3/8"-16 Hex Cap Screws

3/8-16 Hex Cap Screws in all available lengths, grades, materials, and finishes.

3/8-16 Thread Specifications

• Nominal diameter: 0.375"
• Threads per inch: 16
• Tap drill (75% thread): 5/16" (0.3125")
• Clearance hole (close fit): 25/64" (0.391")
• Clearance hole (free fit): 13/32" (0.406")

To thread a 3/8-16 hole, drill with a 5/16" (0.3125") tap drill for a standard 75% thread. For a clearance hole that the 3/8-16 screw passes through, use 25/64" (0.391") for a close fit or 13/32" (0.406") for a free fit. Pair with a matching 3/8-16 nut or tapped hole.