For threaded steel rods or eye bolts, the pilot hole should be relative to the hardware?

• A. Slightly smaller than hardware
• B. Slightly larger than hardware (no more than 1/8 inch)
• C. Equal to hardware
• D. Much larger than hardware

Answer: (B)

When you install threaded steel rods or eye bolts in wood, the pilot hole should give just enough clearance so the hardware can pass through smoothly and seat properly without forcing the wood to split or bind. Drilling a hole that is slightly larger than the hardware lets the threads cut into the wood with reduced friction, accommodates minor misalignment, and accommodates wood movement from moisture changes over time. Keeping the hole only a bit larger (no more than about 1/8 inch) preserves most of the wood’s grip on the fastener, maintaining strength and pull-out resistance. If the hole were smaller, the hardware would bite into the wood, increasing the risk of splitting and making installation difficult. If the hole were the same size or much larger, the fastener wouldn’t seat firmly and the load would be poorly transferred, reducing grip or increasing movement under load.