ASTM A108 Cold Finished Squares, Rounds, Hexagons, Flats

Kloeckner Metals stocks a variety of cold finished products including ATSM A108 Cold Finished Squares, Rounds, Hexagons, and Flats.

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Typical Standards

GradeSize Range
A108 Cold Finished Squares7/16" - 2 1/2"
A108 Cold Finished Rounds1/4" - 4"
A108 Cold Finished Hexagons7/16" - 2 1/2"
A108 Cold Finished Flats3/8" x 1" - 1 1/2" x 4"

General Info About A108 Cold Finished Squares, Rounds, Hexagons, Flats

ASTM A108 steel is a medium carbon and alloy steel that has up to 39 grades that are defined by their chemical composition. This steel is typically cold finished, but it can also be cold drawn, cold rolled, ground, heat treated, hot wrought, polished, and turned.

ASTM A108 can be machined and welded, but it is not as suited to these processes as a lower carbon steel. A108 is more easily cracked than other steel because of its medium carbon content.

It is typically used in construction applications and in heavy machinery. Its high strength makes it suitable for parts in heavy machinery and in shafting. This steel is important for vehicle building and mechanical engineering as well.

More Details About A108 Cold Finished Squares, Rounds, Hexagons, Flats

  • Advantages/Disadvantages


    • A108 steel can hold heavy weight due to its high core strength.
    • It is good for construction applications because of its high strength.
    • It is suitable for welding.


    • A108 can be easily cracked due to its higher carbon content.
  • Industries

    ATSM A108 steel is typically used in the construction industry. Some grades of A108 are used for vehicle and machine engineering. This steel is used for parts that have a higher strength demand.

  • Applications

    Typical applications for A108 include parts for heavy machinery and construction. Some applications include gears, drilling parts, and shafts. It can also be used to create parts for a car that need to be extra strong.

  • Machining

    ATSM A108 steel is not as easily machinable as some other lower carbon steels. Its medium carbon content makes it more prone to cracking when compared to other steel. It is still possible, but it may be more difficult.

  • Welding

    It is suitable for welding, but it is more difficult to weld when compared to low-carbon steel. The carbon content of steel is the determining factor of the steel’s weldability, and the higher the carbon content, the less easy it is to weld. A108 is medium carbon steel meaning it is harder to weld than lower carbon steel, but easier to weld than higher carbon steel.

  • Heat Treatment

    A108 steel is often heat treated. This process makes the steel stronger than it already was, and many industries find this valuable for their specific applications.

Chemical Properties


Mechanical Properties

Tensile Strength, Ultimate699 MPa10,100
Tensile Strength, Yield157 MPa22,700
Elongation at Break (in 50mm)32%32%
Poissons Ratio0.27-0.300.27-0.30
Brinell Hardness324324

Frequently Asked Questions

  • What is the difference between A108 and AISI 1018?


    AISI 1018 steel is typically hot rolled while A108 steel is typically cold rolled. AISI 1018 steel has a lower carbon content than A108. A108 steel is heavier than 1018. 1018 has easier machinability and weldability because of its lower carbon content when compared to A108.

  • What is A108M?


    A108M is the metric equivalent version of A108. This is the name used in countries that use the metric system instead of the imperial system. The USA and Liberia use the imperial system, while pretty much every other country uses the metric system.

  • What is the difference between cold finished squares, rounds, hexagons, and flats?

    Squares are solid rods of steel that have four sides and are shaped like a square. Rounds are solid rods of steel that are shaped like a circle. Hexagons are long, solid steel rods that have six sides and are shaped like a hexagon. Flats are long, thin strips of steel. They are flat-rolled steel cut into thin strips.

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