The flat iron steak is a cut of steak from the shoulder of a steer, also known as the Teres Major. Whole, this muscle is known as Infraspinatus, and one may see this displayed in some butcher shops and meat markets as a "top blade" roast. Steaks that are cross cut from this muscle are called top blade steaks or patio steaks. As a whole cut of meat it usually weighs around 2 to 3 lbs, is located adjacent to the heart of the shoulder clod, under the seven bone. The entire top blade usually yields 4 steaks, between 8 to 12oz. each.
Restaurants, particularly upscale, have recently begun serving flat iron steaks on their menus. Especially popular are flat irons from Wagyu beef, as a way for chefs to offer more affordable and profitable dishes featuring Wagyu or Kobe beef. In the normal grades, marinade is required to achieve tenderness on par with more expensive cuts, such as ribeye or strip steak.