It takes around 8 to 10 minutes to cook a steak to well done and the internal temperature should be at least 170 F.
A steak that is done and cooked and medium rare should be soft and tender and still fleshy feeling.
When a steak is cooked and done to medium the steak should feel tender but also have some resistance to the meat of the steak.
When a steak is cooked to well done the temperature of the steak internally should reach 170 F and there should be no pink color to the inside of the steak.
If the steak has a little pink it's not well done but it still is safe to eat the steak with some pink color to it.
A steak that is well done and fully cooked is brown in color uniformly throughout the steak and the internal temperature is 170 F.
If you want your steak well done it takes around 8 to 10 minutes to cook the steak to well done.