Type AQ is a wear and abrasion resisting iron that is readily machinable as-cast but may be “air hardened” after machining with minimum risk of cracking or distortion. Type AQ is easily heat treated and locally hardened.
Type GM-60 possesses exceptionally high physical properties, including good impact strength and shock resistance – responds well to heat treatment and surface hardening. Type GM machines to a very fine finish and is recommended for heavy section castings where pressure tightness is required.
Type GA-50 combines high strength, toughness, wear resistance and damping capacity with excellent machinability. Responds well to heat treatment, local and surface hardening.
Type GC-40 combines good strength with low coefficient of friction and self lubricating properties. It is easily machinable with a fine, dense, close grain structure.
Type GE-30 combines improved strength and solidity with higher machining feeds and speeds than ordinary gray iron.
Type GF-20 is designed principally for high machinability and is used where ultimate strength is not an important factor.
| PROPERTY | TYPE AQ | TYPE GM-60 | TYPE GA-50 | TYPE GC-40 | TYPE GE-30 | TYPE GF-20 |
|---|---|---|---|---|---|---|
| Tensile Strength-psi | 50/65,000 | 60,000 | 50,000 | 40,000 | 30,000 | 20,000 |
| Proportional Limit-psi .01% permanent set | 25,000 | 25,000 | 22,000 | 14,500 | 11,500 | 9,500 |
| Modulus of Elasticity-psi | 22,000,000 | 21,500,000 | 20,000,000 | 16,500,000 | 13,000,000 | 9,000,000 |
| Modulus of Rigidity-psi | 9,500,000 | 9,500,000 | 8,750,000 | 7,250,000 | 5,550,000 | 4,000,000 |
| Poisson's Ratio | 0.33 | 0.33 | 0.32 | 0.30 | 0.27 | 0.24 |
| Modulus of Rupture-psi | 93,000 | 93,000 | 90,000 | 80,000 | 61,000 | 41,000 |
| Compression Strength-psi | 200,000 | 200,000 | 180,000 | 150,000 | 120,000 | 90,000 |
| Fatigue Strength-psi | 30,000 | 25,000 | 22,000 | 17,500 | 13,500 | 11,000 |
| Shear Strength-psi | 53,000 | 50,000 | 40,000 | 30,000 | 21,550 | |
| Single Impact-Izod (0.798") Diameter Unnotched Bar | 30-40 | 30-40 | 25-35 | 12-20 | 6-12 | 4-9 |
| Brinell Hardness (Nominal) | 280-550 | 230 | 220 | 190 | up to 160 | 150 |
| Machinability Rating (Dalcher) | 52 | 50 | 48 | 47 | 38 | 30 |
| Thermal Conductivity 50-450°F. BTU/Hr/ Sq. Ft./In. Thickness/°F | 355 | 350 | 325 | 290 | --- | |
| Coefficient of Thermal Expansion Per °F. from 100° to 750°F. | .00000675 | 0.00000640 | 0.00000650 | 0.00000670 | 0.00000680 | 0.00000700 |
| Specific Gravity | 7.34 | 7.34 | 7.31 | 7.25 | 7.06 | 6.80 |
| Solid Contraction (Patternmaker's Shrinkage) | 5/32"-6/32" /ft. (1.3-1.5%) | 5/32"-6/32" /ft. (1.3-1.5%) | 5/32"-6/32" /ft. (1.3-1.5%) | 4/32"-5/32" /ft. (1.0-1.3%) | 1/10"-1/8" /ft. (0.8-1.0%) | 1/10" /ft. (0.8%) |