rings

Press-forged and bored where the section is too heavy or the ratio too short to roll.

OD 100 to 3,000 mm

Forged flanges

Weld-neck, blind, slip-on and special profiles, forged and rough machined.

50 to 3,000 mm

Round bars

Drawn under the press, straightened, peeled or turned as required.

Ø 20 to 1,200 mm · length to 12,000 mm

Discs and blanks

Upset discs for gear blanks, valve seats, closures and coupling hardware.

Ø 100 to 2,500 mm

Shafts and spindles

Stepped shafts, eccentric shafts, pinion shafts and spindles with full-length grain flow.

Ø 60 to 1,000 mm

Sleeves and bushings

Hollow forgings, trepanned or mandrel-forged to cut machining loss.

OD 100 to 2,000 mm

Tube sheets

Heavy plate-form forgings, ultrasonically tested before drilling.

to 3,000 mm · to 400 mm thick

Forged pipes and hollows

Hollow-forged and bored sections for thick-wall cylinders and pressure parts.

OD 100 to 1,500 mm

Single-piece weight: 5 kg to 20,000 kg. Also produced in this grade: valve bodies, valve stems, valve seat rings, crankshafts, gears, blocks, nozzles and bespoke open-die forged parts.

How Jiangyin Jiangnan Metal produces 30CND8 forgings

  1. Melting: EAF + LF + VD
    Electric arc melting, ladle refining and vacuum degassing. Degassing pulls hydrogen down far enough to keep heavy 30CND8 sections free of flaking, which is the usual failure mode when this grade is forged from gassy stock. ESR is added where the specification calls for it.
  2. Open-die forging: 1,050 to 880 °C
    Soak, then upset and draw to break down the as-cast structure. Reduction ratio is agreed on the order and is normally 3:1 or better. Forging finishes above 880 °C and the piece goes to controlled cooling rather than being left in still air.
  3. Ring rolling or profiling
    Ring blanks are punched, upset and rolled on the radial-axial mill so grain flow runs round the circumference. Bars, shafts and discs are drawn or upset under the press to the rough-machining envelope.
  4. Heat treatment
    Harden from 830 to 860 °C, quench in oil or polymer, temper 540 to 660 °C to the strength band on the order. Heavy sections get double tempering and an intermediate stress relief after rough machining. Furnace charts are calibrated and recorded.
  5. Rough machining
    Turned or milled to your drawing with test-piece material and a UT scanning surface left on.
  6. Testing and certification
    Spectrographic chemistry, tensile, impact and hardness testing at the sampling position agreed for the ruling section. Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388. Released with an EN 10204 3.1 mill certificate, or EN 10204 3.2 witnessed by TUV, BV, SGS or Lloyd's Register on request.

What 30CND8 forgings are used for

30CND8 is specified where the section is too heavy for 42CrMo4 or 34CrNiMo6 to reach full properties at the core, and where a fatigue or impact load rules out running the part soft. Typical forged applications:

30CND8 forgings by industry
IndustryForged componentsWhy 30CND8
Oil and gas drilling Down-hole and ultra-deep casing components, drill collars, subs, wellhead and Christmas tree parts, forged flanges Full through-hardening in thick wall sections carrying combined torque and tension
Subsea and offshore Deepwater production hardware, hubs, connectors, sleeves and bushings High strength with impact values held down to sub-zero service
Valves and flow control Valve bodies, stems, seat rings, blocks and closures for ball, gate, globe, check and plug valves Strength in the pressure envelope plus a machinable annealed condition
Power transmission Gears, gear blanks, pinion shafts, gearbox shafts, couplings, torque-carrying pins Core hardness under a case, and fatigue strength on the tooth root
Rotating equipment Seamless rolled rings, spindles, compressor rotors and shafts Circumferential grain flow from ring rolling, plus deep hardening on large diameters
Power generation Turbine and generator shafting, coupling forgings, heavy fasteners and studs Consistent properties from rim to bore on large diameters
Process and chemical plant Tube sheets, nozzles, forgings for columns, towers, preheaters and crystalliser equipment Heavy plate-form forgings with certified through-thickness properties
Marine and heavy machinery Propulsion shafting, rudder stocks, crankshafts, eccentric shafts, press and mill parts Fatigue strength and toughness in long forged sections

30CND8 compared with 42CrMo4, 34CrNiMo6, 4140 and 4340

30CND8 is usually reached for after 34CrNiMo6 has run out of ruling section. The table sets out where each grade sits.

Quench and temper steel comparison, nominal composition
GradeC %Cr % Ni %Mo % Practical ruling sectionRelative cost
30CND8 / 30CrNiMo8 0.302.002.000.40 Deepest of this group, used to 990 mm under EN 10250-3Mid to high
34CrNiMo6 / 1.6582 0.341.501.500.22 Good to roughly 250 mmMid
AISI 4340 0.400.801.800.25 Similar to 34CrNiMo6, higher peak hardnessMid
42CrMo4 / 1.7225 0.421.050.22 Falls away past about 100 mmLow
AISI 4140 0.400.950.20 Falls away past about 100 mmLow

Composition figures are nominal and given for orientation. Grade selection for a pressure or safety-critical part should be made against the applicable design code and the service conditions rather than from a summary table.

