What 1.6643 steel is and where it is used
1.6643 is a low-carbon alloy steel designed to be case hardened. The carbon content is deliberately held near 0.22% so that the core stays tough and impact-tolerant, while nickel, chromium and molybdenum supply the hardenability needed for the carburised surface layer to transform fully to martensite on an oil quench.
Nickel keeps the case tough at high hardness and raises core toughness in heavier sections. Chromium and molybdenum promote stable carbide formation, which produces the hard running surface a gear tooth or a bearing journal needs. At 0.30–0.40% molybdenum, 1.6643 has appreciably more hardenability than the widely used 8620-type carburising steels, so it holds core hardness in sections where a leaner grade would fall away.
Section size and cooling rate matter more for 1.6643 than for a through-hardening steel, because the grade is bought for a hardened surface over a tough core. Forgings are usually specified over bar stock where a continuous grain flow follows the load path. Gear blanks, pinion shafts, heavy sleeves and rolled rings are the common cases.
Chemical composition of 1.6643
Ladle analysis, mass fraction in weight percent. Balance iron with residual elements.
| Element | Symbol | Minimum | Maximum | Role in the grade |
|---|---|---|---|---|
| Carbon | C | 0.20 | 0.25 | Kept low so the core stays tough after carburising |
| Silicon | Si | 0.15 | 0.35 | Deoxidiser; raises tempering resistance slightly |
| Manganese | Mn | 0.75 | 1.00 | Hardenability; ties up sulphur |
| Phosphorus | P | — | 0.035 | Residual, limited for toughness |
| Sulphur | S | — | 0.040 | Residual; can be restricted on request |
| Chromium | Cr | 0.40 | 0.60 | Carbide former; case hardness and wear resistance |
| Nickel | Ni | 0.40 | 0.70 | Case and core toughness |
| Molybdenum | Mo | 0.30 | 0.40 | Hardenability in heavy sections; temper embrittlement resistance |
This band coincides with SAE/AISI 8822 as published in SAE J404 and SAE J1249. Jiangyin Jiangnan Metal Co., Ltd. restricts sulphur and phosphorus below the standard maxima on request where impact toughness or ultrasonic cleanliness is critical. The certified analysis for each heat appears on the EN 10204 mill test certificate that ships with the order.
Mechanical properties of 1.6643
Figures below are indicative for the delivery conditions shown. Use them for design and enquiry. They are not a purchase specification.
| Condition | Tensile Rm MPa |
Yield Rp0.2 MPa |
Elongation A % |
Reduction Z % |
Impact KV J |
Hardness |
|---|---|---|---|---|---|---|
| Annealed (+A), for machining | — | — | — | — | — | ≤ 217 HBW |
| Normalised (+N) | ≥ 640 | ≥ 400 | ≥ 15 | ≥ 40 | — | 180–230 HBW |
| Core, carburised + quenched + tempered | ≥ 792 | ≥ 539 | ≥ 21 | ≥ 43 | ≥ 21 | ≈ 222 HBW |
| Case, after carburising and quenching | Surface layer, not a tensile condition | 58–62 HRC | ||||
Properties vary with section size, cooling rate, case depth and tempering temperature. Certified values for the heat supplied are issued on the EN 10204 3.1 or 3.2 mill test certificate. Send the required core hardness, case depth and section size and Jiangyin Jiangnan Metal Co., Ltd. will confirm what is achievable before the order is placed.
Forging and heat treatment of 1.6643
Typical shop practice for this class of nickel–chromium–molybdenum carburising steel. Cycles are adjusted for each part according to section thickness and the required case depth.
| Operation | Temperature | Cooling | Purpose |
|---|---|---|---|
| Forging | 1150 → 850 °C | Slow cool, covered | Shape the part and close ingot porosity |
| Normalising | 880–920 °C | Still air | Refine grain after forging, even out structure |
| Annealing | 650–700 °C | Furnace cool | Soften for machining, relieve stress |
| Carburising | 900–930 °C | Hold to case depth | Raise surface carbon to about 0.8% |
| Hardening | 820–840 °C | Oil quench | Transform the case to martensite |
| Tempering | 150–200 °C | Air | Relieve quench stress, retain case hardness |
1.6643 is normally supplied by Jiangyin Jiangnan Metal Co., Ltd. in the annealed or normalised condition so the buyer can machine the part before carburising. State the delivery condition you need on the enquiry. Carburising is generally carried out after machining, by the part maker, because machining after case hardening is expensive and risks cutting through the case.
