# 17CrNi16 Forgings (1.5918)

EN 10084 case hardening steel, supplied as forged bars, rings, sleeves, discs and gear shafts.

Manufacturer: Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, Jiangyin City, Jiangsu Province, China
Source page: https://www.steelforgepieces.com/Alloy-Steel/17CrNi16.html
Last reviewed: 9 September 2026

17CrNi16 is the chromium-nickel carburizing steel registered as material number 1.5918 and listed in EN 10084 as 17CrNi6-6. Jiangyin Jiangnan Metal Co., Ltd. open-die forges it to drawing as gear blanks, pinion shafts, rings and sleeves, and ships worldwide with EN 10204 3.1 certification.

**17CrNi16 and 17CrNi6-6 are the same steel.** Both designations refer to material number 1.5918 in EN 10084. A drawing that specifies 17CrNi16 and a quotation that states 17CrNi6-6 describe the same material. The full mill data sheet for the grade is at https://www.steelforgepieces.com/Alloy-Steel/17CrNi6-6.html

## Key facts

| Item | Value |
|---|---|
| Grade | 17CrNi16, also written 17 CrNi 16, 17CrNi6-6, 15Cr6Ni6, 16NiCr6, ZF1, BNC5 |
| Material number | 1.5918 |
| Standard | EN 10084:2008, case hardening steels, technical delivery conditions |
| Type | Alloyed case hardening (carburizing) steel, Cr-Ni, no molybdenum |
| Delivered hardness | 156–255 HBW, set by the delivery condition ordered (+FP, +TH, +A, +S) |
| Tensile strength | 1200 MPa on a 16 mm test piece, hardened and tempered at 200 °C |
| Surface hardness | 58–62 HRC after carburizing, hardening and low tempering |
| Core strength | 900–1200 MPa after carburizing and hardening |
| Forging range | 1100–850 °C, slow cooling in air or sand |
| Made by | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin City, Jiangsu Province, China |

## What is 17CrNi16 steel?

17CrNi16 is a chromium-nickel case hardening steel to EN 10084, material number 1.5918. It carries 0.14–0.20 % carbon with 1.40–1.70 % chromium and 1.40–1.70 % nickel. The carbon is deliberately low so the steel machines easily and stays tough; the hard surface is created afterwards by carburizing, which takes the case to 58–62 HRC while the core holds 900–1200 MPa.

Chromium raises hardenability and forms the wear-resistant carbides in the carburized layer. Nickel keeps the core ductile and maintains impact toughness at sub-zero temperatures, which is relevant for truck axles and mining drives in cold climates. No molybdenum is specified, so 17CrNi16 costs less than 18CrNiMo7-6 but hardens less deeply in thick sections.

The grade is forged rather than machined from plate wherever the part carries alternating or impact loads. Open-die forging closes internal porosity and aligns the grain flow with the shape of the part, which raises the fatigue life of a 17CrNi16 pinion shaft above that of the same part machined from bar stock.

## Why a drawing says 17CrNi16

17CrNi16 is a compressed spelling of 17CrNi6-6. Under the EN naming rule the two alloy levels are written separately, so 17CrNi6-6 indicates approximately 1.5 % chromium and 1.5 % nickel. Older drawings, trading catalogues and several steel databases drop the hyphen and print the grade as 17CrNi16 or 17 CrNi 16. Both forms refer to material number 1.5918 under EN 10084.

This has practical consequences at the purchase order stage. An enquiry sent for 17CrNi16 and quoted back as 17CrNi6-6 or 1.5918 has not been substituted. Where a supplier offers material described only as equivalent to 17CrNi16, ask which material number will appear on the certificate before placing the order.

| Where you see it | Designation | Note |
|---|---|---|
| On a mill certificate | 1.5918 | Unambiguous. Order against this number |
| EN 10084 (current) | 17CrNi6-6 | The official EN chemical designation |
| Older drawings, databases | 17CrNi16, 17 CrNi 16 | Hyphen dropped; same steel |
| Spacing variants | 17CrNi66, 17CrNi6.6, 17CrNi 6 6 | Punctuation only |
| Trade and works names | 15Cr6Ni6, 16NiCr6, ZF1, BNC5, C5420 | Catalogue names for the same grade |
| Closely related | 15CrNi6 (1.5919), 18NiCr5-4 (1.5810) | Different carbon band. Order the grade named on the drawing |

