🔍 Key Concepts

• Reading machine drawing thread callouts such as 1 - 8 NC - LH • Difference between right-hand and left-hand threads • Relationship between the number before the dash and thread diameter (inches) in National Coarse (NC) threads

💭 Think About

• Look at the text next to the threaded portion in the illustration—what exact thread designation is written there? • In that designation, which part tells you the thread diameter, and which part tells you whether it is left-hand or right-hand? • Compare what you read on the drawing with each answer choice: which options match both the diameter and the hand of the thread?

✅ Before You Answer

• Identify and interpret the full printed callout next to the threads (e.g., 1 - 8 NC - LH or similar). • Confirm whether the drawing specifically indicates LH (left-hand) or RH (right-hand)**—don’t assume from appearance alone. • Match the first number in the callout to either 1 inch or 1/8 inch to eliminate the wrong diameter choices.