Chicago-Latrobe 40576 135° NAS Aircraft Extension Drill 9/32″ HSS Black Oxide

Aircraft Extension Drill 9/32″

The Chicago-Latrobe 40576 is a NAS-type aircraft extension drill built for precision drilling in aviation and maintenance tasks. Its 135-degree split point reduces walking and delivers accurate hole starts in tough alloys. The high-speed steel body with black oxide finish resists wear during extended use. Mechanics and fabricators working on airframe structures will value its reach and rigidity.

Capacity And Drilling Depth

This bit handles a maximum drilling depth of 1 1/8 inches with a 4xD length-to-diameter ratio for deeper access. The 9/32-inch fractional size suits standard rivet and fastener holes in sheet metal and structural components. Material grade HAWA supports high-performance machining in aluminium, titanium and heat-treated steels. It runs out when hole diameters exceed its fixed size or when depths surpass the flute length.

135-Degree Split Point Geometry

The 135-degree point angle with split-point geometry centres the drill without a centre punch, reducing thrust force and heat buildup. Black oxide coating aids chip flow and adds corrosion resistance during prolonged operations. The 28-degree helix angle balances chip evacuation and edge strength for consistent performance. Users needing different point angles, coatings or metric sizes must select alternative tooling.