Materials

AISI 4130

Material:

• A chromium-molybdenum (chromoly) alloy steel containing approximately 0.30% carbon.

• Known for its excellent balance of strength, toughness, weldability, and machinability.

Mechanical Properties:

• High strength-to-weight ratio.

• Good toughness and fatigue resistance.

• Readily heat treated for increased strength and hardness.

• Typical tensile strength ranges from ~90–150 ksi depending on heat treatment.

Corrosion Resistance:

• Similar to most alloy steels, with limited natural corrosion resistance.

• Protective coatings or plating are typically required in corrosive environments.

Manufacturing Considerations:

• Excellent weldability compared to higher-carbon alloy steels.

• Good machinability in normalized and annealed conditions.

• Suitable for forging, machining, and heat treatment.

Applications in Fasteners & Components:

• Aerospace hardware and structural components.

• Oil & gas equipment.

• High-strength bolts, studs, and pins.

• Motorsports and performance applications.

AISI 4140

Material:

• A chromium-molybdenum alloy steel containing approximately 0.40% carbon.

• One of the most widely used alloy steels for engineered fasteners and critical components.

Mechanical Properties:

• Excellent combination of strength, toughness, and fatigue resistance.

• Through-hardening capability allows uniform properties throughout the cross-section.

• Typical tensile strength ranges from ~95–180 ksi depending on heat treatment.

Corrosion Resistance:

• Limited corrosion resistance; protective coatings are generally recommended.

• Performs well in demanding industrial environments when properly protected.

Manufacturing Considerations:

• Good machinability in annealed condition.

• Excellent response to heat treatment.

• Suitable for forging, machining, and induction hardening.

Applications in Fasteners & Components:

• High-strength bolts, studs, and nuts.

• Oilfield and pressure vessel fasteners.

• Shafts, gears, and couplings.

• Heavy industrial and power generation equipment.

AISI 4142

Material:

• Chromium-molybdenum alloy steel similar to 4140, but with slightly higher carbon content (~0.42%).

• Provides increased hardness and strength after heat treatment.

Mechanical Properties:

• Higher hardness and wear resistance than 4140.

• Excellent fatigue strength.

• Good toughness when properly heat treated.

• Frequently used in high-strength fastener applications.

Corrosion Resistance:

• Comparable to other Cr-Mo alloy steels.

• Requires coating or plating for corrosion protection.

Manufacturing Considerations:

• Good machinability in annealed condition.

• Excellent heat-treat response.

• Often selected where additional hardness is required beyond 4140 capabilities.

Applications in Fasteners & Components:

• High-strength studs and bolts.

• Heavy-duty industrial hardware.

• Oil & gas pressure-containing equipment.

• Wear-resistant shafts and mechanical components.