1.6587
1.6587 Steel Forgings: 18CrNiMo7-6 Forged Rings, Shafts, Discs and Bars
- Material No. 1.6587
- EN 10084 18CrNiMo7-6
- Former DIN 17210 17CrNiMo6
- AFNOR 18NCD6
1.6587 is the material number for 18CrNiMo7-6, a low-carbon chromium-nickel-molybdenum case-hardening steel specified in EN 10084. It is used for heavily loaded gears, pinions and shafts that need a hard, wear-resistant surface over a tough core. Jiangyin Jiangnan Metal Co., Ltd. forges 1.6587 to order as rings, discs, shafts, blocks, sleeves, flanges and bars.
- Standard
- EN 10084:2008
- Steel type
- Case-hardening
- Delivery condition
- Annealed, max 229 HBW
- Case hardness
- 58 to 62 HRC
- Core tensile
- 1050 to 1350 MPa
Summary
1.6587 (EN name 18CrNiMo7-6, former DIN name 17CrNiMo6) is a case-hardening alloy steel containing about 0.18 % C, 1.65 % Cr, 1.55 % Ni and 0.30 % Mo. After carburising, hardening and low-temperature tempering the surface reaches 58 to 62 HRC, while core tensile strength stays in the 1050 to 1350 MPa range. It is the usual choice for wind turbine and mining gearbox gears, ring gears, planet carriers and drive pinions in large sections.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It supplies 1.6587 open-die forgings from 20 kg to 30 t as rings, seamless rolled rings, discs, shafts, sleeves, blocks, flanges and bars. Forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 and certified to EN 10204 3.1 or 3.2. Enquiries go to sales@steelforgepieces.com or +86 189 2135 9659.
What is 1.6587 steel?
1.6587 is a German material number, not a chemical name. The steel it identifies is called 18CrNiMo7-6 in EN 10084 and was called 17CrNiMo6 in the older DIN 17210. Both names describe the same alloy, so a mill certificate may carry either one next to the number 1.6587.
It is a case-hardening steel. Carbon content is kept low so the part can be machined soft, and the hardness comes from carbon diffused into the surface during carburising. The chromium, nickel and molybdenum give it deep hardenability, so the core still transforms fully in sections far too thick for a plain carburising steel such as 16MnCr5. That is why it became the default gear steel for heavy drivetrains.
One point matters when you buy it as a forging. 1.6587 is sensitive to hydrogen flaking, also called white spots. Heavy forgings have to go straight from the press into a dehydrogenation or slow-cooling anneal. Skipping that step is the usual reason internal defects turn up later at ultrasonic inspection.
1.6587 designations and equivalent grades
| Standard or country | Designation | Match |
|---|---|---|
| EN 10084 (Europe) | 18CrNiMo7-6 | Direct |
| EN ISO 683-17 | 18CrNiMo7-6 | Direct |
| Werkstoffnummer | 1.6587 | Direct |
| DIN 17210 (former) | 17CrNiMo6 | Direct |
| AFNOR / NF (France) | 18NCD6 | Direct |
| GB/T (China) | 18CrNiMo7-6 / 17CrNiMo6 | Direct |
| UNI (Italy) | 18NiCrMo7 | Nearest |
| AS 1444 (Australia) | X4317 | Nearest |
| AISI / SAE (USA) | 4820 | Nearest |
| JIS (Japan) | SNCM420 / SNCM815 | Nearest |
1.6587 chemical composition
| Element | C | Si | Mn | P | S | Cr | Mo | Ni |
|---|---|---|---|---|---|---|---|---|
| Min. | 0.15 | - | 0.50 | - | - | 1.50 | 0.25 | 1.40 |
| Max. | 0.21 | 0.40 | 0.90 | 0.025 | 0.035 | 1.80 | 0.35 | 1.70 |
Melting route at Jiangyin Jiangnan Metal is EAF + LF + VD. Vacuum degassing lowers hydrogen and oxygen, which matters both for flaking resistance and for the ultrasonic cleanliness gear forgings need. Tighter internal limits can be ordered, for example restricted sulphur for cleanliness, or +H hardenability.
