1018 Cold Rolled ASTM A108 Carbon Steel Rectangle Bar 0.375 x 0.625 in

Our review of the 1018 Cold Rolled ASTM A108 Carbon Steel Rectangle Bar finds it best suited to small shops and fabricators who need a reliable, machinable raw material with good surface finish and consistent dimensions. The single biggest reason to consider this bar is its balance of workability and strength: 1018 cold-rolled steel offers moderate tensile properties while remaining easy to machine, weld, and form. For projects that require flat faces and sharp corners in a tight tolerance rectangular format, this bar delivers predictable results without the complexity or cost of higher-alloy steels.

Key Features

• MATERIAL COMPOSITION: 1018 cold rolled ASTM A108 carbon steel provides a low-carbon, general-purpose alloy that is easy to machine and weld for common fabrication tasks.
• VERSATILE APPLICATIONS: The rectangular bar is ideal for machining shafts, pins, brackets and fixture components where moderate strength and good surface finish are required.
• MECHANICAL PROPERTIES: Good ductility and consistent machinability make it suitable when parts need to be formed, drilled, or tapped without excessive tool wear.
• SHAPE SPECIFICATIONS: The rectangular format with flat surfaces and sharp corners allows precise layout and fixturing for tight-tolerance engineering work.
• MACHINING CHARACTERISTICS: Offers good weldability and can be case hardened when extra wear resistance is needed, giving flexibility for finishing operations.

Who It's For

This rectangular 1018 bar is for hobby machinists, small fabrication shops, toolmakers, and manufacturers producing moderate-duty mechanical parts. It suits users who need an affordable, easy-to-work steel that machines cleanly and accepts welding and forming without specialized equipment.

Those requiring high-strength alloy steels, stainless corrosion resistance, or heavy structural sections should look elsewhere; this grade is not intended for high-temperature service or extreme load-bearing components where alloyed steels or heat-treated materials are needed.

Pros & Cons

Pros

• Consistent cold-rolled finish gives flat faces and clean edges that simplify machining and measurement.
• Good general-purpose machinability and weldability reduce cycle times for common shop operations.
• Moderate strength and ductility make it versatile for brackets, pins, and small shafts.
• Case hardening option available for applications needing improved wear resistance after machining.

Cons

• Low-carbon composition means it cannot achieve the high hardness or strength of alloy steels without additional processing.
• Not corrosion resistant, so finish or coating is required for outdoor or corrosive environments.

Specifications

Material	1018 Cold Rolled ASTM A108 Carbon Steel
Shape	Rectangle bar
Cut length	72 in
Cross section	0.375 in x 0.625 in
Finish	Smooth cold-rolled surface
Typical uses	Machining, welding, cold forming, general fabrication
Workability	Good machinability and weldability; can be case hardened

Our Verdict

The 1018 cold rolled rectangular bar is a pragmatic choice for machinists and fabricators who need an affordable, easy-to-work steel with a clean finish and reliable dimensions. It represents good value for general-purpose mechanical parts and fixtures, provided the project does not require high alloy strength or corrosion resistance.

Frequently Asked Questions

Can this bar be welded?
Yes. 1018 cold rolled steel has good weldability for common welding processes when appropriate pre- and post-weld practices are followed.

Is this material heat treatable to high hardness?
Not to high alloy steel hardness by simple heat treatment; it can be case hardened after machining to improve surface wear resistance.

Is the length exact?
The product is offered as a 72 ft cut length, providing a long continuous bar for fabrication and multiple part cuts.