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Drill America

Drill America 25/64in x 6in Cobalt Aircraft Extension Drill Bit pneumatic accessory

SKU CH-4P77-B9GYT

Cobalt aircraft extension drill bit with heavy-duty split point for deep-hole drilling in tough metals

  • TypeDrill Accessories
  • Cobalt steel resists heat during heavy drilling
  • Split-point tip starts holes without walking
  • 6-inch reach accesses deep or confined work
  • Decimal size .3906 matches precise 25/64 specification

25/64in Cobalt Extension Drill Bit

The Drill America bit is built for reaching deep holes in metal fabrication and aircraft maintenance. Its 6in overall length extends reach through structural members or thick workpieces. Cobalt steel construction resists heat and wear when drilling tough alloys. The heavy-duty split point reduces walking and starts cleanly on contact.

Cobalt steel build and split point

Cobalt steel holds hardness at elevated temperatures during prolonged drilling in stainless or high-strength steels. The split point geometry centres the bit without a centre punch, saving setup time. A 3-3/4in flute length clears chips efficiently over the full depth. The straight shank fits standard drill chucks and pneumatic drill motors.

Highlights

  • Cobalt steel resists heat during heavy drilling
  • Split-point tip starts holes without walking
  • 6-inch reach accesses deep or confined work
  • Decimal size .3906 matches precise 25/64 specification

Specifications

BrandDrill America
TypeDrill Accessories

Questions about this item

What shank size does the 25/64in cobalt aircraft extension drill bit use for pneumatic chucks?

The bit has a 25/64in diameter shank that matches the decimal equivalent .3906, fitting standard pneumatic chucks sized for that dimension.

What clearance is needed to accommodate the 6in overall length of this drill bit?

The bit measures 6in overall with a 3-3/4in flute length, so allow at least 6in of spindle travel and workpiece clearance for full engagement.

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