Gray Iron

Gray Iron has been used for thousands of years for many purposes. Its composition may be primarily graphite flakes and either pearlite or ferrite, or sometimes a composition of both. Some benefits of using Gray Iron castings include controlling vibration, creating stability and easily formulated to meet specific requirements. In the US, the most commonly used classification is ASTM A-48. With Classes of: 20, 30, 40, 60.

Advantages:

• Low cost.
• Good machinability.
• Good dampening capacity.

Disadvantages:

• Low tensile strength.

Ductile Iron

Ductile Iron Castings are unique in that they offer superior flexible and elastic metal qualities that can be incorporated into an array of applications and products for use in multiple industries. May be referred to as nodular iron. Some benefits of ductile iron include resistance to cracking, impact and fatigue resistance. Common classification in the US is ASTM A536-84. With grades of: 60-40-18, 65-45-12, 80-55-06, 100-70-03. There are many other special grades available including Austempered ductile iron.

Advantages:

• Good resistance to cracking
• Good resistance to fatigue
• Good strength characteristics

Disadvantages:

• Higher cost