# 34CrNiMo4 Forgings: Forged Bars, Rings, Shafts and Discs

Jiangyin Jiangnan Metal Co., Ltd. | Open-die forging factory, China
URL: https://www.steelforgepieces.com/Alloy-Steel/34CrNiMo4.html
Last updated: 2026-09-11

34CrNiMo4 is a Ni-Cr-Mo alloy steel for quenched and tempered forgings. It is used for parts that need high strength and good toughness in large sections. Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu, China. We forge 34CrNiMo4 bars, hollow bars, seamless rolled rings, discs and gear shafts to customer drawings.

- 34: about 0.34% carbon (0.30-0.38%)
- CrNiMo: alloyed with chromium, nickel and molybdenum

## 34CrNiMo4 Specifications

| Item | Details |
|---|---|
| Steel type | Ni-Cr-Mo alloy steel, quenched and tempered grade |
| Carbon | 0.30-0.38% |
| Alloying elements | Cr 1.30-1.70%, Ni 1.30-1.70%, Mo 0.15-0.30% |
| Steel making | Electric arc furnace, vacuum degassing, bottom poured ingots |
| Products | Forged bars, hollow bars, sleeves, seamless rolled rings, blocks, discs, gear shafts, pinion shafts |
| Testing | ASTM E381, ASTM E45, ASTM E112, eddy current testing |
| Manufacturer | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |

## 34CrNiMo4 Chemical Composition (%)

| Element | Min | Max |
|---|---|---|
| C (Carbon) | 0.30 | 0.38 |
| Si (Silicon) | - | 0.40 |
| Mn (Manganese) | 0.50 | 0.80 |
| Cr (Chromium) | 1.30 | 1.70 |
| Ni (Nickel) | 1.30 | 1.70 |
| Mo (Molybdenum) | 0.15 | 0.30 |
| P (Phosphorus) | - | 0.035 |
| S (Sulfur) | - | 0.035 |

Fe: balance. Other standards or tighter limits are available on request.

## 34CrNiMo4 Forged Products

We supply 34CrNiMo4 in the following forged forms. Sizes are made to order.

| Product | Shapes |
|---|---|
| Forged bars | Round bars, rods, square bars, rectangular bars, flat bars, hex bars |
| Hollow forgings | Hollow bars, sleeves, bushes, bushings, pipes, tubes, barrels, casings, shells, cylinders, hubs, housings |
| Rings | Seamless rolled rings, forged rings |
| Blocks and discs | Forged blocks, discs, plates |
| Shafts | Gear shafts, pinion shafts, spindles |
| Custom parts | Other open die forgings to drawing |

## Steel Making and Testing

1. Melting: electric arc furnace.
2. Vacuum degassing: required for every heat.
3. Ingot casting: bottom poured ingots.
4. Forging: open die forging or ring rolling.
5. Heat treatment: as per order, normally quenched and tempered.
6. Testing: macro etch, inclusions, grain size and surface testing.

| Test | Standard | Requirement |
|---|---|---|
| Macrostructure (hot hydrochloric acid etch, transverse slice) | ASTM E381 | S-2, R-2, C-2 |
| Non-metallic inclusions | ASTM E45, Method A | As per order |
| Grain size | ASTM E112 | Finer than grade 5 |
| Surface cracks and defects, rolled bars | Eddy current testing | All rolled bars |

## Heat Treatment and Applications

34CrNiMo4 forgings are normally supplied quenched and tempered (QT). Heat treatment temperatures and mechanical properties are agreed with the customer for each order and shown on the mill test certificate.

Common parts: shafts, gear shafts, pinion shafts, axles, couplings, spindles, rings and discs for gearboxes, mining machinery, wind power, marine and heavy equipment.

## FAQ

### What is 34CrNiMo4 steel?

34CrNiMo4 is a Ni-Cr-Mo alloy steel with about 0.34% carbon. It is used in the quenched and tempered condition for shafts, gears, rings and discs that need high strength and good toughness in large sections.

### What is the chemical composition of 34CrNiMo4?

C 0.30-0.38%, Si max 0.40%, Mn 0.50-0.80%, Cr 1.30-1.70%, Ni 1.30-1.70%, Mo 0.15-0.30%, P max 0.035%, S max 0.035%, Fe balance.

### What 34CrNiMo4 forgings do you supply?

Forged round, square, rectangular, flat and hex bars; hollow bars, sleeves, bushings, tubes, barrels, casings, shells, cylinders, hubs and housings; seamless rolled rings and forged rings; forged blocks, discs and plates; gear shafts, pinion shafts and spindles; and other open die forgings to drawing.

### What tests are done on 34CrNiMo4 forgings?

Macro etch to ASTM E381 with rating S-2, R-2, C-2; non-metallic inclusions to ASTM E45 Method A; grain size to ASTM E112, finer than grade 5; eddy current testing for surface defects on rolled bars. The steel is melted in an electric arc furnace, vacuum degassed and cast as bottom poured ingots.

### Can you supply 34CrNiMo6 or AISI 4340 instead of 34CrNiMo4?

Yes. We also forge 34CrNiMo6 (1.6582), AISI 4340 and other Ni-Cr-Mo grades. The composition limits are different in each standard, so please give the standard and grade on your drawing or order.

### Who makes 34CrNiMo4 forgings in China?

Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China. Phone +86 189 2135 9659, email sales@steelforgepieces.com.

### How do I get a quote?

Email sales@steelforgepieces.com or call +86 189 2135 9659. Please send the drawing or dimensions, quantity, standard, heat treatment and mechanical properties, testing requirements and destination port.

## Related Grades

[34CrNiMo6](https://www.steelforgepieces.com/Alloy-Steel/34CrNiMo6.html), [34CrNiMo6V](https://www.steelforgepieces.com/Alloy-Steel/34CRNIMO6V.html), [1.6582](https://www.steelforgepieces.com/Alloy-Steel/1.6582.html), [AISI 4340](https://www.steelforgepieces.com/Alloy-Steel/AISI-4340.html), [1.6565](https://www.steelforgepieces.com/Alloy-Steel/1.6565.html), [40NiCrMo6](https://www.steelforgepieces.com/Alloy-Steel/40NiCrMo6.html), [40NCD7](https://www.steelforgepieces.com/Alloy-Steel/40NCD7.html), [35NCD6](https://www.steelforgepieces.com/Alloy-Steel/35NCD6.html), [817M40](https://www.steelforgepieces.com/Alloy-Steel/817M40.html), [SNCM439](https://www.steelforgepieces.com/Alloy-Steel/SNCM439.html), [30NiCrMo8](https://www.steelforgepieces.com/Alloy-Steel/30NiCrMo8.html), [42CrMo4](https://www.steelforgepieces.com/Alloy-Steel/42CrMo4.html)

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
Open-die forging factory
Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China
Tel: +86 189 2135 9659
Email: sales@steelforgepieces.com
Website: https://www.steelforgepieces.com/