Specially designed for working in hard solid wood. Slow helix, Special grinding angle, improved body shape in order to support the high feed rate, Quick direction changes and deep penetration, #46390, (D) diameter 1/4, (b) Cutting height 7/8, (D) shank 1/4, overall length (L) 2-1/2, B1 9/32, flutes 1, 46390 CNC solid carbide compression spiral for solid wood 1/4 dia x 7/8 x 1/4 inch shank Single flute