4142 Steel Round Bar | Precision Grinding & Supply

4142 Alloy Steel Round Bar: 4142 is a medium-carbon chromium-molybdenum low-alloy steel often used for hardenable precision shafts and mechanical components.

Download Mozaic 4142 Alloy Steel Round Bar technical reference sheet (PDF)

4142 Alloy Steel Round Bar — Grade and Specifications

Identification, product standards and ordering information
Requirement	Technical / purchase-order detail
Material / product	4142 Alloy Steel Round Bar
Alloy or grade identity	SAE/AISI 4142, Cr-Mo alloy steel
Applicable purchasing standard	ASTM A29/A29M or particular bar grade standard
Supply condition	Specify Q&T, annealed or normalized state and hardness or tensile requirements
Typical uses	Shafts, pins, axles and heavily machined steel components
Dimensional processing	Define diameter, finish, tolerance, bar straightness and cutting requirements separately

This reference page does not constitute a mill test report or a guarantee of available stock. Mechanical properties, chemistry and certifications depend on the actual ordered alloy, condition and product standard.

Applications and Grade-Selection Guidance

4142 contains nominally more carbon than 4140; neither is interchangeable with leaded 41L40. Representative applications include shafts, pins, axles and heavily machined steel components. Product purchasing should identify the alloy family or exact UNS designation and the conditions of service. Grade substitutions require engineering approval; a similar grade name does not demonstrate equivalent performance.

Round Bar Processing and Precision Finishing

Mozaic Precision Metals offers order-specific centerless grinding, straightening, saw cutting, polishing, chamfering and packaging. Buyers should specify finished outside diameter, diameter tolerance, length, surface finish, material condition, inspection and lot traceability independently. Actual grinding capability depends on the bar dimensions, alloy and heat-treatment state.

Related Grades and Material Guides

4140 round bar 2 — related grade or more specific sourcing information
41l40 steel — related grade or more specific sourcing information

Request Material Sourcing or Grinding

Send your grade/product drawing, material standard, supplied condition, starting/finished sizes, tolerance, quantity and certifications to sales@mozaicprecision.com, call 847-637-8379 or request a quotation.

Why Choose 4142 Steel?

4142 alloy steel offers a strong balance of toughness, wear resistance, and machinability. Its ability to be heat-treated makes it a versatile option for components that require durability under high stress, such as gears, shafts, fasteners, and structural parts. With reliable mechanical properties and excellent performance, 4142 steel is widely used in automotive, aerospace, construction, and heavy equipment industries.

Custom 4142 Steel Solutions

Whether you require standard sizes or custom dimensions, Mozaic Precision Metals supplies 4142 steel round bars with precision finishes and tight tolerances. We also provide a wide range of value-added services to ensure your materials meet your exact specifications, including:

Saw cutting

Machining

Heat treating

Centerless grinding and polishing

Partner with Mozaic Precision Metals

From small-batch orders to large-scale supply, Mozaic Precision Metals delivers high-quality 4142 steel with consistency and reliability. Our leadership team has over 60 years of combined experience in precision grinding, ensuring that every product meets industry standards and customer expectations.

Contact us today to request a quote and secure 4142 steel bar stock for your next project.

Key Advantages of 4142 Steel

Exceptional Toughness: Absorbs shock and withstands heavy loads without cracking or deforming, ideal for gears, axles, and other high-stress parts.

Versatility: Easily machined and welded, offering cost efficiency in both fabrication and production.

Excellent Wear Resistance: Performs well in abrasive environments, making it valuable for construction, mining, and industrial machinery.

Heat-Treatable: Can be hardened and tempered to improve surface strength and wear resistance, extending service life.

Durability: Maintains strength and performance under repeated stress, ensuring long-term reliability.

Applications of 4142 Steel

Due to its strength and toughness, 4142 alloy steel is widely used across industries that demand performance under high stress. Typical applications include:

Gears, shafts, and axles

Machine parts and industrial components

Mining and construction equipment

Heavy-duty fasteners and spindles

Tooling applications requiring hardness and wear resistance

4142 Steel from Mozaic Precision Metals

At Mozaic Precision Metals, we provide high-quality 4142 alloy steel round bars manufactured to precise tolerances with superior surface finishes. Our products are trusted by industries that require consistent strength, toughness, and wear resistance.

With over 60 years of combined experience in precision grinding, our leadership team ensures every order meets the highest standards of performance and reliability. Whether you need small-batch supply or bulk production, Mozaic Precision Metals delivers steel solutions tailored to your project needs.

Contact us today to request a quote for 4142 steel bar stock and discover why manufacturers across automotive, mining, and construction rely on Mozaic Precision Metals for durable and dependable materials.

4142 Alloy Steel Round Bar