The 4340 question

Buyers often treat 30CND8 and AISI 4340 as the same steel. They are not. Nickel is close, but 30CND8 carries roughly twice the chromium and about a quarter less carbon. In service that means 30CND8 tempers to a lower peak hardness and keeps more impact energy at the same tensile level, while 4340 will reach a higher hardness on a small section. Jiangyin Jiangnan Metal Co., Ltd. quotes both, and swaps one for the other only when the design authority approves it in writing.

Machining, welding and hot working

Machining

Machine 30CND8 soft annealed at 248 HB or under for heavy stock removal, then finish in the final quenched and tempered condition. At 300 HB and above use carbide tooling, rigid setups, positive rake and a steady feed. Rough machine before the final temper where the part has deep pockets or thin webs, and stress relieve about 50 °C below the tempering temperature before finishing. Forgings are supplied rough machined so the finishing allowance is predictable.

Welding

30CND8 has a high carbon equivalent and is not a readily weldable grade. Where welding cannot be avoided, preheat to about 300 °C, hold the interpass temperature, use low-hydrogen consumables, and stress relieve after welding at about 550 °C with furnace cooling, keeping the stress relief below the original tempering temperature. Qualify the procedure before production rather than on the job.

Hot working

Forge between 1,050 and 880 °C. Do not finish below 880 °C and do not attempt to reheat and continue at the bottom of the range. Cool controlled rather than in still air after forging, then normalise or harden and temper as the order requires.

30CND8 frequently asked questions

What is material 30CND8?

30CND8 is the French AFNOR designation for a chromium-nickel-molybdenum steel for quenching and tempering, designated 30CrNiMo8 in the EN system and carrying Werkstoff material number 1.6580. It contains 0.26 to 0.34% carbon, 1.80 to 2.20% chromium, 1.80 to 2.20% nickel and 0.30 to 0.50% molybdenum. The grade is known for very high hardenability, which lets it harden through heavy sections that leaner steels cannot. Jiangyin Jiangnan Metal Co., Ltd. open-die forges 30CND8 to drawing at its works in Jiangyin, Jiangsu, China.

What is 30CND8 equivalent to?

30CND8 is equivalent to EN 30CrNiMo8, Werkstoff 1.6580, BS 823M30 in the United Kingdom, SNCM431 in Japan, 30Cr2Ni2Mo in China and 30KhN2MA in Russia. It is also written 30NCD8 in French practice, and ASTM A320 grade L43 covers bolting of this composition. Jiangyin Jiangnan Metal Co., Ltd. accepts enquiries placed under any of these designations.

What is the chemical composition of 30CND8?

30CND8 contains 0.26 to 0.34% carbon, 0.10 to 0.40% silicon, 0.50 to 0.80% manganese, 1.80 to 2.20% chromium, 1.80 to 2.20% nickel, 0.30 to 0.50% molybdenum, up to 0.025% phosphorus, up to 0.035% sulphur and up to 0.40% copper, with iron as the balance. The composition is specified in EN 10083-3 and ISO 683-2.

What mechanical properties do 30CND8 forgings have?

For open-die forgings to EN 10250-3 in the quenched and tempered condition, 30CND8 gives 900 MPa minimum tensile strength and 700 MPa minimum proof strength up to 250 mm ruling section, 850 and 630 MPa from 250 to 500 mm, and 800 and 590 MPa from 500 to 990 mm. Minimum longitudinal elongation is 12% and minimum longitudinal impact energy is 40 to 45 J. Higher strength is available on smaller sections by tempering lower, and the values on the EN 10204 certificate issued by Jiangyin Jiangnan Metal Co., Ltd. govern for acceptance.

What heat treatment does 30CND8 need?

30CND8 is hardened from 830 to 860 °C and quenched in oil or polymer, then tempered between 540 and 660 °C and cooled in air. Normalising is carried out at 870 to 880 °C with air cooling, and soft annealing at 650 to 700 °C with slow furnace cooling to give a maximum hardness of 248 HB. Stress relieving is run about 50 °C below the tempering temperature. Jiangyin Jiangnan Metal Co., Ltd. sets the tempering temperature to the strength band stated on the order.

How hard can 30CND8 be tempered?

On a 10 mm round quenched from 850 °C in oil, 30CND8 tempers to about 45 HRC and 1500 MPa tensile strength at 450 °C, 43 HRC and 1400 MPa at 500 °C, 41 HRC and 1290 MPa at 550 °C, 37 HRC and 1150 MPa at 600 °C, and 23 HRC and 800 MPa at 700 °C. Impact energy rises as hardness falls, from about 20 J at 450 °C to about 92 J at 700 °C.

