What is the difference between 304 and 430

A large majority of the cost of any metal is the price of each individual element that is used in the composition. As the cost of alloys changes daily on the global market, this can have a large impact on the price fluctuations. 304 is generally more expensive than 430 because of the chemical composition. Notably, 304 contains between 8 – 10.5% nickel whereas 430 contains 0%. The inclusion of nickel in 304 makes the metal more corrosion resistant than 430 however it is an expensive element which is one of the main reasons for the difference in cost between the 2.

Although 304 is an austenitic grade it can still display magnetic properties after cold working. A very good example of this is the magnetism along the cut edge of any austenitic grade is more noticeable than along any non worked surface.
430 on the other hand is a ferritic grade which makes it very magnetic.
Although there is a difference in the magnetism between the 2 grades, it should be noted that not all magnetic grades are 430 and not all non magnetic grades are 304.