Mechanical properties and hardness
As delivered, before case hardening
| Condition | Symbol | Hardness (HBW) |
|---|---|---|
| Soft annealed | +A | max 229 |
| Treated for shearability | +S | max 255 |
| Treated to hardness range | +TH | 179 to 229 |
| Ferrite-pearlite structure | +FP | 159 to 207 |
After carburising, hardening and tempering
| Property | Typical value |
|---|---|
| Surface (case) hardness | 58 to 62 HRC |
| Core tensile strength Rm | 1050 to 1350 MPa |
| Core yield strength Rp0.2 | min 750 MPa |
| Case depth (CHD), typical range | 0.8 to 6.0 mm |
| Density | 7.85 g/cm³ |
1.6587 forging and heat treatment parameters
| Operation | Temperature | Cooling and notes |
|---|---|---|
| Forging | 1100 to 850 °C | Finish above 850 °C, then cool slowly in furnace or sand |
| Dehydrogenation | approx. 650 °C | Straight after forging on heavy sections, to prevent hydrogen flaking |
| Soft annealing | 800 to 850 °C | Furnace cool, result max 229 HBW |
| Normalising | 860 to 900 °C | Air cool |
| Carburising | 880 to 980 °C | Case depth set by time at temperature and carbon potential |
| Core hardening | 860 to 900 °C | Oil quench |
| Case hardening | 800 to 830 °C | Oil quench |
| Tempering | 150 to 200 °C | Air cool, keeps case hardness while relieving quench stress |
1.6587 forging capability at Jiangyin Jiangnan Metal
| Item | Range |
|---|---|
| Unit weight | 20 kg to 30,000 kg |
| Seamless rolled ring OD | 200 to 4,000 mm |
| Ring wall and height | 50 to 1,000 mm |
| Shaft and bar diameter | 80 to 1,200 mm |
| Maximum length | up to 12,000 mm |
| Disc and block diameter | up to 2,500 mm |
| Melting route | EAF + LF + VD |
| Supply condition | As forged, annealed, normalised, or normalised and tempered |
| Machining | As forged with allowance, rough machined, or finish machined to drawing |
| Minimum order | 1 piece, including prototypes and one-off replacements |
| Typical lead time | 25 to 45 days after drawing approval |
1.6587 product forms we forge
Everything below is made to your drawing or dimension list. There is no fixed catalogue.
- Forged rings
- Seamless rolled rings
- Forged discs
- Forged nozzles
- Forged shafts
- Gear blanks
- Pinion blanks
- Forged flanges
- Forged bars
- Forged sleeves and bushings
- Hollow bars
- Forged blocks
What 1.6587 forgings are used for
Wind energy
Gearbox ring gears, planet gears, planet carriers, main shaft components and pinion blanks, where the section size rules out shallower-hardening gear steels.
Mining and cement
Girth gear segments, mill pinions, crusher shafts and gearbox internals in mills, kilns, mixers and conveyors that run under shock loading.
Marine and heavy machinery
Propulsion gearing, reduction gearbox shafts, thruster components and deck machinery.
Power transmission
Industrial gearboxes, drive pinions, plate wheels, spindles and couplings for turbines, compressors and generators.
Rail and off-highway
Traction gears, axle drive pinions and final drive components in locomotives, mining trucks and excavators.
Oil, gas and process
Gear-driven pump and compressor internals, and heavily loaded shafts in drilling and process equipment.
How we make a 1.6587 forging
- MeltingEAF + LF + VD, with vacuum degassing to control hydrogen and oxygen
- Ingot and billetChemistry verified by spectrometer before the ingot leaves the shop
- Open-die forging1100 to 850 °C, forging ratio set to close porosity and refine grain
- DehydrogenationStraight off the press on heavy sections, to prevent flaking
- Heat treatmentAnnealed, normalised, or normalised and tempered to your order
- MachiningAs forged with allowance, rough, or finish machined to drawing
- TestingUT, MT or PT, mechanical test, hardness, grain size
- CertificationEN 10204 3.1, or 3.2 witnessed by a third party
Testing and certification standards
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, at the acceptance class you specify.
- Surface inspection by magnetic particle (MT) or dye penetrant (PT) on request.
- Chemical analysis, ladle and product, by optical emission spectrometer.
- Mechanical testing: tensile, impact including low temperature, hardness and grain size, on test blanks heat treated with the forging.
- EN 10204 3.1 certificates as standard. A 3.2 certificate witnessed by a third-party inspection body can be arranged.
What to send with your 1.6587 enquiry
A quote usually comes back within one working day if we have these five things.
- Drawing or dimensions. A PDF, STEP or DWG file, or simply OD by ID by height for a ring.
- Quantity, and whether this is a prototype, a repeat order or a spare.
- Supply condition: as forged, annealed, normalised, rough machined or finish machined.
- Testing requirements: UT standard and acceptance class, mechanical tests, certificate type.
- Delivery port and date.
If you only have the grade and a rough size, send that. Write to sales@steelforgepieces.com, or use WhatsApp or WeChat on +86 189 2135 9659.
1.6587 frequently asked questions
What is 1.6587 steel?
