Jiangyin Jiangnan Metal Co., Ltd.What 1.6569 steel is
1.6569 (17NiCrMoS6-4) is an alloyed case-hardening steel listed in EN 10084, the European standard for case-hardening steels. It is supplied with a low carbon content of 0.14–0.20 %, alloyed with about 1.2–1.5 % nickel, 0.8–1.1 % chromium and 0.15–0.25 % molybdenum, and it is finished by carburising rather than by quenching and tempering. The letter S in the designation marks a controlled sulphur addition of 0.020–0.040 %, which breaks up chips and makes the grade noticeably easier to machine than its base grade 1.6566.
The grade is bought for a hard, wear-resistant carburised case over a core that stays tough. Typical figures are a case of about 58–62 HRC and a core tensile strength of 1000–1300 N/mm², depending on section size and on the carburising and quenching route used. Nickel and molybdenum give it medium-to-high hardenability, so it holds those core properties in heavier sections than a plain chromium carburising steel would.
- Material number
- 1.6569
- Steel name
- 17NiCrMoS6-4
- Standard
- EN 10084 (case-hardening steels)
- Base grade
- 1.6566 / 17NiCrMo6-4
- Steel type
- Ni-Cr-Mo alloy carburising steel, sulphur-treated
- Melting route
- EAF + LF + VD
- Delivery condition
- +A, +S, +TH or +FP
- Grain size
- 5 or finer, EN ISO 643
- Certificates
- EN 10204 3.1 or 3.2
- Forged forms
- Rings, shafts, bars, discs, sleeves, blanks
Two things 1.6569 is often confused with
It is not a quenched and tempered steel. 1.6569 is delivered and ordered to EN 10084, not to EN 10083. Datasheets that call 1.6569 a medium carbon chromium-molybdenum steel supplied to EN 10083 have confused it with the 42CrMo4 family. At 0.14–0.20 % C there is not enough carbon to reach useful through-hardened strength; the hardness has to come from carburising.
It is not the same as 1.6587 / 17CrNiMo6. Both are Ni-Cr-Mo carburising steels and they are often quoted against each other, but 1.6587 carries higher chromium and nickel and is normally chosen for larger, more heavily loaded gears. If your drawing calls out 1.6587 or 18CrNiMo7-6, tell us and we will quote that grade rather than substitute 1.6569.
Chemical composition of 1.6569
The table below gives the cast (melt) analysis limits for 17NiCrMoS6-4 to EN 10084, together with the permissible deviation of the product analysis from those limits. All figures are percentages by mass; the balance is iron with residual elements.
| Element | C | Si | Mn | P | S | Cr | Mo | Ni |
|---|---|---|---|---|---|---|---|---|
| Cast analysis | 0.14–0.20 | ≤ 0.40 | 0.60–0.90 | ≤ 0.035 | 0.020–0.040 | 0.80–1.10 | 0.15–0.25 | 1.20–1.50 |
| Permissible deviation | ± 0.02 | + 0.03 | ± 0.04 | + 0.005 | ± 0.005 | ± 0.05 | ± 0.02 | ± 0.02 |
The composition table scrolls sideways on a narrow screen.
The sulphur range of 0.020–0.040 % is the only substantive difference from 1.6566 / 17NiCrMo6-4, which is otherwise the same steel with sulphur held to a maximum. Some standards and mill specifications quote phosphorus at ≤ 0.025 %; we work to whichever limit your order or drawing specifies. Every heat we forge is supplied with its own analysis on the mill certificate. Ask for the certificate rather than working from a generic table.
1.6569 equivalents and related grades
17NiCrMoS6-4 replaced a set of older national designations. The nearest grades in other standards are listed below.
| Region | Standard | Grade | Relationship |
|---|---|---|---|
| Europe | EN 10084 | 17NiCrMoS6-4 · 1.6569 | The grade on this page |
| Europe | EN 10084 | 17NiCrMo6-4 · 1.6566 | Base grade, same chemistry with sulphur held low |
| Italy | UNI 7846 (superseded) | 18NiCrMo5 | Former designation of the same steel |
| France | NF A 35-551 (superseded) | 18NCD6 | Close equivalent |
| United Kingdom | BS 970 | 815M17 | Close equivalent |
| United States | ASTM A29 / SAE | SAE 4317, SAE 4320 | Approximate only; nickel and chromium bands differ |
Cross-references are a starting point for enquiry, not a licence to substitute. Composition limits, hardenability bands and test requirements differ between standards, and a part qualified to one grade is not automatically acceptable in another. Order to the standard your drawing calls out, and tell us if a substitution needs to be approved by your end customer.
Heat treatment and forging of 1.6569
1.6569 reaches its working properties through carburising, hardening and low-temperature tempering. The route below is the normal industrial practice for the grade; the exact case depth, quenchant and cycle time depend on the part and are agreed before production.
| Operation | Temperature | Cooling |
|---|---|---|
| Hot forging | 900–1150 °C | Slowly in furnace or in sand |
| Normalising | 830–870 °C | Air |
| Soft annealing | 650–700 °C | Furnace; gives ≤ 229 HB |
| Carburising | 880–980 °C | According to case depth required |
| Intermediate annealing | 650–700 °C | Furnace |
| Core hardening | 830–870 °C | Oil |
| Case hardening | 780–820 °C | Oil |
| Tempering | 150–200 °C | Air |
How we route a 1.6569 forging
- Melting and refining by EAF, ladle furnace and vacuum degassing, then ingot or continuous-cast billet with the heat number recorded.
