Knowledge

The mechanical properties of a material indicate how it responds under specific stresses, which helps to determine its suitability for different applications. Specifications are set by organizations such as the American Society for Testing and Materials (ASTM) so that users can purchase materials with confidence that they meet the requirements for their application. The most commonly used cast gray iron specification is ASTM A48.

In order to qualify cast products according to their specifications, a standard practice is to cast a test bar along with the engineered castings. The ASTM tests are then applied to this test bar and the results are used to qualify the entire batch of castings.

Specifications are also important when welding cast iron parts together. The weld must meet or exceed the mechanical properties of the material being welded together—otherwise, fractures and failures can occur.

A few common mechanical properties for cast iron include:

• Hardness – material’s resistance to abrasion and indentation
• Toughness – material’s ability to absorb energy
• Ductility – material’s ability to deform without fracture
• Elasticity – material’s ability to return to its original dimensions after it has been deformed
• Malleability – material’s ability to deform under compression without rupturing
• Tensile strength – the greatest longitudinal stress a material can bear without tearing apart
• Fatigue strength – the highest stress that a material can withstand for a given number of cycles without breaking

	BRINELL HARDNESS	TENSILE STRENGTH	MODULUS OF ELASTICITY	% ELONGATION (IN 50 MM)
Gray iron class 25	187	29.9 ksi	16.1 Msi	/
Gray iron class 40	235	41.9 ksi	18.2 Msi	/
Ductile iron grade 60-40-18	130-170	60 ksi	24.5 Msi	/
Ductile iron grade 129-90-02	240-300	120 ksi	25.5 Msi	/
CGI grade 250	179 max	36.2 ksi min	/	3
CGI grade 450	207-269	65.2 ksi min	/	1

Vigor has many years of experience and technical reserves in cast iron products, and our technical engineers can provide you with the most professional technical support in the first time. During the production process, Vigor's QC team will give feedback to our customers on the production progress as soon as possible to ensure that the goods can be delivered to our customers smoothly. Vigor always insists on providing our customers with the best quality products and services to ensure that customers and Vigor win-win together. If you are interested in Vigor's cast iron products or other cast products, please do not hesitate to contact us.