AISI 4140 Gr F91 Alloy Steel Bars

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AISI 4140 Gr F91 Alloy Steel Bars Specification

Coating Type
Available with Black, Bright or Machined finish

Size
Customized as per requirement

Diameter
16mm to 350mm

Corrosion Resistant
Yes, with proper surface protection

Tensile Strength
585760 MPa

Hardness
180250 HB

Product Form
Forged, Rolled, Annealed Bars

Material Composition %
C: 0.080.12%, Cr: 8.09.5%, Mo: 0.851.05%, V: 0.180.25%

Recyclable
Yes

Heat Resistance
High, suitable for elevated temperatures

Product Name
AISI 4140 Gr F91 Alloy Steel Bars

Steel Type
Alloy Steel

Steel Product Type
Bars

Grade
AISI 4140 Gr F91

Thickness
Available from 16mm to 350mm

Shape
Round, Hex, Square

Steel Standard
ASTM A182/F91, AISI 4140

Surface
Bright, Black, Polished

Composition
Cr-Mo-V composition

Application
Industrial machinery, automotive, construction, oil & gas, power plants

Dimension (L*W*H)
Custom sizes as per requirement

Weight
As per bar size and length

Color
Metallic Grey

Material Grade
F91

Finish Type
Smooth, Peeled or Turned

Usage
Power generation, valves, flanges, shaft manufacturing

About AISI 4140 Gr F91 Alloy Steel Bars

What Are Specification AISI 4140 Gr F91 Alloy Steel Bars?

Specification :	EN, DIN, JIS, ASTM, BS, ASME, AISI
Standard Specification :	ASTM A182 / ASME SA182
Size :	5mm to 500mm Dia in 100mm to 6000mm Length
Thickness :	0.5mm to 500mm Diameter
Diameter :	10 mm To 200 mm
Length :	1000 mm Long To 6000 mm Long
Form :	Round, Square, Hex (A/F), Rectangle, Billet, Ingot, Forging Etc
Finish :	Black, Bright Polished, Rough Turned, NO.4 Finish, Matt Finish, BA Finish

Equivalent material Of AISI 4140 Gr F91 Alloy Steel Bars?

STANDARD	UNS	WERKSTOFF NR.
AISI 4140	G41400	1.7225

Chemical Composition Of AISI 4140 Gr F91 Alloy Steel Bars?

Grade		C	Cr	Si	S	Mn	P	Mo
AISI 4140	min.	0.38	0.8	0.15	-	0.75	-	0.15
AISI 4140	max.	0.43	1.10	0.35	0.04	1.00	0.04	0.25

Mechanical Properties Of AISI 4140 Gr F91 Alloy Steel Bars?

Grade	Tensile Strength (ksi) min	Elongation (% in 50mm) min	Yield Strength 0.2% Proof (ksi) min	Hardness
AISI 4140	855	20	621	197

Superior Mechanical and Thermal Properties

AISI 4140 Gr F91 Alloy Steel Bars are engineered to deliver high tensile strength (585760 MPa) and hardness (180250 HB), coupled with the ability to withstand elevated temperatures. Their enhanced alloy composition ensures reliable performance in sectors where strength and heat resistance are critical, making them an ideal choice for components such as shafts, valves, and flanges.

Flexible Dimensions and Finishing Options

Offered in various shapes including round, hex, and square, these alloy steel bars are available in thicknesses from 16mm up to 350mm. Customers can specify both length and dimension requirements for tailored solutions. Various surface finishesbright, black, polished, smooth, machinedensure compatibility with specific operational needs and aesthetic preferences.

Manufacturing Excellence and Compliance

Conforming to industry standards like ASTM A182/F91 and AISI 4140, these steel bars are produced through forging, rolling, and annealing processes. Rigorous quality checks and controlled delivery conditions such as normalization and tempering guarantee durable performance and material consistency, suited for critical industrial and construction projects.

FAQs of AISI 4140 Gr F91 Alloy Steel Bars:

Q: How are the AISI 4140 Gr F91 Alloy Steel Bars typically processed for use?

A: These bars undergo forging, rolling, and annealing, and are supplied in normalized and tempered or annealed conditions to enhance mechanical properties and ensure structural reliability. Additional surface finishes or custom-cut dimensions can be provided according to end-use requirements.

Q: What applications are best suited for AISI 4140 Gr F91 Alloy Steel Bars?

A: These alloy steel bars are widely used in power plants, oil & gas facilities, industrial machinery, automotive parts, construction components, valves, flanges, and shaft manufacturing, where high strength, durability, and heat resistance are necessary.

Q: When is it necessary to heat treat or apply surface protection to the bars?

A: Heat treatment is recommended when specific mechanical or performance criteria must be met, such as increased hardness or strength. Surface protection coatings are advisable for applications where enhanced corrosion resistance or a specific surface quality is required.

Q: Where can custom sizes or finishes be requested for these steel bars?

A: Custom sizes, diameters, and finishes can be ordered directly from manufacturers, exporters, or suppliers. Specifications such as length, width, surface finish, and machining requirements should be provided at the time of order to ensure precise delivery.

Q: What are the weldability and machinability characteristics of AISI 4140 Gr F91 Alloy Steel Bars?

A: The bars offer good machinability, making them suitable for precision components. Welding is feasible but requires pre- and post-weld heat treatment to ensure joint integrity and minimize stress or cracking, given their alloyed composition.

Q: How does using these alloy steel bars benefit industrial projects?

A: Utilizing these bars contributes to increased component life, reliable performance under stress and heat, and adaptability to various shapes and sizes. Their high yield and tensile strength, coupled with excellent machinability and available corrosion resistance, add value to critical assemblies.

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