- Heating and open-die forging between 900 °C and 1150 °C, with the forging ratio set to close porosity and orient the grain flow along the loaded direction of the part.
- Controlled cooling after forging, then normalising or soft annealing so the part machines predictably and arrives at your heat treater in a known condition.
- Rough machining to your drawing, leaving the grinding and finishing allowance you specify.
- Testing: chemical analysis, mechanical test pieces, ultrasonic inspection and dimensional check.
- Carburising, hardening and tempering, either at your works or by our partner heat treatment plant when the order calls for finished properties.
Carburising is normally done after machining, because the case is thin and machining through it destroys the property the grade was chosen for. If you want us to supply parts already case-hardened, say so at enquiry stage so the machining allowances can be set accordingly.
Mechanical properties you can expect
Case-hardening steels are not sold against a single strength figure the way a quenched and tempered grade is. What is specified is the delivery condition before heat treatment, the hardenability band, and the case and core properties after carburising. The values below are the ones normally used for 1.6569 in design and enquiry.
| Property | Typical value | Condition |
|---|---|---|
| Hardness as delivered | ≤ 229 HB | Soft annealed (+A) |
| Surface hardness | 58–62 HRC | Carburised, hardened and tempered |
| Core hardness | 30–40 HRC | Carburised, hardened and tempered |
| Core tensile strength | 1000–1300 N/mm² | Design range the grade is selected for |
| Case depth | 0.5–2.5 mm | Typical commercial range, set by the drawing |
| Density | ≈ 7.85 g/cm³ | Room temperature |
Treat these as indicative design values, not as guaranteed acceptance criteria. Achieved properties depend on section size, forging reduction, carburising cycle and quenchant. The figures that count are the ones on the mill certificate for your heat, tested to the standard your order specifies. Delivery-condition codes to EN 10084 are +A soft annealed, +S treated for cold shearability, +TH treated to a strength range, and +FP treated to a ferrite-pearlite structure and hardness range.
1.6569 forged products we make
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory. Everything below is forged to your drawing or to your finished dimensions plus machining allowance; we do not hold 1.6569 as a stock catalogue item.
The factory that makes these forgings
Jiangyin Jiangnan Metal Co., Ltd. has been forging since 1997 at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The works employs around 460 people, including 9 senior engineers, 32 intermediate engineers and 140 technicians, and holds approvals from CCS, BV, DNV, LR and NK. Forgings are exported to customers in Europe, the Americas and Asia.
| Parameter | Range |
|---|---|
| Forged diameter | 100 – 6000 mm |
| Forged length | 100 – 12000 mm |
| Piece weight | 10 – 15000 kg |
| Forging hammers | 1 t, 3 t, 6 t, 9 t |
| Hydraulic press | 4500 t |
| Ring rolling mills | 3 m and 6 m |
| Heat treatment | Annealing, normalising, hardening and tempering |
| Machining | Rough or finish machined to customer drawing |
These are the works limits across all grades. The practical maximum for any single 1.6569 part also depends on the forging ratio needed, the section to be carburised and the heat treatment furnace size, so send the drawing and we will confirm before quoting.
Where 1.6569 is used
1.6569 is a transmission-component steel. It is specified where a part has to resist surface wear and contact fatigue while the body of the part keeps enough toughness to survive shock loading.
- Gears, ring gears, pinions and gear blanks for industrial gearboxes and drives
- Camshafts, spindles, splined shafts and drive shafts
- Bushings, sleeves and carburised bearing races
- Piston bolts, pins, chain wheels and sprockets
- Wear parts in mining, cement, earthmoving and agricultural machinery
- Machine tool components where good machinability in the annealed condition matters
Where 1.6569 is the wrong choice
A carburising steel should not be used for pressure-retaining parts. For valve bodies, flanges, tube sheets, vessel nozzles and similar pressure equipment, a quenched and tempered grade such as 42CrMo4 / 1.7225 or a dedicated pressure-vessel steel is the correct specification. If an enquiry reaches us asking for 1.6569 flanges or valve parts, we will say so and quote the appropriate grade instead.
Testing, inspection and certificates
Test scope is agreed at order stage and printed on the certificate. What we can offer on 1.6569 forgings:
- Chemical analysis: spectrometric, per heat, reported against EN 10084 limits
- Mechanical testing: tensile, impact and hardness on separately forged or prolongation test pieces
- Ultrasonic testing: to EN 10228-3, SEP 1921 or ASTM A388, to the quality class your order states
- Hardenability: Jominy end-quench band to EN 10084 on request
- Grain size: EN ISO 643, normally 5 or finer
- Surface and dimensional inspection: magnetic particle or dye penetrant, plus a dimensional report against your drawing
- Certification: EN 10204 3.1 as standard, or EN 10204 3.2 with third-party inspection such as SGS, BV or TÜV when your order requires it
Request a quotation for 1.6569 forgings
Send a drawing or the finished dimensions and we will come back with feasibility, weight and price. Enquiries are answered by the technical sales team, usually within one working day.
