🔍 Key Concepts

• Standard drill bit sizing systems: numbered, fractional, and lettered sizes • Typical contents and size range of a common jobbers drill set used in general shop work • Difference between small precision sets and larger, less common sets

💭 Think About

• Think about which type of drill set you are most likely to see in a basic maintenance shop on board a vessel. • Which size range would cover the most common hole sizes for bolts, screws, and general-purpose work? • Are jobbers sets usually very small specialty sizes, very large heavy drills, or the mid‑range everyday sizes?

✅ Before You Answer

• Identify which option represents the most commonly used, general-purpose drill sizes. • Eliminate any answers that focus on very small precision or very large drills not normally in a standard portable box set. • Confirm which sizing system (numbered, fractional, lettered) is most typical for a basic shipboard drill index.