Jiangyin Jiangnan Metal Co., Ltd.
Forged rings · shafts · flanges · bars · discs
815M70
Enquiries for 815M70 resolve to 815M17, a case-hardening Ni-Cr-Mo alloy steel, open-die forged to your drawing.
815M70 is not a designation in BS 970. The last two digits of a BS 970 number give the mean carbon content, so 815M70 would describe a 0.70% carbon steel inside the nickel-chromium-molybdenum case-hardening series. That combination does not exist.
The grade being asked for is 815M17, the Ni-Cr-Mo case-hardening steel in BS 970-3:1991, equivalent to 17NiCrMo6-4 and Werkstoff 1.6566. Carburised, quenched and tempered it gives a case of 58–62 HRC over a core of 1000–1300 N/mm², which is why it is specified for gears, pinions, camshafts and heavy-section shafts. Jiangyin Jiangnan Metal Co., Ltd. forges 815M17 into rings, shafts, flanges, bars, discs and gear blanks at its factory in Jiangyin, Jiangsu, China.
Grade identification
- Enquiry as
- 815M70
- Supplied as
- 815M17
- Standard
- BS 970-3:1991
- Hardenability
- 815H17
- EN 10084
- 17NiCrMo6-4
- Werkstoff
- 1.6566
- France
- 18NCD6
- Italy
- 18NiCrMo5
- Steel type
- Case hardening
- Case hardness
- 58–62 HRC
- Melting
- EAF+VOD / ESR
- Certificate
- EN 10204 3.1 / 3.2
Chemical composition of 815M17
Composition limits are taken from BS 970 Part 3:1991. Every heat we forge is analysed on an optical emission spectrometer and the result is printed on the mill certificate.
| Element | Symbol | Minimum % | Maximum % |
|---|---|---|---|
| Carbon | C | 0.14 | 0.20 |
| Silicon | Si | 0.10 | 0.35 |
| Manganese | Mn | 0.60 | 0.90 |
| Chromium | Cr | 0.60 | 1.20 |
| Nickel | Ni | 1.20 | 1.70 |
| Molybdenum | Mo | 0.10 | 0.20 |
| Phosphorus | P | — | 0.030 |
| Sulphur | S | — | 0.030 |
| Iron | Fe | Balance | |
The nickel content is what separates 815M17 from leaner carburising steels such as 805M20 or 16MnCr5. It raises core hardenability, so a heavy gear blank still develops a strong core under the case. Tighter phosphorus and sulphur limits, or restricted residuals for gear duty, can be specified at enquiry stage.
815M17 equivalent grades
815M17 is the British designation. If your drawing calls out any of the grades below, we can forge it from the same material.
| Country or body | Standard | Designation |
|---|---|---|
| United Kingdom | BS 970-3:1991 | 815M17 / 815H17 |
| Europe | EN 10084 | 17NiCrMo6-4 |
| Germany | Werkstoff number | 1.6566 |
| France | NF A35-551 | 18NCD6 |
| Italy | UNI 8550 | 18NiCrMo5 |
| Sweden | SS 14 | SS 2523 |
| United States | ASTM A29 / SAE J404 | 4320 / 4820 nearest |
There is no exact AISI or SAE equivalent. AISI 4320 sits close on nickel and molybdenum but runs lower on chromium, and AISI 4820 carries roughly double the nickel. Where a US drawing calls for 4320 and a European drawing calls for 17NiCrMo6-4 on the same assembly, tell us before we melt, so the chemistry can be aimed at the overlap of both bands.
Mechanical properties of 815M17
Case-hardening steels are bought on core properties, because the surface is hardened as a separate operation. Core values fall as the ruling section grows, so tell us the section size that the property requirement applies to.
| Property | 11 mm section | 25 mm section | 40 mm section | 100 mm section |
|---|---|---|---|---|
| Tensile strength, MPa | 1225–1520 | 1030–1325 | 930–1230 | 785–1080 |
| Yield strength min, MPa | 980 | 785 | 735 | 590 |
| Elongation min, % | 8 | 9 | 9 | 10 |
| Impact KCU min, J | 30 | 32.5 | 32.5 | 35 |
Surface and delivery condition
- Case hardness after carburising, hardening and tempering: 58–62 HRC.
