Hertel 912C 3/8 in Cobalt Straw 12 in OAL Aircraft Extension Drill Bit

This is a new Hertel 912C series 3/8 in cobalt (M42 HSS-Co) aircraft extension drill bit featuring a 135° split point, spiral (helical) flute geometry, and a straw-colored finish from the cobalt alloy — no additional coating applied. The 12 in overall length (OAL) with a 3-5/8 in flute length provides deep-reach access for drilling in confined or deep-cavity applications typical of aerospace, automotive, and structural fabrication work where standard-length drills cannot reach. The 135° split point self-centers on contact, eliminating the need for a pilot hole and significantly reducing walking on curved or irregular surfaces. The straight shank is compatible with standard drill chucks and quick-change extension adapters. M42 cobalt construction delivers increased red hardness and heat resistance compared to M2 HSS, making this drill well-suited for harder alloys including stainless steel, titanium, and high-strength structural steels.

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