17CrNi16 Forgings (1.5918)

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 your 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 a drawing callout is ambiguous, send it to sales@steelforgepieces.com before ordering. We will confirm the material number it resolves to and quote against that number, so that the certificate supplied with the parts matches the drawing.

17CrNi16 chemical composition (EN 10084)

17CrNi16 contains 0.14–0.20 % C, 0.50–0.90 % Mn, max 0.40 % Si, 1.40–1.70 % Cr and 1.40–1.70 % Ni, with phosphorus limited to 0.025 % and sulphur to 0.035 %. There is no deliberate molybdenum addition. Jiangyin Jiangnan Metal Co., Ltd. re-checks every heat by spectrometer against these limits before the billet enters the furnace.

* 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. Tighter internal limits on P, S and oxygen can be agreed at order stage for aerospace and wind gearbox work.

Mechanical properties and delivery hardness of 17CrNi16

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

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.

Where no symbol is stated on the purchase order, Jiangyin Jiangnan Metal supplies 17CrNi16 forgings soft annealed (+A), which is suitable for most machining operations. State the symbol explicitly if the process requires one of the other conditions.

Why large 17CrNi16 forgings do not reach data-sheet values

The 1200 MPa figure above 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.

17CrNi16 heat treatment and forging temperatures

17CrNi16 is forged at 1100–850 °C, normalised at 850–880 °C in air, soft annealed at 650–700 °C in the furnace, carburized at 880–980 °C, core hardened at 830–870 °C in oil, case hardened at 780–820 °C in oil and tempered at 150–200 °C.

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. Confirm the intended cycle on the purchase order so the delivery condition matches your heat treater's process.

17CrNi16 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.

17CrNi16 or 18CrNiMo7-6: which to specify

Where the grade selection is not settled, send the part weight, section thickness and required case depth to sales@steelforgepieces.com. Our metallurgist will make a recommendation before the quotation is issued.

17CrNi16 forged product forms we manufacture

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. The product families below cover most requirements; where the appropriate form is not clear from the drawing, send it and we will advise.

Bars: round, square, flat and hexagonal

Round, square, rectangular, flat and hexagonal 17CrNi16 bar, forged rather than rolled, supplied black, peeled, rough turned or ground. These are the usual starting blanks for pinions, spindles, piston bolts and camshafts.

Hollow bars, sleeves, bushes and cylinders

17CrNi16 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. It also reduces machining time on thick-walled components.

Seamless rolled rings and forged rings

Seamless rolled and open-die forged 17CrNi16 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 17CrNi16 discs, blocks and plates 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

Gear shafts, pinion shafts, spindles, bevel gear and crown wheel blanks, and crankshaft forgings in 17CrNi16. Drivetrain components are the principal application for the grade. The tooth flank carries contact pressure while the tooth root carries bending fatigue, and both requirements must be met by a single material.

Other forged components

Flanges, couplings, forks, levers, connecting rods and near-net-shape 17CrNi16 forgings, produced from a drawing, a physical sample or a 3D model.

Available sizes and forging capability

17CrNi16 is forged from Ø80 mm bar up to Ø4000 mm rings, with discs and blocks to 1500 mm, shafts to 8000 mm long and single piece weights between 20 kg and 20 tons. Sizes within these limits are produced routinely. For dimensions close to the upper limits, confirm feasibility before finalising the design.

• 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, confirmed when the order is placed.
• Minimum forging ratio: 3:1, recorded on the certificate.
• Minimum order: one piece. There is no minimum tonnage for 17CrNi16, and prototype quantities are quoted on the same basis as production batches.
• Lead time: normally 20–35 days from drawing approval, subject to billet availability at the time of order.

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.

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.

What 17CrNi16 forgings are used for

17CrNi16 is specified for components that require a hard, wear-resistant surface over a core able to absorb impact loading. Typical parts include driving bevel gears, crown wheels, pinion shafts, camshafts, piston bolts, spindles and transmission shafts in automotive, truck, aerospace, mining and general mechanical engineering.

How to order 17CrNi16 forgings

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.

The following information is required to price a 17CrNi16 forging. Supplying it with the enquiry avoids a round of clarification questions.

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 we are carburizing.
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 about 17CrNi16

Related grades and forged products

The same steel written the EN way: 17CrNi6-6 (1.5918) forgings. Other case hardening and alloy steel grades open-die forged by Jiangyin Jiangnan Metal Co., Ltd.:

• 17CrNi6-6
• 18CrNiMo7-6
• 17CrNiMo6
• 1.6587
• AISI 4317
• AISI 4820
• 18NCD6
• 820M17
• 822M17
• 42CrMo4
• AISI 4140
• AISI 4340
• 34CrMo4
• SCM440
• Inconel 617
• 17-4PH

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. Last reviewed 9 September 2026.