🔍 Key Concepts

• What is “pinning” on a file? Think about metal or material particles getting stuck between the teeth of the file. • How pressure on the file affects how material is removed and whether it packs into the teeth. • How different actions (dropping, chalking, cleaning, or pressing) would change the condition of the file’s cutting edges.

💭 Think About

• Which choice would most likely cause small bits of metal or material to be forced and jammed into the file’s teeth instead of being cut away cleanly? • For each option, ask: does this action tend to prevent buildup in the file’s teeth, or does it tend to increase the chance of buildup? • Think about why experienced machinists use chalk on a file—does that normally help avoid or create pinning?

✅ Before You Answer

• Be clear on the definition of pinning: material packed into and stuck in the file teeth. • Identify which listed actions are usually taken to prevent pinning (those options can be ruled out). • Focus on the choice that involves how hard the file is used and how that affects material packing in the teeth.