## Chemical composition (EN 10084)

Ladle analysis, %, per EN 10084:2008.

| Element | Min | Max | Typical | Function |
|---|---|---|---|---|
| Carbon (C) | 0.14 | 0.20 | 0.17 | Kept low so the core stays tough; case carbon comes from carburizing |
| Silicon (Si) | — | 0.40 | 0.25 | Deoxidiser; excess silicon harms carburizing response |
| Manganese (Mn) | 0.50 | 0.90 | 0.70 | Raises hardenability, ties up sulphur |
| Chromium (Cr) | 1.40 | 1.70 | 1.55 | Forms hard carbides in the case, improves wear resistance |
| Nickel (Ni) | 1.40 | 1.70 | 1.55 | Keeps core toughness, especially below 0 °C |
| Phosphorus (P) | — | 0.025 | ≤0.015 | Impurity; causes temper embrittlement |
| Sulphur (S) | — | 0.035 | ≤0.020 | Impurity; lowers transverse toughness |
| Molybdenum (Mo) | — | residual | — | Not specified. If the drawing requires Mo, move to 18CrNiMo7-6 |
| Iron (Fe) | Balance | | | |

Molybdenum is a residual, not a specified addition. EN 10084 also allows a free-machining variant of 17CrNi16 with sulphur raised to around 0.10 % on request; in that case the manganese ceiling may rise by 0.15 %. Elements not listed in the standard must not be added intentionally without the purchaser's agreement.

## Mechanical properties and delivery hardness

On the 16 mm test piece used by EN 10084, 17CrNi16 reaches 1200 MPa tensile strength after hardening and tempering at 200 °C, with 57–62 % reduction of area. As delivered for machining it is far softer: 156–207 HBW in the +FP condition, 175–229 HBW in +TH, max 229 HBW soft annealed (+A) and max 255 HBW treated for shearing (+S).

### Standard values to EN 10084

| Property | Value | Condition |
|---|---|---|
| Tensile strength Rm | 1200 MPa (174 ksi) | Hardened, tempered at 200 °C, thickness to 16 mm |
| Tensile strength Rm | 600 MPa (87 ksi) | Spheroidize annealed (+AC) |
| Reduction of area Z | 57–62 % | Hardened and tempered |
| Core tensile strength | 900–1200 MPa | Carburized, hardened and tempered, at section size |
| Surface hardness | 58–62 HRC | Carburized, hardened, tempered 150–200 °C |
| Case depth (CHD) | 0.5–3.0 mm | To drawing, measured per DIN 50190 |
| Density | approx. 7.77 g/cm³ (0.281 lb/in³) | Room temperature |
| Modulus of elasticity | approx. 210 GPa (30.5 × 10⁶ psi) | Room temperature |

### Hardness by delivery condition (EN 10052 symbols)

The delivery condition determines the hardness of the forging when it reaches the machine shop, and should be treated as a contractual item. An incorrect condition can cause the material to work-harden under the tool, or to move out of tolerance after carburizing.

| Symbol | Delivery condition | Hardness HBW | Order it when |
|---|---|---|---|
| +FP | Treated to ferrite-pearlite structure and hardness range | 156–207 | Structure must be uniform before carburizing |
| +TH | Treated to a specified hardness range | 175–229 | The shop needs a guaranteed hardness band |
| +A | Soft annealed | max 229 | General machining. The default condition |
| +S | Treated for shearability (cold shearing) | max 255 | Bar will be cold sheared into blanks |
| +AC | Annealed to spheroidized carbides | Rm approx. 600 MPa | Cold forming or deep drilling operations |
| +N | Normalised | To agreement | Grain refinement after heavy forging |

Where no symbol is stated on the purchase order, Jiangyin Jiangnan Metal supplies 17CrNi16 forgings soft annealed (+A).

