Depth Micrometer

• 1). Rest the micrometer's base on a flat reference surface. Leave the hole in the center of the micrometer uncovered so that the measuring rod has room of exit the body of the micrometer.
  
  
• 2). Rotate the friction thimble -- the rotating knob at the top of the depth micrometer -- clockwise to lower the measuring rod. Continue lowering the rod until it comes into contact with the surface you're measuring. Brown & Sharpe friction thimbles continue rotating once the measuring rod contacts something, but they no longer apply force to the lowering spindle, so do not worry about applying too much pressure to the micrometer.
  
  
• 3). Lock the micrometer to preserve the depth setting. Rotate the black ring on the micrometer clockwise.
  
  
• 4). Remove the depth micrometer from the object. Read the micrometer's display to determine the distance between the reference base and the rod's contact surface.
  
  

Outside Micrometer

• 1). Rotate the friction thimble counterclockwise to open the micrometer.
  
  
• 2). Settle the object being measured onto the micrometer's stationary anvil. Hold the object in place as you use the micrometer.
  
  
• 3). Rotate the friction thimble clockwise to lower the spindle into the object being measured. As noted for the depth micrometer, Brown & Sharpe friction thimbles continue rotating once the measuring rod contacts something, but they no longer apply force to the lowering spindle. However, some people convert their B&S micrometers to remove this feature. Stop rotating the thimble if the micrometer continues to apply downward pressure to the spindle, once the object being measured is contacted.
  
  
• 4). Point the locking nut/lever toward the thimble. Feel for the lock tightening inside.
  
  
• 5). Read the object's thickness on the display on the side of the micrometer.
  
  

INTRIMIK Internal Micrometers

• 1). Rotate the thimble to the left to retract the three spindles.
  
  
• 2). Lower the INTRIMIK into a tube or bore. Center the micrometer in the tube as well as possible.
  
  
• 3). Rotate the thimble to the right to extend the micrometer's spindles. Adjust the positioning of the micrometer inside the tube as necessary. Continue extending the spindles until all three spindle faces gently contact the internal surface of the tube. The thimbles on INTRIMIK micrometers do not feature "friction thimble" technology, so stop turning the thimble once all three spindles touch the sides of the tube to avoid possibly damaging the micrometer and the part.
  
  
• 4). Read the measurement on the scale along the side of the INTRIMIK micrometer. If you can't read the scale while the micrometer is inside the tube, remove your fingers from the thimble and gently slide the micrometer out of the tube. Avoid jostling the spindles as you remove the micrometer.