Gray Iron Bar Grades
Continuous cast gray iron bar with ASTM Type VII flake graphite — Class 20 through Class 45 for strength, vibration damping, wear resistance and clean machining finish.
Continuous cast gray irons contain flake graphite in matrix structures that range from fully pearlitic to pearlite plus ferrite, depending on the grade.
The flake configuration corresponds to ASTM Type VII and is available in Type D size 6–8 or Type A size 4–6 — giving a predictable, machinable microstructure across every bar section.
The matrix structure controls machinability, strength, hardness and wear characteristics. A fully pearlitic matrix delivers the best mechanical properties while still machining cleanly; bars containing ferrite in the matrix are easier to machine but lower in strength and wear resistance.
Gray iron grades & mechanical properties
| Brand | Tensile (min) | Hardness | Matrix |
|---|---|---|---|
| EN-GJL-150 / GG15 / FC150 | ≥ 20 ksi (140 MPa) | HB 150–180 | Ferrite + pearlite |
| EN-GJL-200 / GG20 / FC200 | ≥ 30 ksi (205 MPa) | HB 170–210 | Pearlite + ferrite |
| EN-GJL-250 / GG25 / FC250 | ≥ 35 ksi (240 MPa) | HB 180–230 | Pearlite |
| EN-GJL-300 / GG30 / FC300 | ≥ 40 ksi (275 MPa) | HB 200–250 | Pearlite |
| EN-GJL-350 / GG35 / FC350 | ≥ 45 ksi (310 MPa) | HB 220–260 | Fully pearlitic |
Mechanical properties measured on samples taken at 1/4 diameter (round) or 1/4 diagonal (square / rectangle). Custom grades available on request.
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