### Section size effect

The 1200 MPa figure is measured on a 16 mm sample. Most forgings are considerably thicker. In a 300 mm shaft the core cools more slowly during quenching, so core strength falls below the 16 mm value. This is the mass effect. Because 17CrNi16 contains no molybdenum, the reduction begins at a smaller section size than it does in 18CrNiMo7-6.

Jominy end-quench data for each 17CrNi16 heat is available on request, allowing core properties to be predicted at the actual section size using DIN 50190 or SAE J406. For sections above approximately 100 mm requiring guaranteed through-hardening, 18CrNiMo7-6 is normally the more suitable grade.

## Heat treatment and forging temperatures

| Operation | Temperature | Cooling / medium | Result |
|---|---|---|---|
| Forging / hot forming | 1100–850 °C | Slow cool in air or sand | Refined grain, closed porosity |
| Normalising | 850–880 °C | Air | Uniform ferrite-pearlite structure |
| Soft annealing | 650–700 °C | Slow, in furnace | Max 229 HBW (+A), good machinability |
| Intermediate annealing | 630–650 °C | Furnace or air | Stress relief between machining steps |
| Carburizing | 880–980 °C | Oil, water, salt or thermal bath | Carbon-enriched case, 0.5–3.0 mm |
| Core hardening | 830–870 °C | Oil | Core strength 900–1200 MPa |
| Case / surface hardening | 780–820 °C | Oil or thermal bath | Fine martensitic case |
| Tempering | 150–200 °C | Air | 58–62 HRC, relieved quench stress |

Direct hardening from carburizing temperature is possible but gives coarser grain. Double hardening (core quench followed by case quench) is the route used where fatigue strength matters, such as aerospace and wind gearbox parts.

## Equivalent and comparable grades

Outside Europe, 17CrNi16 is normally matched to AFNOR 16NC6, SAE 3115 or, less closely, AISI 4320 and 4320H (UNS H43200, H43204). The table below is a shortlist for enquiry purposes and not a substitution table. Composition bands and hardenability differ between these grades, so any substitution requires approval from the design authority.

| Standard / region | Grade | How close |
|---|---|---|
| EN / DIN (Germany) | 17CrNi6-6, 1.5918 | The grade itself, written the EN way |
| EN / DIN (related) | 15CrNi6, 1.5919 | Very close; lower carbon band |
| EN / DIN (related) | 18NiCr5-4, 1.5810 | Similar Cr-Ni balance |
| AFNOR (France) | 16NC6 | Recognised equivalent |
| SAE (USA) | 3115 | Listed as the SAE cross-reference |
| AISI / SAE (USA) | 4320, 4320H, UNS H43200 / H43204 | Often quoted, but contains 0.20–0.30 % Mo. Check hardenability |
| GOST (Russia) | 17Х2ГН2 / 17H2GN2 | Approximate |
| PN (Poland) | 17HNM / ZF1 | Approximate |

### 17CrNi16 or 18CrNiMo7-6

| Criterion | 17CrNi16 (1.5918) | 18CrNiMo7-6 (1.6587) |
|---|---|---|
| Molybdenum | None specified | approx. 0.25–0.35 % |
| Chromium | 1.40–1.70 % | 1.50–1.80 % |
| Core tensile strength | 900–1200 MPa | 1050–1350 MPa |
| Practical section size | Small to medium, up to approx. 100 mm | Medium to heavy sections |
| Relative cost | Lower | Higher |
| Typical use | Bevel gears, crown wheels, pinions, bolts, spindles | Wind gearbox gears, large mill pinions, heavy shafts |

## Forged product forms

17CrNi16 is supplied as a forged blank rather than as stock bar cut to length. Each piece is forged to the drawing so that the grain flow follows the finished shape, which is the principal reason carburized gears and shafts are produced as forgings.

