Greenlee 12" Bit Extension wit...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$86.51
$31.95
Greenlee 901-12 12" Bit Extension

Greenlee 12" Bit Extension with 1/4" Hex Shank for Professional Drilling Applications

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Model: 901-12
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$86.51
$31.95
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Greenlee 12" Bit Extension with 1/4" Hex Shank for Professional Drilling Applications

Professional drilling extension for deeper wood boring applications

The Greenlee 12" Bit Extension delivers professional-grade performance for electricians and contractors requiring extended reach in wood boring applications. Featuring a durable 1/4" hex shank design with 9/16" head diameter, this extension tool enables deeper drilling access while maintaining compatibility with holesaw arbors, spade bits, Nail Eater II� bits, electrician's bits, and step bits for versatile job site applications.

Professional Features & Benefits

  • 12" Extension Length: Provides extended reach for boring deeper into wood structures and accessing confined spaces.
  • 1/4" Hex Shank Design: Ensures secure connection and compatibility with standard drill chucks and drivers.
  • 9/16" Head Diameter: Optimized head size delivers reliable bit engagement and transfer of drilling force.
  • Multi-Bit Compatibility: Works with holesaw arbors, spade bits, Nail Eater II� bits, electrician's bits, and step bits for versatile applications.
  • Professional Construction: Built to withstand demanding job site conditions with reliable performance and durability.
  • Compact 1.4 LB Weight: Balanced design reduces operator fatigue during extended drilling operations.

Technical Specifications

  • D Chain: 4
  • Head Diameter: 9/16 IN
  • Hole Diameter: 1/4 IN
  • Material Master Number: 50027069
  • Package Type: Pop
  • Product Length: 12.000 IN
  • Product Size: 1/4 IN Hex Shank
  • Product Weight: 1.400 LB (636.000 GM)

Installation & Operation

  1. Mount the extension securely in the drill chuck, ensuring the 1/4" hex shank is fully seated and tightened.
  2. Connect the appropriate bit type (holesaw arbor, spade bit, Nail Eater II�, electrician's bit, or step bit) to the extension head.
  3. Position the drill assembly at the desired boring location with proper alignment and support.
  4. Configure drill speed and torque settings appropriate for the bit type and wood material being drilled.
  5. Test the extension and bit assembly for secure connection and proper operation before full drilling engagement.
  6. Complete drilling operations following standard safety practices and maintain the extension for continued reliable performance.

Professional Applications

  • Electrical rough-in work requiring deep wood boring access
  • Residential construction and renovation projects
  • Commercial building electrical installations
  • Professional contractor drilling operations
  • Maintenance and repair applications in confined spaces
  • Multi-trade construction projects requiring extended reach

Why Choose Greenlee Quality?

Greenlee delivers professional-grade tools engineered for reliability and durability in demanding electrical and construction applications. This bit extension features robust construction and precise manufacturing to ensure consistent performance and long service life, backed by Greenlee's commitment to professional tool quality and contractor satisfaction.

Manufacturer Resources

Product Specs

D Chain:
4
Head Diameter:
9/16 IN
Hole Diameter:
1/4 IN
Material Master Number:
50027069
Package Type:
Pop
Product Length:
12.000 IN
Product Size:
1/4 IN Hex Shank
Product Weight:
1.400 LB (636.000 GM)

Greenlee 901-12 – Frequently Asked Questions

1) Will a Greenlee 901-12 bit extension fit a standard drill chuck or an impact driver?
The 901-12 extension has a 1/4 inch hex shank, so it seats in a standard three-jaw drill chuck and in any 1/4 inch hex quick-change holder, which is what impact drivers and most cordless drivers take. Seat the hex fully in the chuck and tighten before you put it under load.
2) How much extra reach does the Greenlee 901-12 give me for drilling through studs and joists?
The extension is 12 inches long overall, so it adds roughly a foot of reach ahead of the chuck, minus whatever the bit itself takes up. For electrical rough-in that is enough to get a bit through a stud bay or down a joist line from outside the cavity, and enough to keep the drill body clear when you are boring in a tight space.
3) Does the Greenlee 901-12 bit extension come with a bit, or do I need to order one separately?
The 901-12 is the extension alone. You supply the cutting tool: a holesaw arbor, spade bit, Nail Eater II bit, electrician's bit, or step bit, each with a 1/4 inch hex shank to match the extension's 1/4 inch receiving hole. If you are stocking a rough-in truck, order the extension once and match it to the bit sizes you already run.
4) Is a 9/16 inch extension head going to bind in the hole behind my spade bit?
The head measures 9/16 inch across, so any bit cutting larger than 9/16 inch leaves a hole the extension head passes through freely. Boring with a bit smaller than 9/16 inch is where you get trouble, the head will stop at the face of the wood and you only get bit-length depth, not extension depth. For electrical rough-in, where holes are typically 3/4 inch and up, this is a non-issue.
5) Will a 12 inch bit extension get me through a double top plate or drilled-stacked plates?
Yes for the plate depth itself. A double top plate is about 3 inches of wood, so 12 inches of extension plus the bit clears it with room to spare and keeps the drill out from under the ceiling. Where a 12 inch extension does not help is total bore depth on a long run, that is set by the bit, not the extension.
6) Should I use a bit extension or just buy a longer auger bit?
A 12 inch extension like the 901-12 is the choice when you already own the bits and need reach occasionally, because it works across holesaw arbors, spade bits, Nail Eater II bits, electrician's bits, and step bits from one piece. A long-shank auger is the choice when you bore deep constantly on the same diameter, since a one-piece bit has no joint to flex or loosen. Extensions add a connection point, so they run best at moderate speed with the bit tracking straight.
7) What is the Greenlee part number to order for the 12 inch, 1/4 inch hex bit extension?
Order Greenlee 901-12. That is the 12 inch extension with the 1/4 inch hex shank and the 9/16 inch head. It ships as a single piece on a pop-style card, so there is no kit quantity to specify.
8) How heavy is the Greenlee 901-12 extension on the end of a drill?
1.4 lb, or 636 grams. That is enough weight out past the chuck to notice on overhead boring, so support the drill body rather than letting the extension cantilever, especially with a holesaw arbor on the end.
How fast can I get the Greenlee 901-12 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Greenlee 901-12 come with a warranty?
Absolutely. The Greenlee 901-12 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Greenlee 901-12?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Greenlee 901-12 from ZenSupply?
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