Amana Tool offers an array of unique extended life Aluminum titanium nitride (Altin) coated router bits for all your fiberglass application needs. Premium Altin coating provides double the hardness of cutting edges resulting in Quantum increases in productivity, either in terms of speed or longevity, with or without coolant. Coating helps prevent edge failures due from vibration and shock during CNC and manual feed applications, #48054-D, (D) diameter: 1/4, (b) Cutting height: 2-1/8, (D) shank: 1/4, overall length (L): 4, type: drill end48054-d high performance Solid carbide fiberglass and Composite cutting 1/4 dia x 2-1/8 x 1/4 shank Altin coated drill end router bit