AISI 4140/42CrMo4 Seamless Tube

AISI 4140/42CrMo4 Seamless Tube is a high-strength, low-alloy steel known for its excellent toughness, fatigue resistance, and hardenability. When manufactured into seamless tubes, it is widely used in demanding industrial applications requiring high mechanical strength and durability.

Advantages

1. High Strength & Durability: AISI 4140/42CrMo4 Seamless Tube has good mechanical properties, including high tensile strength and toughness.Better Fatigue Resistance: No welded seams mean fewer weak points, enhancing lifespan under cyclic stresses.

2. Excellent Hardenability & Heat Treatability: Can be quenched & tempered to achieve desired hardness.

3. Good Machinability: Easier to machine than high-carbon steels, reducing tool wear.

4. Corrosion Resistance: The steel composition provides moderate resistance to corrosion, especially when properly maintained.

5. Seamless Construction: The seamless nature of the tube ensures uniformity and reliability in high-pressure applications.

6. Versatility: Suitable for a wide range of applications, including hydraulic cylinders, pneumatic cylinders, and precision engineering components.

Material Composition

Element	AISI 4140 (ASTM)	42CrMo4 (DIN/EN)
Carbon (C)	0.38–0.43%	0.38–0.45%
Chromium (Cr)	0.80–1.10%	0.90–1.20%
Molybdenum (Mo)	0.15–0.25%	0.15–0.30%
Manganese (Mn)	0.75–1.00%	0.60–0.90%
Silicon (Si)	0.15–0.35%	0.15–0.40%
Phosphorus (P) (max)	≤0.035%	≤0.025%
Sulfur (S) (max)	≤0.040%	≤0.035%
Iron (Fe)	Balance	Balance

Mechanical Properties

Property	Metric Units	Imperial Units
Tensile Strength	850-1000 MPa	123,000-145,000 psi
Yield Strength	650-780 MPa	94,000-113,000 psi
Elongation at Break	12-18%	12-18%

Delivery Conditions

Designation	Symbol	Description
Cold finished (hard)	BK	Tubes do not undergo heat treatment following the final cold forming and thus have a rather high resistance to deformation.
Cold finished (soft)	BKW	The final heat treatment is followed by cold drawing involving limited deformation.Appropriate further processing allows a certain degree of cold forming(e.g.bending,expanding).
Cold finished and stress-relieved	BKS	Heat treatment is applied following the last cold forming process.Subject to appropriate processing conditionsthe increase in the residual stresses involved enables both forming and machining to a certain degree.
Annealed	GBK	The last cold forming process is followed by annealing in a controlled atmosphere
Normalized	NBK	The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.

Delivery Condition: SR,BK, BK+S, GBK, NBK

ID Size : 20mm – 1500mm

Length: max 16m

Type: Seamless, Hot Rolled, Cold Rolled, Cold Drawn

Straightness: ≤ 0.5/1000

Roughness: as request

Tolerance INT: as request

Protection: Anti-rust oil on inside and outside surface, plastic caps in both ends.

Packing: Bundle with steel strip and PE sheet or Plywood case