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65-45-12 Ductile Iron

Dura-Bar 65-45-12 ductile iron contains nodular graphite in a matrix of ferrite with small amounts of pearlite. The ferritic structure gives excellent machinability with good surface finishes along with optimal impact strengths, fatigue properties, electrical conductivity and high magnetic permeability. This iron has approximately the same tensile and yield strengths as AISI 1020 steel in the as-rolled condition. This specification conforms to ASTM A536 grade 65-45-12. Download the 65-45-12 Ductile Iron Product Brief.

A stack of 65-45-12 Iron rods piled on one an other

Typical Applications:



Fluid Power

Cylinder Blocks, End Caps, Gear Rack Housings, Gerotors, Glands, Manifolds, Pistons, Rotors, Valves

Glass Mold

Bank Molds, Plungers


Bushings, Chuck Bodies, Die Blocks, Flywheels, Gears, Housings, Journals, Pulleys, Rams, Rotary Tables, Side Frames, Spindle Housings, Tie Rod Nuts


Plunger Pin

Power Transmission

Coupling Hubs, Gears, Pulleys, Sprockets

Pump and Compressor

Gears, Housings, Pistons, Rotary Screws, Rotors


Coupling Hubs, Gears, Pulleys, Rail Spacers, Sprockets


The microstructure consists of Types I & II nodular graphite as defined in ASTM A247. The matrix is ferrite with approximately 5–25% pearlite. The edge or rim will have a higher nodular count and will be mostly ferrite. Chill carbides will be less than 5% in any field at 100x and will be well dispersed.

A graph detailing the Microstrucure of the 65-45-12

Chemical Composition

*Carbon and silicon targets are specified for each bar size in order to maintain mechanical properties. Magnesium is added as an inoculant to produce nodular graphite.

Sulfur0.025% Max
Phosphorus0.05% Max

Mechanical Properties

Hardness properties for various diameters are shown in the table. Hardness properties listed are minimum and maximum across the bar. For rectangles, squares and shapes, the hardness properties will depend on minimum and maximum section thickness and will be supplied on request.

Size Ranges

Inches Millimeter
1.000 25-51
2.001 3.000
3.001 6.000
6.001 20.000



Tensile strength is determined from a longitudinal test specimen taken from mid-radius of the as-cast bar. In bars under 2.0" diameter, elongation will be 9% minimum.

Mechanical Properties
Tensile strength psi (min)65,000
Yield strength psi (min)45,000
Elongation (min)12%

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