1/4"-20 UNC-3A × 1/2" Spanner Flat Head Screw
ASTM B21 Grade 464. Machined to the customer's drawing in our Houston shop.
1/4"-20 UNC-3A × 1/2" ASTM B21 Grade 464 Naval Brass Built for excellent corrosion resistance, dependable strength, and demanding marine and industrial applications.
Special socket products are machined from bar where the specification allows, with the socket broached and the threads rolled, or cut where the specification or order allows, then heat treated and plated as the specification requires. Shoulder, low-head, flat-head and set-screw patterns follow ASME B18.3 unless the drawing says otherwise.
About the material: The marine brass — 1 percent tin for seawater resistance — and the ASTM F468 structural brass fastener alloy (F468D). Read the C46400 Naval Brass data page →
