G2S Gray Iron

Dura-Bar G2S is a high strength highly pearlitic gray iron. It combines both superior strength and surface hardenability attributes. By an addition of molybdenum, G2S maintains excellent strength throughout the cross-section of the bar. A minimum of 40,000 psi tensile strength from the mid-radius is achieved. Using additional alloying elements, the carbon-rich material needed for effective induction or flame hardening is an additional compliment to G2S. G2S is ideal for applications where strength, hardenability, and creep resistance are required. To learn more, download the G2S Gray Iron Product Brief

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Dura-Bar Gray Iron G2S


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 consisting of 80% pearlite. Chill carbides will be less than 5% in any field at 100x and are well dispersed.

Center Area

100x, etched in 5% Nital

Edge Area

100x, etched in 5% Nital

Heat Treat Response

Dura-Bar G2S can be hardened by fast methods, such as flame and induction hardening. Carbon-rich pearlite in the rim of the continuous cast bars will effectively transform to martensite (hard phase of iron). Contrasted with a more ferritic rim, continuous cast bars can result in untransformed microstructure and thus a less ideal material hardness after heat treatment.

In addition to surface hardening, Dura-Bar G2S can be heat treated by conventional quench and temper methods. Get more details including typical Jominy end quench curve, methods and cycle times, and temperature effects by downloading the Dura-Bar Heat Treating Guide.

Stock Sizes

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Dura-Bar round products

As-cast round bars are made to clean up at the nominal size. Additional stock is added to allow for out-of-round and normal imperfections in the as-cast surface. Stock allowance is a function of the bar diameter — see Stock Allowances for details. Other finishes available are Centerless Grinding and Centerless Turning, for demanding tolerance applications.

Grade Shape Diameter (in) Surface Weight (lb/ft) Length Bundle Quantity

Custom Shapes

Sizes can be designed to meet your requirements.

All custom shapes are special order and are quoted individually at minimum run quantities. Contact us to find out if a Dura-Bar custom shape will work for your part.

Technical Specifications

Chemical Composition

Carbon and silicon targets are specified for each bar size in order to control the size and shape of the graphite flake. Alloying elements are used to promote enhanced tensile strength and to stabilize the pearlitic structure.

Element Percentage
Carbon 2.60 - 3.75%
Silicon 1.80 - 3.00%
Manganese 0.60 - 0.95%
Sulfur 0.07% Max
Phosphorus 0.12% 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 BHN
Inches mm Min Max
2.500 - 6.000 64 - 152 207 290


Tensile strength is determined from a test bar removed from the mid-radius of a continuous cast bar. Test bars from the mid-radius will meet the minimum 40,000 psi listed in the table below. Since mid-radius test bars meet a 40,000 psi class of iron, separately cast bars are cast for reference only.

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.

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

Dura-Bar®: Continuous Cast Iron Bar Stock

1800 West Lake Shore Drive
Woodstock, IL 60098


800-BAR-MILL (227-6455)

Fax: 815-338-1549 Sales

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