DRILLCO DRL720A053 - #53 Slow Helix 135degBrand Drillco Product SKU 720A053 Category Drills Size Number Material Solid Carbide Finish Coating Bright Pack Quantity 1 Size 53 Overall Length 1. 1 2 Flute Length 5 8 Description Slow helix 135? split point provides ease of penetration and increases edge strength. Heavy duty web short flute and overall lengths increase strength and rigidity. Ideally suited for drilling difficult materials (up to Rc 60) including nickel alloys chrome alloys steel