Outside micrometer: outside diameter of ground pin Ø12

What happens in the video

1. 0:00 Outside micrometer: outside diameter of ground pin Ø12
2. 0:04 Close the faces with the ratchet: the sleeve and thimble must read 0.
3. 0:09 Back the spindle off and set ground pin Ø12 between the anvil and the spindle.
4. 0:13 Turn the ratchet to bring the spindle slowly onto the part until the anvil and the spindle both touch it.
5. 0:18 Read while the micrometer is still on the part: 12.00 mm, within 11.97–12.03 mm.

In the course

• Micrometers · The screw and the reading — Read a mechanical micrometer and know where its hundredths come from.
• Micrometers · Checking and setting zero — Check a micrometer’s zero before use and correct for a zero error.

Read the guide

• 
  Reading instrumentsHow to read a micrometerAn outside micrometer reads to 0.01 mm: the spindle thread has a 0.5 mm pitch and the thimble has 50 divisions, so one division is 0.5 / 50 = 0.01 mm.
• 
  Reading instrumentsMicrometer zero check and zero error correctionCheck zero before every use: on a 0–25 mm micrometer close the clean faces gently with the ratchet; on 25–50 mm and larger close on the setting standard (25 mm, 50 mm, 75 mm).
• 
  Reading instrumentsScrew gauge: least count and readingLeast count of a screw gauge = pitch ÷ number of divisions on the circular scale: 1 mm ÷ 100 = 0.01 mm, or 0.5 mm ÷ 50 = 0.01 mm.