Midwest Cap Screw, High Strength, 1/4-20 Screw, 2 in Length, Hexagonal Head, NC Thread, Alloy Steel, Grade 5, Zinc Plated. Midwest Cap Screw, High Strength, 1/4-20 Screw, 2 in Length, Hexagonal Head, NC Thread, Alloy Steel, Grade 5, Zinc Plated.