What is 21NiCrMo2?
21NiCrMo2 is a low alloy nickel chromium molybdenum case hardening (carburizing) steel with the EN material number 1.6523. It is equivalent to AISI 8620, JIS SNCM220 and BS 805M20. After carburizing, quenching and tempering the steel has a hard wear resistant surface over a tough core, so it is widely specified for gears, pinions, shafts and heavily loaded machine parts.
Jiangyin Jiangnan Metal Co., Ltd. produces 21NiCrMo2 forgings to customer requirement, from single prototype pieces to production batches. The steel is melted by EAF + LF + VD (electric arc furnace, ladle furnace, vacuum degassing) to keep inclusion levels low, then open die forged and heat treated to the condition required. Annealed, normalized, and hardened and tempered conditions are available, and carburizing can be arranged for finished parts.
Chemical Composition of 21NiCrMo2
| Element | C | Si | Mn | P | S | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|
| Range (%) | 0.17-0.23 | max 0.40 | 0.65-0.95 | max 0.035 | max 0.035 | 0.35-0.70 | 0.40-0.70 | 0.15-0.25 |
Balance iron. The actual heat analysis is stated on the mill test certificate supplied with each order.
21NiCrMo2 Equivalent Grades
| Standard / Region | Designation |
|---|---|
| EN (material number) | 21NiCrMo2 / 1.6523 |
| USA (AISI / SAE) | 8620 / 8620H |
| Japan (JIS) | SNCM220 |
| UK (BS) | 805M20 |
| China (GB) | 20CrNiMo |
The grades listed are the nearest comparable specifications. Please confirm the exact standard required when ordering.
21NiCrMo2 Forged Product Forms
We supply 21NiCrMo2 as open die forgings and seamless rolled rings in the following shapes, machined to your size or drawing:
- Forged rings and seamless rolled rings
- Round bars and forged blocks
- Forged flanges
- Disks and discs
- Shafts, spindles and eccentric shafts
- Gear blanks and pinions
- Sleeves and bushings
- Forged tubes and hollow bars
- Tube sheets
- Near net shape forgings to drawing
Applications of 21NiCrMo2 Forgings
The combination of core toughness and a hard carburized surface puts 21NiCrMo2 into service across power transmission and heavy industry:
Power transmission
Gears, pinions, gear boxes, turbine and gas compressor drive parts.
Pumps
Shafts for chemical pumps and plunger pumps.
Pressure and heat exchange
Flanges, tube sheets and tubes for pressure vessels, air receivers, shell and tube heat exchangers.
Oil and gas
Subsea and deepwater production parts, wellhead and Christmas tree components.
Compressors and power generation
Industrial air compressors, power generators and nitrogen generators.
Valves
Valve stems, seat rings, bodies and blocks for ball, gate, globe, check and plug valves.
Mills and process plant
Cement mills, sugar mills, mixers, crystallizer and processing units.
Heavy machinery
Shipbuilding, rolls, wheels, manifolds, paper and pulp, pharmaceutical and biochemical plant.
Manufacturing, Testing and Certification
- Melting: EAF + LF + VD for low inclusion, clean steel.
- Forging: open die forging and seamless ring rolling.
- Heat treatment: annealing, normalizing, hardening and tempering, carburizing on request.
- Ultrasonic testing: to EN 10228-3, SEP 1921 or ASTM A388 as specified.
- Certificate: EN 10204 3.1, or EN 10204 3.2 with third party inspection.
- Made to order: send the drawing or dimensions and we will quote price and lead time.
21NiCrMo2 Frequently Asked Questions
What is 21NiCrMo2 steel used for?
What is 21NiCrMo2 equivalent to?
Is 21NiCrMo2 a case hardening steel?
What is the chemical composition of 21NiCrMo2?
Can Jiangyin Jiangnan Metal supply 21NiCrMo2 to my drawing?
Need 21NiCrMo2 forgings?
Send the size or drawing and we will quote our best price and lead time.