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 ¹/₈” holes for these fasteners, see our No. 223 ¹/₈” Solid Carbide Drill with No. 225 ¹/₈” Hexagon Adaptor. Fastener dimensions: ¹/₈” dia. x ⁷/₈” long. Hole size: ¹/₈” x 1″.