 Welcome to an overview of squaring the tool head. In this video, we'll go over the necessary steps to square the tool head to the table on a bridge port mill. The head of the mill has to be square. This is very important. If it isn't square, you won't be able to mill your pieces square and you will drill holes at an angle. Let's go through how to square or tram the tool head. You'll need a table stone, a three-quarter inch wrench, a tramming ring, a finger indicator, and something to hold the indicator. We'll be using a zero-it indicator holder. Begin by making sure the table and the ring are free of burrs, dirt, and chips. Clean the table and tramming ring with a cleaner and then stone the table and tramming ring using the table stone. When stoning the table, make sure you're always using a figure eight pattern. After stoning, wipe off the table and the tramming ring. Put the tramming ring on the table. Clamp the zero-it indicator holder into a drill chuck, collet, or solid holder. Place the indicator into the holder and clamp it. Put the spindle into neutral so that it's easy to turn. Rotate the spindle by hand. Make sure the indicator will stay on the top surface of the tramming ring. You may have to adjust the holder to achieve this. Now bring the table up until you have 10 to 20 thousandths of pressure. Clamp the knee. Loosen the front tool head clamping bolts one at a time and then lightly retighten them to ensure there is some drag. Move the indicator to the three o'clock position as you're looking down at the ring. Zero out the indicator by rotating its face until the zero lines up with the needle. Rotate the spindle until the indicator is at the nine o'clock position and read how far the indicator moves. Divide this number by two. This is how far you'll need to move the head using the swivel bolt. Move in the direction that the needle is moving back toward zero. Once you've moved it, zero out the indicator again and rotate it to the three o'clock position. Take a reading on the indicator. If it's within one thousandth of an inch, you can tighten the front tool head bolts. Check that the head didn't move while you were tightening the bolts. If the indicator reads more than one thousandth of an inch, you'll need to make more adjustments before tightening the front tool head bolts. Always double check your readings on the indicator after tightening the bolts. Once you've tightened the front tool head bolts, relieve the pressure on the swivel bolt. Next, perform the same procedure for the twelve o'clock and the six o'clock positions. This uses the tool head side clamping bolts. Loosen the side tool head clamping bolts one at a time and lightly retighten them to ensure that there is some drag. Rotate the indicator to the six o'clock position and take the indicator reading. Move the head with the swivel bolt until the indicator is back to zero. Once the indicator is at zero, rotate it to the twelve o'clock position and ensure that it's reading within one thousandth of an inch. Tighten the side tool head clamping bolts. Relieve the pressure on the swivel bolt. Check that the indicator is still reading within one thousandth of an inch all the way around the tramming ring. If the reading is less than one thousandth of an inch, then the head is square and you're ready to mount your workpiece. If the reading is more than one thousandth of an inch, you'll need to repeat the prior steps until it reads within one thousandth of an inch all the way around. Once you've determined that the head is square, lower the table. Remove the tramming ring, remove the indicator from the holder and remove the holder from the spindle. You've now finished squaring the head on a bridge port milling machine. You're ready to mill your pieces and drill your holes. You've completed an overview of squaring the tool head.