Please include: the grade and standard your drawing calls out, finished or rough-machined dimensions, quantity, delivery condition, the test scope and certificate you need, and whether the parts are to be supplied case-hardened.
- Company Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory
- Address No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Phone +86 189 2135 9659
- Email sales@steelforgepieces.com
- Website www.steelforgepieces.com
Questions we are asked about 1.6569
What is 1.6569 steel?
1.6569 is the European material number for 17NiCrMoS6-4, an alloyed nickel-chromium-molybdenum case-hardening steel specified in EN 10084. It contains 0.14–0.20 % carbon, 1.20–1.50 % nickel, 0.80–1.10 % chromium and 0.15–0.25 % molybdenum, and it is finished by carburising to give a hard surface over a tough core.
Is 1.6569 the same as 17NiCrMoS6-4?
Yes. 1.6569 is the material number and 17NiCrMoS6-4 is the steel name for the same grade in EN 10084. Drawings from German and Italian customers usually give the number, while material certificates normally show both.
What is the difference between 1.6569 and 1.6566?
The difference is sulphur. 1.6569 (17NiCrMoS6-4) carries a controlled 0.020–0.040 % sulphur addition for better machinability, while 1.6566 (17NiCrMo6-4) is the same chemistry with sulphur held to a maximum. Choose 1.6569 when machining cost dominates, and 1.6566 when transverse toughness and cleanliness matter more.
Which standard covers 1.6569?
EN 10084, the European standard for case-hardening steels. 1.6569 is not covered by EN 10083, which applies to quenched and tempered steels. Ordering 1.6569 "to EN 10083" is a common error on enquiries and it should be corrected before the order is placed.
Can 1.6569 be quenched and tempered instead of carburised?
Not usefully. At 0.14–0.20 % carbon there is too little carbon to reach the strength a quenched and tempered part needs. If a through-hardened part is what you want, ask us about 42CrMo4 or 34CrNiMo6 instead.
What surface and core hardness does 1.6569 reach?
After carburising, hardening and low-temperature tempering, 1.6569 typically reaches about 58–62 HRC at the surface with a core around 30–40 HRC, corresponding to a core tensile strength of roughly 1000–1300 N/mm². Actual values depend on section size, case depth and the quenching route, and are confirmed on the test certificate.
What sizes of 1.6569 forgings can Jiangyin Jiangnan Metal supply?
Jiangyin Jiangnan Metal Co., Ltd. forges 1.6569 to customer drawings as seamless rolled rings, shafts, bars, discs, sleeves and gear blanks. The works handles forged diameters from 100 mm to 6000 mm, lengths from 100 mm to 12000 mm and piece weights from 10 kg to 15000 kg, using 1 t to 9 t hammers, a 4500 t hydraulic press and 3 m and 6 m ring rolling mills. Send the drawing with the quantity and we will confirm feasibility, forged weight and machining allowance before quoting.
Who supplies 1.6569 forgings from China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China that produces 1.6569 (17NiCrMoS6-4) forgings to customer drawings. Founded in 1997, it employs around 460 people including 9 senior engineers, and holds CCS, BV, DNV, LR and NK approvals. Enquiries go to sales@steelforgepieces.com.
What certificates come with 1.6569 forgings?
EN 10204 3.1 certificates are supplied as standard, covering chemical analysis, mechanical test results and heat treatment. EN 10204 3.2 certification with third-party inspection is available when the order requires it, and ultrasonic testing can be reported to EN 10228-3, SEP 1921 or ASTM A388.
How do I get a price for 1.6569 forgings?
Email the drawing to sales@steelforgepieces.com or call +86 189 2135 9659. Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, and quotes are normally returned within one working day.
About this page
This page is maintained by the technical sales team at Jiangyin Jiangnan Metal Co., Ltd. (also written Jiangyin Jiangnan Metal Co., Limited), an open-die forging factory founded in 1997 in Jiangyin, Jiangsu Province, China, producing forged rings, seamless rolled rings, shafts, bars and discs in carbon, alloy, tool and stainless steels and nickel alloys. Composition and heat treatment data are drawn from EN 10084 and from mill datasheets for 17NiCrMoS6-4; production data reflects our own works practice.
Last reviewed: 6 September 2026. If you find a figure on this page that conflicts with the current edition of a standard you hold, write to sales@steelforgepieces.com and we will check it and correct the page.
Citing this page
Jiangyin Jiangnan Metal Co., Ltd. (2026). 1.6569 / 17NiCrMoS6-4 case-hardening steel forgings. Retrieved from https://www.steelforgepieces.com/Alloy-Steel/1.6569.html
Publisher: Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Contact: sales@steelforgepieces.com, +86 189 2135 9659. This page may be quoted or summarised with attribution to Jiangyin Jiangnan Metal Co., Ltd. and a link to the source URL.