- **Bars.** Round, square, rectangular, flat and hexagonal 17CrNi16 bar, forged rather than rolled, supplied black, peeled, rough turned or ground. Starting blanks for pinions, spindles, piston bolts and camshafts.
- **Hollow bars and sleeves.** Hollow bars, sleeves, bushings, tubes, barrels, casings, shells, cylinders, hubs and housings. Piercing the billet during forging removes the centre segregation zone, which would otherwise remain in the bore of a part drilled from solid bar.
- **Rings.** Seamless rolled and open-die forged rings for bearing races, gear rims, slewing rings and flanged assemblies. Ring rolling produces circumferential grain flow, which suits components loaded in hoop stress.
- **Discs, blocks and plates.** Upset-forged for gear blanks, end covers, die holders and tooling plates. Upsetting works the material through its thickness, which maintains properties in the short-transverse direction.
- **Gear shafts, pinion shafts and crankshafts.** Spindles, bevel gear and crown wheel blanks, and crankshaft forgings. Drivetrain components are the principal application for the grade.
- **Other forged components.** Flanges, couplings, forks, levers, connecting rods and near-net-shape forgings, produced from a drawing, a physical sample or a 3D model.

## Sizes and forging capability

| Product form | Diameter / width | Length / height | Single piece weight |
|---|---|---|---|
| Forged round bar | Ø80 – Ø1200 mm | up to 8000 mm | 20 – 15,000 kg |
| Square / flat / hex bar | 80 – 1000 mm | up to 8000 mm | 20 – 12,000 kg |
| Hollow bar / sleeve | OD Ø200 – Ø2000 mm, ID from Ø80 mm | up to 4000 mm | 50 – 15,000 kg |
| Seamless rolled ring | OD Ø300 – Ø3500 mm | height up to 1000 mm | 50 – 12,000 kg |
| Forged ring | OD Ø300 – Ø4000 mm | height up to 1500 mm | 50 – 20,000 kg |
| Disc / block / plate | up to 1500 mm | thickness up to 800 mm | 20 – 18,000 kg |
| Gear / pinion shaft | Ø100 – Ø1200 mm | up to 8000 mm | 50 – 20,000 kg |

- Delivery condition: +A, +FP, +TH, +S or +N to EN 10052, stated on the order and on the certificate.
- Surface condition: black forged, shot blasted, rough turned, proof machined or finish machined to drawing.
- Machining allowance: normally 5–15 mm per side depending on section size.
- Minimum forging ratio: 3:1, recorded on the certificate.
- Minimum order: one piece. There is no minimum tonnage for 17CrNi16.
- Lead time: normally 20–35 days from drawing approval, subject to billet availability.

## Testing, inspection and certificates

An EN 10204 3.1 mill test certificate is supplied with every 17CrNi16 shipment. It records the chemical analysis, mechanical test results, hardness and delivery condition symbol, together with the heat treatment record, forging ratio, grain size and ultrasonic testing to EN 10228. Where a customer specification requires witnessed inspection, an EN 10204 3.2 certificate through SGS, BV, TÜV or Lloyd's Register is arranged before production starts.

| Test | Method / standard | Reported as |
|---|---|---|
| Chemical analysis | Spectrometer, ladle and product analysis | Element-by-element vs EN 10084 |
| Tensile test | ISO 6892-1 | Rm, Rp0.2, A, Z |
| Impact test | ISO 148-1, Charpy V, temperature to order | Three-value average in J |
| Hardness | Brinell or Rockwell | HBW / HRC, location and delivery condition stated |
| Ultrasonic testing | EN 10228-3 (or ASTM A388 / SEP 1921) | Acceptance class to order |
| Magnetic particle / dye penetrant | EN 10228-1 / EN 10228-2 | Surface indication report |
| Grain size | ASTM E112 / ISO 643 | Grade number, normally 5–8 |
| Non-metallic inclusions | ISO 4967 / ASTM E45 | A, B, C, D ratings |
| Jominy hardenability | EN ISO 642 / SAE J406 | End-quench curve, on request |
| Case depth after carburizing | DIN 50190 | CHD at the hardness limit stated on the drawing |
| Dimensional inspection | CMM, calipers, micrometers | Full dimensional report |

Each forging is stamped with the heat number so it can be traced back to its certificate and to the original steel melt. Records are retained for ten years.

