A semifinished, cogged, hot-rolled, or continuous-cast metal product of uniform section, usually rectangular with radiused corners. Billets are relatively larger than bars. See A semifinished product of square, rectangular, or even round cross section, hot rolled, or forged. For steel, the width of a bloom is not more than twice the thickness, and the cross sectional area is usually not less than about 36 sq. in. No invariable rule prevails for distinguishing between blooms and billets; the terms are frequently used interchangeably.... More.