1.6643 forged product forms and sizes
Every form below is produced from the same forging route: ingot or bloom, upsetting and drawing on an open-die press, then ring rolling or saddle work where the shape calls for it.
| Forged form | Typical size range | Where it is used |
|---|---|---|
| Round bars and rods | Ø 80–1,200 mm, length to 12 m | Shaft and pinion blanks, machined components |
| Square, rectangular and flat bars | Thickness 60–800 mm, width to 1,500 mm | Die blocks, machine bases, keyed sections |
| Hexagonal bars | Across flats 50–400 mm | Tooling stems, drive components |
| Hollow bars, sleeves, bushings and bushes | OD 150–2,500 mm, wall from 30 mm | Bearing housings, wear sleeves, liners |
| Pipes, tubes, barrels, casings, shells and cylinders | OD 200–2,500 mm, length to 6 m | Pressure bodies, extruder barrels, hydraulic cylinders |
| Seamless rolled rings | OD 200–4,000 mm, height to 1,000 mm | Gear rims, slewing rings, bearing races, flanges |
| Forged rings and hubs | OD 200–3,000 mm | Wheel hubs, coupling hubs, retaining rings |
| Discs, disks, blocks and plates | Ø to 2,500 mm, thickness 50–1,000 mm | Gear blanks, blind flanges, tool plates |
| Gear shafts, pinion shafts and spindles | Ø 100–1,000 mm, length to 12 m | Gearbox input and output shafts, mill pinions, rotor spindles |
| Forged to customer drawing | 20 kg – 30,000 kg per piece | Near-net shapes that save machining time and material |
Sizes outside these bands are quoted case by case. Parts can be supplied as-forged, rough turned or bored, or finish machined to drawing.
As-forged
Black surface with forging allowance left on. Lowest cost route when you machine in house.
Rough machined
Turned, bored or faced with stock left for finishing. Removes decarburised skin and lets ultrasonic testing be done on a clean surface.
Finish machined
Delivered to final drawing dimensions and tolerances, ready for carburising or assembly.
How Jiangyin Jiangnan Metal forges 1.6643
Open-die forging deforms the steel between flat or shaped dies without enclosing it in a cavity. It suits low volumes, large sections and one-off drawings, because the same press makes any shape without new tooling.
| Step | What happens | Why it matters |
|---|---|---|
| Steel making | EAF or converter steel, ladle refined, vacuum degassed. ESR on request. | Controls gas content and inclusion cleanliness |
| Ingot or bloom | Cast to the size that gives the required forging ratio | Sets how much the structure can be worked |
| Heating | Soak to 1150 °C in a controlled furnace | Uniform temperature prevents cracking on the first blow |
| Open-die forging | Upset and draw, forging ratio typically 3:1 or higher | Closes porosity and aligns grain flow with the part axis |
| Ring rolling | Pierce, then roll on a radial-axial mill for ring shapes | Produces a seamless circumferential grain flow |
| Heat treatment | Normalise or anneal, in furnaces with recorded charts | Delivers the machinable condition you ordered |
| Machining | Rough turn, bore or finish machine to drawing | Removes decarburised skin, prepares for inspection |
| Inspection and release | Chemistry, mechanical tests, UT, dimensional report | Produces the EN 10204 certificate that travels with the goods |
Testing, inspection and certification
Jiangyin Jiangnan Metal Co., Ltd. supplies every 1.6643 forging with an EN 10204 3.1 mill test certificate as standard. Third-party witnessed 3.2 certification is available on request.
| Test | Standard | Included |
|---|---|---|
| Chemical analysis, ladle and product | ASTM E415 / ISO 14284 | Standard |
| Tensile test | ASTM A370 / ISO 6892-1 | Standard |
| Impact test, Charpy V-notch | ASTM E23 / ISO 148-1 | On request |
| Hardness, Brinell or Rockwell | ASTM E10 / ASTM E18 | Standard |
| Ultrasonic testing | ASTM A388 / EN 10228-3 / SEP 1921 | On request |
| Magnetic particle testing | ASTM E709 / EN 10228-1 | On request |
| Grain size and inclusion rating | ASTM E112 / ASTM E45 | On request |
| Jominy end-quench hardenability | ASTM A255 / ISO 642 | On request |
| Dimensional report | To customer drawing | Standard |
| Third-party witness | TUV, SGS, BV, Lloyd's Register | On request |
State the governing specification, acceptance class and test temperature on the enquiry. Where a customer specification calls for tests not listed here, Jiangyin Jiangnan Metal Co., Ltd. will confirm before quoting whether they can be met in house or through an accredited laboratory.
Applications for 1.6643 forgings
1.6643 is chosen where a part must resist surface wear and contact fatigue while surviving shock loads through its core. Most of the demand comes from power transmission.
Industrial gearboxes
Gear blanks, gear rims, pinion shafts and input shafts for mill, crane and conveyor drives.
Mining and cement
Mill pinions, crusher shafts, kiln support rollers and heavy bushings running in abrasive conditions.
Wind and marine
Planet carriers, ring gear blanks, slewing ring races and propulsion shafting components.
Construction and earthmoving
Track pins and bushings, final drive gears, swing pinions and axle shafts.
Oil, gas and process
Pump and compressor shafts, wear sleeves, extruder barrels and heavy-wall cylinders.
Machine tools
Spindles, feed screws, worm shafts and bearing housings where dimensional stability matters.