## Applications

17CrNi16 is specified for components that require a hard, wear-resistant surface over a core able to absorb impact loading.

| Industry | Typical components | Reason for the grade |
|---|---|---|
| Automotive and truck | Driving bevel gears, crown wheels, differential pinions, gearbox shafts | Contact fatigue resistance with a shock-tolerant core |
| Gearboxes and drives | Gear blanks, pinion shafts, spline shafts, gear rims | Predictable carburizing response, good dimensional stability |
| Aerospace and heavy machinery | Heavy-duty gear shafts, accessory drive gears | High core strength in medium cross sections |
| Mining and construction | Crawler pins, bushings, sprockets, drive shafts | Abrasion resistance at the surface |
| General engineering | Camshafts, piston bolts, spindles, stopcock and valve parts | Cost-effective alternative to Mo-bearing grades |
| Tooling | Pressing, drawing and deep-drawing tools; woodworking tools | Hard case over a core that resists cracking |

## How to order

Send a drawing, sketch or 3D model to sales@steelforgepieces.com, or call +86-189-2135-9659. Quotations are normally returned within 24 hours on working days.

1. Grade and standard: 17CrNi16 / 1.5918, EN 10084, plus any customer specification.
2. Shape and dimensions: PDF, DWG or STEP, with tolerances and the required machining allowance.
3. Quantity: quantity for this order, and the expected annual volume if applicable.
4. Delivery condition: +A, +FP, +TH, +S or +N, and whether rough turned or finish machined.
5. Heat treatment: whether carburizing and hardening are carried out by the customer or should be included.
6. Required case depth and surface hardness, if carburizing is included.
7. Testing and certificate: EN 10204 3.1 or 3.2, UT acceptance class, impact test temperature.
8. Destination port and Incoterms: FOB Shanghai, CIF or DDP.

## Frequently asked questions

**Is 17CrNi16 the same as 17CrNi6-6?**
Yes. 17CrNi16 and 17CrNi6-6 are two ways of writing the same EN 10084 case hardening steel, material number 1.5918. 17CrNi6-6 is the current EN chemical designation; 17CrNi16 is a compressed spelling still found in older drawings, trading catalogues and steel databases. Quoting material number 1.5918 on the order removes any ambiguity.

**What is the material number for 17CrNi16?**
The material number for 17CrNi16 is 1.5918. The same steel also appears as 17 CrNi 16, 17CrNi6-6, 17CrNi66, 15Cr6Ni6, 16NiCr6, ZF1 and BNC5. Quote 1.5918 on the purchase order, because the material number is recognised by every mill and inspection body.

**What is the chemical composition of 17CrNi16?**
To EN 10084:2008, 17CrNi16 contains 0.14–0.20 % carbon, max 0.40 % silicon, 0.50–0.90 % manganese, 1.40–1.70 % chromium and 1.40–1.70 % nickel, with phosphorus limited to 0.025 % and sulphur to 0.035 %. There is no deliberate molybdenum addition, which is the main difference from 18CrNiMo7-6.

**What do +A, +S, +TH and +FP mean on a 17CrNi16 order?**
They are EN 10052 delivery condition symbols, which define the hardness of the 17CrNi16 forging as delivered. +A is soft annealed, max 229 HBW. +S is treated for cold shearing, max 255 HBW. +TH is treated to a hardness range of 175–229 HBW. +FP is treated to a ferrite-pearlite structure at 156–207 HBW. State the required symbol on the purchase order so that the forging suits the intended machining process.

**What hardness is 17CrNi16 when it is delivered?**
17CrNi16 is delivered in a soft condition so that it can be machined. Depending on the delivery condition ordered, hardness runs from 156 HBW in the +FP condition up to a maximum of 255 HBW in the +S condition. The 58–62 HRC surface is produced only after the finished part has been carburized, quenched and tempered.

**What is the tensile strength of 17CrNi16?**
On a 16 mm test piece to EN 10084, 17CrNi16 reaches 1200 MPa tensile strength after hardening and tempering at 200 °C, with a reduction of area of 57–62 %. In the spheroidize annealed condition (+AC) tensile strength is about 600 MPa. In a carburized part the core typically reaches 900–1200 MPa depending on section size.

**Is 17CrNi16 the same as AISI 4320?**
No. AISI 4320 and 4320H (UNS H43200, H43204) are the American grades most often cross-referenced to 17CrNi16, but they are not interchangeable: AISI 4320 contains 0.20–0.30 % molybdenum and less chromium, so it hardens deeper. Use the cross-reference as a starting point, then confirm composition and hardenability against EN 10084 before substituting.