- Core tensile strength after case hardening: 1000–1300 N/mm².
- Soft annealed delivery hardness: 240 HBW maximum, so the part machines easily before heat treatment.
- Isothermal annealed hardness: 149–207 HBW, the condition we normally ship when the customer is hobbing gear teeth.
- Usual case depth range: 0.6–2.5 mm, set by carburising time and temperature.
- 815M17 does not respond well to flame or induction hardening, because the carbon content is too low. Nitriding is possible where carburising is not wanted.
Values are typical, for grade selection. The contractual figures are the ones recorded on the EN 10204 certificate for your heat and section, taken from a test prolongation representing the forging.
Forging and heat treatment of 815M17
This is the route we follow in our own shop. Steps 5 to 8 are normally carried out after machining, either by us or by your own heat treater. Critical points for this grade are Ac1 about 730 °C, Ac3 about 815 °C and Ms about 360 °C.
- ForgingHeat uniformly to
1100–1150 °C. Do not finish below900 °C. Forging reduction ratio4:1or better. - Dehydrogenation annealStart immediately after forging, while the piece is still hot. 815M17 is flake sensitive and this step is not optional on heavy sections.
- NormalisingHeat to
850–900 °C, hold until uniform, cool in still air. Refines the forged grain structure. - AnnealingIsothermal at
850–900 °Cwith a two hour hold at 650 °C, or subcritical at650–700 °C, furnace cooled. Gives a machinable structure. - CarburisingGas, pack or vacuum carburise at
870–900 °C. Time at temperature sets the case depth. - Core refiningReheat to
840–870 °Cand quench in oil, polymer or salt. Restores core toughness after the long carburising soak. - Case hardeningReheat to
800–830 °Cand quench to harden the carburised case. - TemperingTemper at
150–200 °Cand air cool. Relieves quenching stress while holding58–62 HRCat the surface.
Finishing a forging below 900 °C works a part-cooled billet and leaves coarse grain in the heaviest section, which shows up later as scattered ultrasonic noise and uneven case depth. We hold finish temperature by pyrometer on every heat. The temperatures above are a starting point for typical sections; confirm the cycle against your own qualified procedure before production.
815M17 forged products we make
Everything below is open-die forged or ring rolled to your drawing, not cut from stock plate or bar. Parts can leave the factory as forged, rough machined or finish machined.
Seamless rolled rings
Ring rolled for continuous circumferential grain flow, which is why forged rings out-perform cut rings in gear and bearing duty.
OD 200–4000 mm · height to 1000 mmForged rings and sleeves
Upset and mandrel-forged rings, bushings, sleeves and hollow bars for short runs where ring rolling is not economic.
OD 150–2500 mm · wall from 30 mmForged shafts
Straight, stepped, flanged and eccentric shafts, spindles, camshaft blanks and pinion shaft blanks drawn out for longitudinal grain flow.
Ø 80–1200 mm · length to 12 mForged round bars
Forged bar in the as-forged, normalised or annealed condition, cut to the lengths you need for gear and pinion machining.
Ø 80–1200 mmForged flanges
Weld neck, slip-on, blind and special profile flanges, plus forged tube sheets for heat exchangers.
OD to 3000 mmForged discs and blocks
Discs, disks, plates, blocks and rectangular forgings, including gear blanks and pinion blanks ready for hobbing.
Ø to 3000 mm · single piece to 60 tNot listed here? Send the drawing. Most of what we ship is a one-off or a small batch made to a customer print.
