🔍 Key Concepts

• How to read a 0-1 inch outside micrometer (sleeve/main scale + thimble scale). • Each numbered line on the sleeve usually represents 0.100 inch, and each small division 0.025 inch. • Each division on the thimble commonly equals 0.001 inch; the 0.0005 readings are halfway between marks.

💭 Think About

• First, determine how many full 0.100 inch increments are clearly exposed on the sleeve in figure D, then add any extra 0.025-inch divisions that are also fully visible. • Next, look at the line on the thimble that lines up exactly with the horizontal reference line on the sleeve — how many thousandths (0.001) does that add? • Compare whether the sleeve reading is closer to 0.47 inch or 0.48 inch, then decide if the thimble adds .0000, .0005, .0010, or .0015 to reach one of the choices.

✅ Before You Answer

• Be certain which sleeve mark is the last fully visible line to the left of the thimble edge; do not count a partially covered mark. • Confirm how many 0.025-inch increments beyond the last 0.100 marking are visible on the sleeve. • Verify exactly which thimble line is in perfect alignment with the sleeve’s horizontal reference line to decide between .471 vs .481 and .0 vs .5 thousandths.