Can 30CND8 replace AISI 4340?

Not directly. 30CND8 and AISI 4340 sit in the same Cr-Ni-Mo family and carry similar nickel, but 30CND8 has lower carbon, 0.26 to 0.34% against 0.38 to 0.43%, and roughly twice the chromium, 1.80 to 2.20% against 0.70 to 0.90%. 30CND8 tempers to a lower peak hardness and holds more toughness at the same strength level. Jiangyin Jiangnan Metal Co., Ltd. quotes either grade but substitutes one for the other only with written approval from the design authority.

Is 30CND8 weldable?

30CND8 has a high carbon equivalent and is not a readily weldable grade. Where welding cannot be avoided, preheat to about 300 °C, use low-hydrogen consumables, and stress relieve after welding at about 550 °C with furnace cooling, keeping the stress relief below the original tempering temperature. Qualify the procedure before production. Jiangyin Jiangnan Metal Co., Ltd. can supply the part as a single machined forging so that welded joints are avoided.

What sizes of 30CND8 forgings can you supply?

Jiangyin Jiangnan Metal Co., Ltd. forges 30CND8 seamless rolled rings from 200 mm to 4,000 mm outside diameter, forged rings from 100 mm to 3,000 mm, round bars from 20 mm to 1,200 mm diameter and up to 12,000 mm long, discs to 2,500 mm diameter, shafts from 60 mm to 1,000 mm diameter and tube sheets to 3,000 mm across and 400 mm thick. Single-piece forging weight runs from 5 kg to 20,000 kg. Parts are forged to the customer drawing rather than to a stock list.

What certification comes with 30CND8 forgings?

Every 30CND8 forging is released with an EN 10204 3.1 mill test certificate covering heat number, chemistry, mechanical properties and heat treatment records. EN 10204 3.2 certification witnessed by a third party such as TUV, BV, SGS or Lloyd's Register is available on request, as is ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, and magnetic particle or dye penetrant inspection.

What is the density of 30CND8?

The density of 30CND8 (30CrNiMo8 / 1.6580) is 7.85 g/cm³. Modulus of elasticity is about 212 GPa at 20 °C, thermal conductivity about 33.7 W/m·K, specific heat capacity about 461 J/kg·K and electrical resistivity about 0.309 Ω·mm²/m. Transformation temperatures are Ac1 720 °C and Ac3 770 °C, with martensite start at 310 °C.

How do I get a price for a 30CND8 forging?

Send the drawing or the finished dimensions, the quantity, the required specification and any test or certification requirements to sales@steelforgepieces.com, or call +86-189-2135-9659. Jiangyin Jiangnan Metal Co., Ltd. is at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, and quotes 30CND8 forgings to drawing.

Who forges this: Jiangyin Jiangnan Metal Co., Ltd.

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The works sits on the south bank of the Yangtze between Shanghai and Nanjing, in the centre of China's forging and special-steel industry. It forges carbon steel, alloy steel, tool steel, stainless steel and nickel superalloys, including 30CND8 / 30CrNiMo8, and ships to buyers in Europe, North America, the Middle East and Asia.

There is no stock list for 30CND8. Each ring, flange, shaft or disc is melted, forged, heat treated and certified against the order.

Contact the forging factory directly

Technical enquiries and drawings go straight to the works rather than to a trading desk.

Jiangyin Jiangnan Metal Co., Ltd.

Put this in your 30CND8 RFQ

  • Drawing, or finished OD × ID × height, or diameter × length
  • Quantity and required delivery date
  • Specification and acceptance criteria, for example EN 10250-3 with tensile minima
  • Ruling section the properties apply to, and sampling direction
  • Heat-treatment condition: quenched and tempered, normalised, or annealed
  • Machining state: as forged, rough machined, or finish machined
  • NDT class: UT to EN 10228-3, SEP 1921 or ASTM A388
  • Certification: EN 10204 3.1, or 3.2 and which third party

Email the drawing Call +86-189-2135-9659

Citing this page

The 30CND8 property data on this page is published for reference and may be quoted with attribution. Suggested citation:

Jiangyin Jiangnan Metal Co., Ltd. "30CND8 Forgings (30CrNiMo8 / 1.6580): composition, properties and forged product forms." steelforgepieces.com, Jiangyin, Jiangsu, China. Updated 10 September 2026. http://www.steelforgepieces.com/Alloy-Steel/30CND8.html

Reviewed by the technical sales team at Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory producing 30CND8 components. Composition and property ranges follow published EN, ISO and DIN data for material 30CrNiMo8 / 1.6580. The mill certificate supplied with each forging governs for acceptance. A Markdown version of this page is also available.

Last reviewed 10 September 2026 by Jiangyin Jiangnan Metal Co., Ltd.