Where 815M17 forgings are used
815M17 is chosen when a component has to resist surface wear and contact fatigue at a section size where a leaner carburising steel would leave the core too soft.
| Industry | Typical parts | Reason for the grade |
|---|---|---|
| Gearboxes and power transmission | Ring gears, pinions, planet carriers, shafts | Hard case resists pitting, nickel keeps the core tough |
| Wind energy | Planetary gear blanks, rolled ring gear blanks | Core hardenability holds up in heavy sections |
| Heavy vehicles and off-highway | Camshafts, differential gears, piston pins | Contact fatigue life under shock loading |
| Marine propulsion | Reduction gear components, spindles | Toughness retained at large diameters |
| Mining and cement | Kiln drive pinions, mill gear segments | Abrasion resistance on the working face |
| General machine building | Bushings, sleeves, splined shafts, rollers | Machines soft, hard where it runs |
815M17 is a carburising steel, not a pressure-vessel grade. For valve bodies, bonnets, stems and pressure flanges, specify a through-hardening grade such as AISI 4140, 42CrMo4, 817M40 or AISI 8630. We forge all of those from the same shop.
Testing, inspection and certification
Tell us the acceptance standard at enquiry stage and it goes on the works order, rather than onto a certificate written afterwards.
- Chemical analysis: optical emission spectrometry on every heat, reported against BS 970-3:1991, EN 10084 or the standard you specify.
- Mechanical testing: tensile, yield, elongation, reduction of area, Charpy V-notch impact, and Brinell or Rockwell hardness, taken from a test prolongation representing the forging.
- Ultrasonic testing: to EN 10228-3, SEP 1921 or ASTM A388, to the quality class you nominate.
- Jominy end-quench: to ISO 642 or ASTM A255 for 815H17 hardenability orders, with the band plotted on the certificate.
- Surface crack detection: magnetic particle inspection to ASTM E709, or dye penetrant inspection to ASTM E165.
- Grain size and microstructure: austenitic grain size to ASTM E112, with micrographs on request.
- Dimensional inspection: full dimensional report against your drawing before packing.
- Certification: EN 10204 3.1 as standard, or EN 10204 3.2 witnessed by TUV, SGS, BV, Lloyd's Register or DNV at your cost.
Buying 815M17 forgings from Jiangyin Jiangnan Metal
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. We forge 815M17 and around two hundred other grades of carbon steel, alloy steel, tool steel, stainless steel and nickel alloy, and we export to Europe, North America, the Middle East and South-East Asia.
Made to drawing, not to catalogue
We are a forging shop, not a stockist. Send a print or the finished sizes and we forge to it, including one-offs and replacement parts with no original drawing.
Quotation within 24 hours
A written price, forged weight, lead time and machining allowance normally comes back the next working day. Drawings are treated as confidential.
Traceable material
The heat number is stamped on the forging and carried through to the EN 10204 certificate, so the part can be traced back to the melt years later.
Machining in house
Turning, boring, milling and drilling, so you can buy the part rough machined to a defined allowance instead of as a raw forging.
Melting route you can specify
EAF with VOD as standard, or electroslag remelted 815M17 where the cleanliness requirement is severe. State the route on your enquiry.
Third-party witness welcome
We work to EN 10204 3.2 with TUV, SGS, BV, Lloyd's Register or DNV attending the tests when your specification calls for it.
815M70 and 815M17 questions we get asked
Short answers to the things buyers and design engineers ask before placing an order against this grade.
Is 815M70 a real steel grade?
815M70 does not appear in BS 970. In the BS 970 designation system the last two digits give the mean carbon content, so 815M70 would describe a 0.70% carbon steel inside the nickel-chromium-molybdenum case-hardening series, which does not exist. Enquiries for 815M70 are almost always for 815M17, the Ni-Cr-Mo case-hardening steel in BS 970-3:1991. If your drawing genuinely calls for 0.70% carbon material, send it over and we will identify the grade from the chemistry before quoting.
What is 815M17 steel?
