G2A Gray Iron

Dura-Bar G2A contains type D graphite in a predominantly pearlitic matrix. The fine graphite structure allows excellent surface finish and is normally used in permanent mold applications requiring optimal strengths and wear resistance.

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Gray Iron G2A


The microstructure will contain Type VII, D, size 6-8 graphite as defined in ASTM A247. The matrix is predominantly pearlite. The edge or rim will be similar to the center. Chill carbides will be less than 5% in any field at 100x and will be well dispersed.

Center Area

100x, etched in 5% Nital

Edge Area

100x, etched in 5% Nital

Heat Treat Response

G2 Dura-Bar can be oil quench hardened from 1600° F (885° C) to a minimum hardness of Rockwell C 50 on the outside of the bar. The inside diameter hardness will be less than Rockwell C 50. Lower quench hardness on the inside diameters are a result of larger graphite flakes and not as a loss of matrix hardness. Get more details including typical Jominy end quench curve, methods and cycle times, and temperature effects by downloading the Dura-Bar Heat Treating Guide.


Dura-Bar Gray G2A is a non-stock grade, which can be ordered in volume quantities from our distributors.

Technical Specifications

Chemical Composition

Carbon and silicon targets are specified for each bar size in order to maintain mechanical properties. Titanium is added as an inoculant to produce the Type D graphite structure.

Element Percentage
Carbon 2.60 - 3.75%
Silicon 2.30 - 3.00%
Manganese 0.20 - 0.40%
Sulfur 0.025% 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, maximum across the bar. Hardness values for rectangles and squares are a function of the height and width ratios and will be provided on request.

Size Range BHN
Inches mm Min Max
0.750 - 20.000 16 - 508 248 311

The tensile strength will be approximately 40,000 psi, as determined from a longitudinal test specimen taken from mid-radius of the as-cast bar. The tensile data is not a minimum, but rather the typical expected tensile strength. Anticipated tensile data for shapes, including squares and rectangles, will be provided on request.

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

Typical Applications

Glass Mold:

Blank Molds, Plungers

Visit our applications list for more detailed information on G2A applications.

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Dura-Bar®: Continuous Cast Iron Bar Stock

1800 West Lake Shore Drive
Woodstock, IL 60098


800-BAR-MILL (227-6455)

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