If you do not have a thermometer to test the internal temperature of your beef steak, you can use the finger test to get an approximate sense of how done the meat is cooked. If you have read the information on The Science of a Great Steak located here, then you will know that certain changes to the meat take place as heat is applied. The finger test allows you to simulate the different tenderness (or lack of) for a beef steak to determine where the beef steak is in the cooking process.
In the images below, you will notice that by using different fingers pressed against your thumb, the area that is being depressed by the single finger on the palm of the hand will feel different. A great way to feel the changes is to keep the finger pressed in the palm of your hand as indicated in the photo for “rare” and switch from finger to finger.
To test your steak, remove it from the grill and place it on a flat surface such as a cutting board or plate. Press down on the steak and compare it to the feeling when you pressed down on your hand. It is actually pretty simple and fairly accurate in most cases.