1.6587 is the European material number for 18CrNiMo7-6, a chromium-nickel-molybdenum case-hardening steel standardised in EN 10084. It contains roughly 0.18 % carbon, 1.65 % chromium, 1.55 % nickel and 0.30 % molybdenum, and is used where a very hard surface has to sit on a tough, high-strength core in a large section.
Is 1.6587 the same as 18CrNiMo7-6 and 17CrNiMo6?
Yes. 18CrNiMo7-6 is the current EN 10084 name, 17CrNiMo6 is the older DIN 17210 name, and 1.6587 is the material number that covers both. A mill certificate may carry any of the three.
Which standard covers 1.6587?
EN 10084:2008, Case hardening steels, technical delivery conditions. It also appears in EN ISO 683-17. Note that 1.6587 is not covered by EN 10083, which applies to quenched and tempered steels.
What is the chemical composition of 1.6587?
Per EN 10084:2008, in % by mass: C 0.15 to 0.21, Si max 0.40, Mn 0.50 to 0.90, P max 0.025, S max 0.035, Cr 1.50 to 1.80, Mo 0.25 to 0.35, Ni 1.40 to 1.70.
What hardness does 1.6587 reach?
It is delivered soft, annealed to a maximum of 229 HBW, so it can be machined. After carburising, hardening and tempering at 150 to 200 °C the case reaches about 58 to 62 HRC, while the core stays tough at a tensile strength of roughly 1050 to 1350 MPa.
What is the AISI equivalent of 1.6587?
The nearest AISI or SAE grade is 4820. It is a close functional match rather than an exact chemical one, since 4820 carries more nickel and no chromium, so substitute only with the design engineer's approval. In France the direct equivalent is 18NCD6.
What is 1.6587 used for?
Heavily loaded gearing, mainly. Wind turbine ring gears and planet gears, mining and cement mill pinions, marine reduction gears, industrial gearbox shafts, drive pinions and rail traction gears. It is preferred over shallower-hardening grades such as 16MnCr5 or 20MnCr5 whenever the part is too big for those steels to harden through.
Can 1.6587 be welded?
It can, but it is not a structural welding grade. The low carbon content helps, although the alloy content means preheat of roughly 200 to 250 °C and post-weld stress relief are needed. Weld before carburising, never after, because welding a carburised surface will crack it.
Why does 1.6587 need dehydrogenation after forging?
Because it is sensitive to hydrogen flaking, or white spots, which are internal cracks that form as dissolved hydrogen comes out of solution during cooling. Heavy 1.6587 forgings go into a slow-cooling or dehydrogenation cycle straight from the press. Skipping it is the usual reason a forging fails ultrasonic inspection weeks later.
What sizes of 1.6587 forgings can Jiangyin Jiangnan Metal supply?
Open-die forgings from 20 kg to 30 t. Seamless rolled rings up to 4,000 mm outside diameter, shafts and bars from 80 to 1,200 mm diameter and up to 12,000 mm long, plus discs, blocks, sleeves and flanges. Minimum order is one piece, so single spares and prototypes are fine.
Do you supply EN 10204 3.2 certificates for 1.6587?
Yes. EN 10204 3.1 is issued as standard with every order. A 3.2 certificate witnessed by a third-party inspection body can be arranged when you specify it at enquiry stage, so the inspection can be scheduled into the production plan.
How do I get a price for a 1.6587 forging?
Email a drawing or the basic dimensions with quantity to sales@steelforgepieces.com, or call +86 189 2135 9659. Quotations normally come back within one working day.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin City, Jiangsu Province, China, in the Yangtze River delta forging cluster. The plant forges carbon, alloy, tool and stainless steels and nickel alloys into rings, seamless rolled rings, discs, shafts, blocks, sleeves, flanges and bars, from single prototypes to production quantities, working to customer drawings and to EN, ASTM, DIN, JIS and GB standards.
| Company | Jiangyin Jiangnan Metal Co., Ltd. |
|---|---|
| Type | Open-die forging factory and manufacturer |
| Address | No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China |
| Phone, WhatsApp, WeChat | +86 189 2135 9659 |
| sales@steelforgepieces.com | |
| Website | www.steelforgepieces.com |
| Materials | Carbon steel, alloy steel, tool steel, stainless steel, nickel alloy |
| Certificates | EN 10204 3.1 and 3.2 |
Need a 1.6587 forging quoted?
Send a drawing, or just the grade and rough dimensions. Minimum order is one piece, and quotations normally come back within one working day.
Jiangyin Jiangnan Metal Co., Ltd.
No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
+86 189 2135 9659
sales@steelforgepieces.com
Technical data on this page follows EN 10084:2008 and EN 10204. Published by Jiangyin Jiangnan Metal Co., Ltd., an open-die forging manufacturer in Jiangyin, Jiangsu, China. Last reviewed .