A blue bar that separates the head section of the site from the body

G2 Gray Iron

Dura-Bar G2 is a pearlitic gray iron containing Type A graphite. Our continuous cast bars made to this robust specification are a good fit for a variety of applications, due to its good machinability, wear resistance and vibration damping properties. G2 is built around ASTM A48 Class 40 gray iron, which is validated from a separately cast bar. To learn more, download the G2 Gray Iron Grade Product Brief.

Typical Applications



Fluid Power:

Cylinder blocks, Glands, Manifolds, Pistons, Rotors, Spools, Valves


Bushings, Gears, Gibs, Housings, Pulleys, Rams, Sheaves, Side Frames, Slides, Spindles, Ways


Aluminum Molds Plates, Cams, Chain Sheaves, Core Boxes, Dies, Pattern Plates, Wheels

Oil and Gas:

Bridge Plugs, Cement Plugs, Cones, Mandrels, Retainers, Slips

Power Transmission:

Gears, Pulleys

Pump and Compressor:

Gears, Housings, Liners, Pistons, Rollers, Rotors, Seals

Steel Mill:

Continuous Caster Rolls, Foot Rolls, Table Rolls, Torch Rolls


Brake Rotors, Cylinder Liners, Gears, Lash Adjusters, Pulleys, Shock Absorber Pistons, Valve Guides, Valve Seat Inserts


The microstructure will contain Type VII, A, size 4–6 graphite as defined in ASTM A247. The matrix is fully pearlitic. The edge or rim will consist of Type D, size 6–8 graphite in a matrix that is a combination of pearlite and ferrite. Chill carbides will be less than 5% in any field at 100x and are well dispersed.

A graph detailing the microstructure of the G2

Chemical Composition

Carbon and silicon targets are specified for each bar size in order to control the size and shape of the graphite flake.

Sulfur0.07% Max
Phosphorus0.12% Max

Mechanical Properties

Brinell hardness values for nominal as-cast diameters are shown in the table. Hardness properties listed are minimum and maximum across the bar. Hardness values for rectangles and squares are a function of the height and width ratios and will be supplied on request.

Size Range

0.625 - 0.75016 - 19
0.751 - 1.50019 - 38
1.501 - 2.00038 - 51
2.001 - 3.00051 - 76
3.001 - 6.00076 - 152



Tensile strength is determined from a separately cast, ASTM "B" test bar. Separately cast test bars will meet the minimum strength in pounds per square inch in the table below. Additionally, a test bar is removed from the continuous cast bar for reference, as tensile strength varies with section thickness and bar diameter.

Mechanical Properties
Tensile strength psi (min)40,000
Yield strength psi (min)n/a*
Elongation (min)n/a*

* Gray iron will not yield/elongate before fracture. The behavior of gray iron is non-ductile.

Call us today to discuss your application at 888-DURA-BAR (888.387.2227) or click to complete our quote form.