<Tr> <Td_colspan="2"> Beef Cuts (American terminology) </Td> </Tr> <Tr> <Th> Type </Th> <Td> Short loin and tenderloin cut of beef </Td> </Tr> <P> The T - bone and porterhouse are steaks of beef cut from the short loin (called the sirloin in Commonwealth countries). Both steaks include a "T - shaped" bone with meat on each side . Porterhouse steaks are cut from the rear end of the short loin and thus include more tenderloin steak, along with (on the other side of the bone) a large strip steak . T - bone steaks are cut closer to the front, and contain a smaller section of tenderloin . The smaller portion of a T - bone, when sold alone, is known as a filet mignon, especially if it's cut from the small forward end of the tenderloin . </P> <P> There is little agreement among experts on how large the tenderloin must be to differentiate a T - bone steak from porterhouse . The U.S. Department of Agriculture's Institutional Meat Purchase Specifications state that the tenderloin of a porterhouse must be at least 1.25 inches (32 mm) thick at its widest, while that of a T - bone must be at least 0.5 inches (13 mm). However, steaks with a large tenderloin are often called a "T - bone" in restaurants and steakhouses despite technically being porterhouse . </P>

Where does t-bone steak come from on a cow