Material's ability to reduce weight and improve performance encourages growth The use of bar steel in crankshafts will increase by as much as 50 percent, from 40 to 60 percent of the market share, by mid-2002 because of the material's capability to improve engine performance and reduce weight, at economical costs, according to a recent study by American Iron and Steel Institute (AISI) Bar and Rod Market Development Group (BRMDG). This growth would be at the expense of cast iron, which currently possesses 60 percent of the crankshaft market.