1/2"-20 Flat Head Cap Screws

1/2-20 Flat Head Socket Cap Screws in all available lengths, grades, materials, and finishes. This collection covers every 1/2-20 option in stock — use the filters to narrow by length, grade, material, and finish.

1/2-20 Thread Specifications

• Nominal diameter: 0.5"
• Threads per inch: 20
• Tap drill (75% thread): 29/64" (0.453")
• Clearance hole (close fit): 33/64" (0.516")
• Clearance hole (free fit): 17/32" (0.531")

To thread a 1/2-20 hole, drill with a 29/64" (0.453") tap drill for a standard 75% thread. For a clearance hole that the 1/2-20 screw passes through, use 33/64" (0.516") for a close fit or 17/32" (0.531") for a free fit. Pair with a matching 1/2-20 nut or tapped hole.

Orders before 12 PM ET ship same day.