compressive strength of cast iron as compared to tensile strength
Cast iron The earliest cast-iron artifacts date to the 5th century BC, and were discovered by archaeologists in what is now modern Luhe County, Jiangsu in China. This is based on an analysis of the artifact's microstructures.[2] Because cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required. It is strong under compression, but not under tension. Cast iron was invented in China in the 5th century BC and poured into moulds to make ploughshares and pots as well as weapons and pagodas.[11] Although steel was more desirable, cast iron was cheaper and thus was more commonly used for implements in ancient China, while wrought iron or steel was used for weapons.[2]
Ductility Ductility is a measure of a material's ability to undergo significant plastic deformation before rupture, which may be expressed as percent elongation or percent area reduction from a tensile test. According to Shigley's Mechanical Engineering Design--10th Ed. [1] significant denotes about 5.0 percent elongation (Section 5.3, p. 233). See also Eq. 2-12, p. 50 for definitions of percent elongation and percent area reduction. Ductility is often characterized by the material's ability to be stretched into a wire.