**Who supplies 17CrNi16 forgings from China?**
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 17CrNi16 (1.5918) forged bars, hollow bars and sleeves, seamless rolled rings, discs, blocks and gear shafts for customers worldwide. Enquiries can be sent to sales@steelforgepieces.com or +86-189-2135-9659.

**What sizes of 17CrNi16 forgings are available?**
Jiangyin Jiangnan Metal Co., Ltd. supplies 17CrNi16 forged round bars from Ø80 mm to Ø1200 mm, forged and seamless rolled rings from Ø300 mm to Ø4000 mm outside diameter, discs and blocks up to 1500 mm, and shafts up to 8000 mm long, with single piece weights from 20 kg to 20 tons. Non-standard sizes are forged to drawing.

**What certification comes with 17CrNi16 forgings?**
Every 17CrNi16 order ships with an EN 10204 3.1 mill test certificate covering chemical analysis, mechanical properties, hardness, delivery condition, heat treatment record, forging ratio, grain size and ultrasonic testing to EN 10228. An EN 10204 3.2 certificate witnessed by SGS, BV, TÜV or Lloyd's Register can be arranged on request.

**Can 17CrNi16 be welded?**
Yes, in the annealed or normalised condition, using a preheat of about 200–250 °C, low-hydrogen consumables and post-weld stress relief. Do not weld 17CrNi16 after carburizing and hardening, because the hardened case will crack. If a weld is needed on a carburized part, mask the area with stop-off paint before carburizing.

## Manufacturer

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin City, Jiangsu Province, China. It manufactures forged bars, hollow bars, sleeves, seamless rolled rings, forged rings, discs, blocks and gear shafts in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys, including 17CrNi16 (1.5918) to EN 10084. Parts are produced to customer drawings and shipped worldwide with EN 10204 3.1 certification.

- Company: Jiangyin Jiangnan Metal Co., Ltd.
- Business: Open-die forging factory / forged component manufacturer
- Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone: +86-189-2135-9659
- Email: sales@steelforgepieces.com
- Website: https://www.steelforgepieces.com/
- Materials: Carbon steel, alloy steel, tool steel, stainless steel, nickel alloys
- Export markets: Europe, North America, South America, Middle East, India, Southeast Asia, Australia

## Related grades

- 17CrNi6-6 (the same steel): https://www.steelforgepieces.com/Alloy-Steel/17CrNi6-6.html
- 18CrNiMo7-6: https://www.steelforgepieces.com/Alloy-Steel/18CrNiMo7-6.html
- 17CrNiMo6: https://www.steelforgepieces.com/Alloy-Steel/17CrNiMo6.html
- 1.6587: https://www.steelforgepieces.com/Alloy-Steel/1.6587.html
- AISI 4317: https://www.steelforgepieces.com/Alloy-Steel/AISI-4317.html
- AISI 4820: https://www.steelforgepieces.com/Alloy-Steel/AISI-4820.html
- 18NCD6: https://www.steelforgepieces.com/Alloy-Steel/18NCD6.html
- 820M17: https://www.steelforgepieces.com/Alloy-Steel/820M17.html
- 822M17: https://www.steelforgepieces.com/Alloy-Steel/822M17.html
- 42CrMo4: https://www.steelforgepieces.com/Alloy-Steel/42CrMo4.html
- AISI 4140: https://www.steelforgepieces.com/Alloy-Steel/AISI-4140.html
- AISI 4340: https://www.steelforgepieces.com/Alloy-Steel/AISI-4340.html

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Citation: Jiangyin Jiangnan Metal Co., Ltd. (2026). 17CrNi16 (1.5918): designation, composition, delivery hardness and forged product forms. https://www.steelforgepieces.com/Alloy-Steel/17CrNi16.html

Standards referenced: EN 10084:2008, EN 10052:1993, EN 10204, EN 10228, DIN 50190.

Data on this page is compiled from EN 10084:2008, EN 10052:1993 and published steel mill data sheets, and is given for guidance. It does not replace the material certificate supplied with your order.