1.6643 equivalent and comparable grades
Cross-references are a selection guide. They do not authorise substitution. Composition bands, permitted residuals and test requirements differ between standards, so name the governing specification on the purchase order.
| Grade | Standard | Relationship to 1.6643 |
|---|---|---|
| SAE / AISI 8822 | SAE J404, SAE J1249 | Same published composition band. The usual American cross-reference. |
| AISI 8620 | SAE J404 | Same Ni–Cr family with lower molybdenum (0.15–0.25%). Leaner and cheaper, less hardenable in heavy sections. |
| 1.6523 / 20NiCrMo2-2 | EN ISO 683-3 | The European counterpart of 8620. Choose over 1.6643 for lighter sections. |
| SNCM 220 | JIS G4053 | Japanese carburising grade in the same family. |
| 18CrNiMo7-6 | EN ISO 683-3 | Higher chromium and nickel. Step up when core strength in very heavy gears is the limit. |
| 17CrNiMo6 | DIN 17210 | Common alternative for large carburised gears and pinions. |
| AISI 4140 / 42CrMo4 | SAE J404 / EN ISO 683-2 | Through-hardening, not carburising. Choose when you want uniform strength rather than a hard case. |
Frequently asked questions about 1.6643
What is 1.6643 steel?
1.6643 is a nickel–chromium–molybdenum case-hardening (carburising) alloy steel identified by its German material number. It carries roughly 0.20–0.25% carbon with 0.40–0.70% nickel, 0.40–0.60% chromium and 0.30–0.40% molybdenum, which gives a hard, wear-resistant carburised case over a tough low-carbon core. It is used for gears, pinions, shafts, spindles and bushings.
Is 1.6643 the same as AISI 8822?
The composition band published for 1.6643 coincides with SAE/AISI 8822 as defined in SAE J404 and J1249: C 0.20–0.25%, Mn 0.75–1.00%, Si 0.15–0.35%, Cr 0.40–0.60%, Ni 0.40–0.70%, Mo 0.30–0.40%. The two are normally treated as interchangeable for forging purposes, but they are written against different standards, so state which specification governs your order and confirm it against the mill test certificate.
What forged shapes are available in 1.6643?
Jiangyin Jiangnan Metal Co., Ltd. forges 1.6643 into round bars, square bars, rectangular and flat bars, hexagonal bars, hollow bars, sleeves, bushings, cylinders, casings, shells, hubs and housings, seamless rolled rings, forged rings, discs, blocks and plates, and gear shafts, pinion shafts and spindles. Parts can also be forged to a customer drawing.
What is the maximum size of a 1.6643 forging?
Jiangyin Jiangnan Metal Co., Ltd. produces 1.6643 forgings from 20 kg to 30 tonnes per piece. Typical ranges are round bars 80–1,200 mm diameter, seamless rolled rings 200–4,000 mm outside diameter, discs up to 2,500 mm diameter and shafts up to 12 m long.
How is 1.6643 heat treated?
1.6643 is forged between about 1150 and 850 °C and then normalised at 880–920 °C, or annealed at 650–700 °C for machining. In service the part is carburised at 900–930 °C, oil quenched from 820–840 °C and tempered at 150–200 °C, which typically gives a case hardness of 58–62 HRC over a tough core.
What certification is supplied with 1.6643 forgings?
Every 1.6643 forging from Jiangyin Jiangnan Metal Co., Ltd. ships with an EN 10204 3.1 mill test certificate as standard, covering heat number, ladle analysis, heat treatment condition and mechanical test results. EN 10204 3.2 certification witnessed by a third party such as TUV, SGS, BV or Lloyd's Register is available on request, as are ultrasonic testing reports to ASTM A388 or EN 10228-3.
Who supplies 1.6643 open-die forgings in 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 supplies 1.6643 forgings worldwide. The company can be reached at sales@steelforgepieces.com or +86 189 2135 9659.
Can 1.6643 forgings be made to a drawing?
Yes. Send a 2D drawing, 3D model or a written dimension list with the governing specification, quantity and required delivery condition to sales@steelforgepieces.com. Jiangyin Jiangnan Metal Co., Ltd. quotes forged-to-shape, rough-machined and finish-machined 1.6643 parts, and will advise the nearest standard forging size if a custom size is not economical.
About the supplier
Jiangyin Jiangnan Metal Co., Ltd.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The company forges bars, hollow bars, sleeves, seamless rolled rings, discs, blocks and gear shafts in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys, in single pieces from 20 kg to 30 tonnes, and ships worldwide with EN 10204 3.1 or 3.2 certification.
Jiangyin is in the Yangtze River Delta between Shanghai and Nanjing, about two hours from Shanghai Port and Ningbo Port. Much of China's forging and special-steel industry is based in the same area. Enquiries are answered in English and Chinese.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Type
- Open-die forging factory
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town,
Jiangyin City, Jiangsu Province, China - Phone
- +86 189 2135 9659
- sales@steelforgepieces.com
- Website
- steelforgepieces.com
Get a price for your 1.6643 forging
Send a drawing and you will normally have a quotation within one working day. To price a part accurately we need:
- A drawing, 3D model or finished dimensions, and the forging allowance if you already know it
- Grade and governing specification, for example 1.6643 or SAE 8822
- Delivery condition: as-forged, annealed, normalised, rough machined or finish machined
- Quantity and target delivery date
- Testing and certification required: EN 10204 3.1 or 3.2, ultrasonic class, any third-party witness
sales@steelforgepieces.com · +86 189 2135 9659 · No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China