The most common type of chain used in a mechanical drive system is the ______ chain.

• A. Leaf
• B. Roller
• C. Bushing
• D. Silent

Answer: (B)

Power is transmitted in chains by rolling contact with the sprocket teeth, which reduces friction and wear. This is why the roller chain is the standard choice: its rollers roll over the sprocket, allowing smooth, efficient power transfer even at high speeds and loads. Roller chains are strong, durable, and easy to manufacture and mate with a wide range of sprockets, making them versatile for most mechanical drives. Other chains exist for special cases—leaf chains are heavier and used in lifting, bushing chains rely on sliding contact and wear faster, and silent chains are quieter but more specialized and costly—so they’re not as universally used as roller chains.