Last updated: . Published by Jiangyin Jiangnan Metal Co., Ltd.
What is 42CD4 steel?
42CD4 is a medium-carbon Cr-Mo alloy steel from the former French NF (AFNOR) standards. The name encodes its chemistry: about 0.42% carbon, with chromium (C) and molybdenum (D). In Europe it has been replaced by the EN 10083-3 grade 42CrMo4, material number 1.7225, so drawings may use either name for the same steel.
After quenching and tempering, 42CD4 reaches high tensile strength with good toughness and fatigue resistance. Its good hardenability lets it keep useful strength through thick sections, which is why it is widely used for heavy forged shafts, rings, gears and flanges.
42CD4 equivalent grades
| Country / standard | Grade | Match |
|---|---|---|
| France – AFNOR NF | 42CD4 | Original grade |
| Europe – EN 10083-3 | 42CrMo4 / 1.7225 | Direct equivalent |
| USA – AISI / SAE | 4140 | Close equivalent |
| Japan – JIS G4053 | SCM440 | Close equivalent |
| China – GB/T 3077 | 42CrMo | Close equivalent |
| UK – BS 970 | 709M40 (EN19) | Close equivalent |
Chemical limits differ slightly between standards. Please name one governing standard on your drawing or purchase order.
42CD4 chemical composition
| C | Si | Mn | P | S | Cr | Mo |
|---|---|---|---|---|---|---|
| 0.38–0.45 | ≤ 0.40 | 0.60–0.90 | ≤ 0.025 | ≤ 0.035 | 0.90–1.20 | 0.15–0.30 |
We can also melt to NF, GB, ASTM or customer-specific limits. For machinability, the resulfurized variant 42CrMoS4 is available.
42CD4 mechanical properties (quenched and tempered)
| Diameter d (mm) | Yield Re (MPa) | Tensile Rm (MPa) | Elongation A (%) | Reduction Z (%) | Impact KV (J) |
|---|---|---|---|---|---|
| ≤ 16 | ≥ 900 | 1100–1300 | ≥ 10 | ≥ 40 | – |
| 16–40 | ≥ 750 | 1000–1200 | ≥ 11 | ≥ 45 | ≥ 35 |
| 40–100 | ≥ 650 | 900–1100 | ≥ 12 | ≥ 50 | ≥ 35 |
| 100–160 | ≥ 550 | 800–950 | ≥ 13 | ≥ 50 | ≥ 35 |
| 160–250 | ≥ 500 | 750–900 | ≥ 14 | ≥ 55 | ≥ 35 |
Heavy forgings above 250 mm are produced to properties agreed on the order, for example to EN 10250-3 or the customer's specification.
How we manufacture 42CD4 forgings
- MeltingSteel is melted by EAF, refined by VOD and, where required, electroslag remelted (ESR) for higher cleanliness.
- Open-die forging or ring rollingIngots are forged on open-die presses, or pierced and rolled into seamless rings, typically between about 1150 °C and 850 °C.
- Heat treatmentSupplied annealed, normalized, or hardened and tempered: hardening at 820–860 °C with oil or polymer quench, tempering at 540–680 °C.
- Machining and inspectionRough or finish machining to drawing, dimensional check, hardness and mechanical testing.
- Ultrasonic testing and certificationUT to EN 10228-3, SEP 1921 or ASTM A388; certificates to EN 10204 3.1 or 3.2 with third-party inspection.
42CD4 forged products we supply
- 42CD4 forged rings and seamless rolled rings
- 42CD4 forged shafts, spindles and eccentric shafts
- 42CD4 forged flanges and tube sheets
- 42CD4 forged discs and blanks
- 42CD4 forged round bars and blocks
- 42CD4 forged gears and gear blanks
- 42CD4 forged sleeves and bushings
- 42CD4 forged pipes, tubes and nozzles
- 42CD4 forged valve stems, seat rings and bodies
- Custom open-die forging pieces to drawing
Applications of 42CD4 forgings
| Industry | Typical 42CD4 forged parts |
|---|---|
| Pumps and compressors | Shafts and rolled rings for chemical pumps, plunger pumps and gas compressors |
| Pressure equipment | Shafts, pipes, tubes, tube sheets and flanges for pressure vessels, air receivers and shell-and-tube heat exchangers |
| Process plants | Flanges, rings and pipes for columns, towers, tanks, silos, process modules and preheaters |
| Oil and gas | Bushings, sleeves and discs for subsea and deepwater production systems; nozzles and shafts for wellheads and Christmas trees |
| Valves | Valve stems, seat rings, blocks and bodies for ball, check, globe, gate and plug valves and strainers |
| Power transmission | Rings, spindles, bars and gears for turbines, gearboxes and power generators |
| Mills and heavy machinery | Crankshafts and forgings for cement, sugar and concrete mills and mixers; wheels, manifolds and rolls |
| Other industries | Shipbuilding, pulp and paper, pharmaceutical and biochemical equipment, crystallizers, industrial air and nitrogen generators |
42CD4 forging FAQ
What is 42CD4 steel?
42CD4 is the former French AFNOR designation for a chromium-molybdenum alloy steel for quenching and tempering. In the current European standard EN 10083-3 the same grade is called 42CrMo4, material number 1.7225. It combines high strength, good toughness and good hardenability, which makes it a common choice for forged shafts, rings, flanges and gears.
What are the equivalent grades of 42CD4?
The direct European equivalent of 42CD4 is 42CrMo4 (1.7225) to EN 10083-3. Close international equivalents are AISI/SAE 4140 (USA), SCM440 (JIS, Japan), 42CrMo (GB, China) and 709M40 / EN19 (BS, UK). Chemical limits differ slightly between standards, so the governing standard should be stated on the order.
Is 42CD4 the same as AISI 4140?
They are very close but not identical. Both are Cr-Mo steels with about 0.4% carbon. AISI 4140 allows higher manganese (0.75-1.00%) and a narrower molybdenum range (0.15-0.25%) than 42CrMo4/42CD4. For most forged components they are interchangeable, but the drawing or purchase order should name one governing standard.
Which 42CD4 forged products does Jiangyin Jiangnan Metal manufacture?
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu, China, manufactures 42CD4 forged rings, seamless rolled rings, forged shafts, flanges, discs, round bars, gears, sleeves, bushings and forged pipes to customer drawings.
What heat treatment is available for 42CD4 forgings?
42CD4 forgings can be supplied annealed, normalized, or hardened and tempered (quenched and tempered). Typical ranges are hardening at 820-860 °C with oil or polymer quench, and tempering at 540-680 °C depending on the required strength.
How are 42CD4 forgings inspected and certified?
Jiangnan Metal ultrasonically tests 42CD4 forgings to EN 10228-3, SEP 1921 or ASTM A388 as specified, and supplies material certificates to EN 10204 3.1, or EN 10204 3.2 with third-party inspection.
How can I get a quotation for 42CD4 forgings?
Send the drawing or dimensions, quantity, delivery condition and testing requirements to sales@steelforgepieces.com or call +86-189-2135-9659. Jiangyin Jiangnan Metal Co., Ltd. will reply with a price and lead time.
About the 42CD4 forging manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The company manufactures forged rings, seamless rolled rings, shafts, flanges, discs, bars and custom forgings in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys, and ships to customers worldwide.
Jiangyin Jiangnan Metal Co., Ltd. – Open-Die Forging FactoryNo.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Phone: 0086-189-2135-9659
Email: sales@steelforgepieces.com