815M17 is a nickel-chromium-molybdenum case-hardening (carburising) alloy steel specified in BS 970-3:1991. It contains 0.14–0.20% carbon, 0.60–1.20% chromium, 1.20–1.70% nickel and 0.10–0.20% molybdenum. Carburised, quenched and tempered it gives a case of 58–62 HRC over a core with a tensile strength of 1000–1300 N/mm², which is why it is used for gears, pinions, camshafts and heavy-section shafts.
What is the equivalent of 815M17?
815M17 is equivalent to 17NiCrMo6-4 and Werkstoff 1.6566 under EN 10084, 18NCD6 in France, 18NiCrMo5 under UNI 8550 in Italy and SS 2523 in Sweden. There is no exact AISI or SAE equivalent: AISI 4320 is the nearest on nickel and molybdenum but carries less chromium, and AISI 4820 carries roughly double the nickel. Composition limits differ between standards, so confirm which standard the certificate should be issued against.
What is the chemical composition of 815M17?
Per BS 970-3:1991, 815M17 contains carbon 0.14–0.20%, silicon 0.10–0.35%, manganese 0.60–0.90%, chromium 0.60–1.20%, nickel 1.20–1.70% and molybdenum 0.10–0.20%, with phosphorus and sulphur each 0.030% maximum. The balance is iron.
What is the difference between 815M17 and 815H17?
The chemistry band is the same. 815M17 is ordered to mechanical properties, while 815H17 is ordered to a hardenability band verified by a Jominy end-quench test. Specify 815H17 when case depth and core hardness have to repeat across a batch of gears, and 815M17 when a tensile figure on the certificate is what the drawing calls for.
Why does 815M17 need annealing straight after forging?
815M17 is a low-carbon Cr-Ni-Mo steel and is sensitive to hydrogen flaking. Dissolved hydrogen comes out of solution as a heavy forging cools and opens internal cracks that are found later at ultrasonic inspection, or in service. A dehydrogenation anneal started immediately after forging, while the piece is still hot, lets the hydrogen diffuse out before the section cools through the critical range.
What forged shapes can be produced in 815M17?
Jiangyin Jiangnan Metal Co., Ltd. produces 815M17 as seamless rolled rings, forged rings, round bars, shafts, stepped and eccentric shafts, flanges, discs and disks, gear and pinion blanks, sleeves, bushings, hollow bars and blocks. All parts are open-die forged to customer drawing and can be supplied rough machined or finish machined.
Can 815M17 be used for valve bodies or pressure parts?
815M17 is a carburising steel, built to be hard at the surface and tough in the core, and it is not a pressure-vessel grade. For valve bodies, bonnets, stems and pressure flanges use a through-hardening grade such as AISI 4140, 42CrMo4, 817M40 or AISI 8630. We forge all of those from the same shop.
Who supplies 815M17 open-die forgings?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China that manufactures and exports 815M17 forgings worldwide. Material is melted by EAF plus VOD or by ESR, forged to BS 970-3:1991, and supplied with EN 10204 3.1 or 3.2 certification.
Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.
What inspection and certification comes with the forgings?
815M17 forgings are supplied with chemical analysis, tensile, impact and hardness results, and ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 as specified on the order. Magnetic particle and dye penetrant inspection are available, as is a Jominy end-quench report for 815H17 orders. Certificates are issued to EN 10204 3.1, or 3.2 witnessed by a third party such as TUV, SGS, BV, Lloyd's Register or DNV.
What do you need in order to quote?
Send a drawing or the finished dimensions, the quantity, the delivery condition (as forged, normalised, annealed, or hardened and tempered), the machining allowance, the required ultrasonic testing standard and the certificate type. A written quotation normally comes back within 24 hours.
Send us the drawing for your 815M17 part
Email the print, or just the finished sizes and quantity, and you will have a price, a forged weight and a lead time back within one working day. If there is no drawing, a photograph and a few measurements are usually enough to start.
- Works
- No.1 Chengxiqiao Road, Zhouzhuang Town,
Jiangyin City, Jiangsu Province 214423, China - Phone
- +86 189 2135 9659
- sales@steelforgepieces.com
- Web
- steelforgepieces.com