The words âat least 17 years of age and *â*â* under 45 years of ageâ are substituted for the words âwho shall be more than seventeen years of age and *â*â* not more than forty-five years of ageâ.
Steel is cheaper, and brass is more expensive, and not much of a structural material. Brass is a tensile metal, and has a great ability to bend. It is used to make bearings, valves and moving parts, because it does not break easily. Steel, on the contrary, is difficult to cast, and quite difficult to work with in small machines.
Brass is a common useful metal. Here's a look at what brass is made of and information about its chemistry. Answer: Brass is an alloy made primarily of copper and zinc. The proportions of the copper and zinc are varied to yield many different kinds of brass. Basic modern brass is 67% copper and 33% zinc. Lead commonly is added to brass at a concentration of around 2%. The lead addition improves the machinability of brass.