These solid aluminum nails can be hammered into pre-drilled holes to fasten tackless strip or metal moldings down onto concrete subfloors, or onto tile or stone when necessary. The semi-square body compresses and holds against the walls of a pre-drilled ¹/₈” hole. For carbide or masonry drill bits used to drill the ³/₁₆” holes for these fasteners, see our No. 224 ³/₁₆” Solid Carbide Drill with No. 226 ³/₁₆” Hexagon Adaptor. Fastener dimensions: ³/₁₆” dia. x ⁷/₈” long. Hole size: ³/₁₆” x 1″.