Greenlee 501761 1/4-20NC Drill...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$18.59
Greenlee 501761 1/4-20NC Drill/Tap Bit, High Speed Steel

Greenlee 501761 1/4-20NC Drill/Tap Bit, High Speed Steel

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Model: 50176161

In Stock (leaves warehouse same day if ordered before 3pm ET)

$18.59
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Greenlee 501761 1/4-20NC Drill/Tap Bit, High Speed Steel

The Greenlee 501761 1/4-20NC Drill/Tap Bit is a combination drill and tap tool built to drill a pilot hole and cut 1/4-20NC threads in a single pass, cutting assembly time for electricians and fabricators. Machined from High Speed Steel, this bit is rated to drill and tap material thickness up to 10 GA in Mild Steel, Copper, Brass, and Aluminum. A Split Point With Web Thinning geometry delivers a self-centering start that resists walking on contact, while the 1/4 IN Quick Change Hex shank allows fast, secure insertion into compatible quick-change drivers and drills for rapid bit swaps in the field or shop.

Key Features

  • Thread Size: 1/4-20NC drill/tap combination creates a pilot hole and cuts matching threads in one operation, eliminating a separate tapping step.
  • Durable Construction: High Speed Steel body provides the hardness and heat resistance needed to withstand repeated drilling and tapping cycles without premature wear.
  • Point Type: Split Point With Web Thinning gives a self-centering start and reduces walking on contact, resulting in cleaner, more precisely located holes.
  • Shank Style: 1/4 IN Quick Change Hex shank allows quick insertion and removal from compatible quick-change chucks and drivers, minimizing downtime between bit changes on the job.
  • Material Compatibility: Rated for use on Mild Steel, Copper, Brass, and Aluminum, making it a versatile choice across electrical and general metalworking applications.
  • Material Thickness: Designed to drill and tap material up to 10 GA in thickness, suitable for panel, enclosure, and bracket fabrication tasks.

Technical Specifications

  • Shank: 1/4 IN Quick Change Hex
  • Country Of Origin: CN
  • Product Material: High Speed Steel
  • Material Thickness: Up to 10 GA
  • Material Type: Mild Steel, Copper, Brass, Aluminum
  • Point Type: Split Point With Web Thinning

Typical Applications

  • Electrical Panel and Enclosure Fabrication
  • Bracket and Bus Bar Drilling and Tapping
  • Sheet Metal Assembly on Mild Steel, Copper, Brass, and Aluminum
  • Field and Shop Threaded Hole Creation for Mounting Hardware

Why Greenlee?

Greenlee builds tools for professionals who demand reliable performance on the job site. The 501761 Drill/Tap Bit combines High Speed Steel construction with a Split Point With Web Thinning design and a Quick Change Hex shank to deliver consistent, accurate drilling and tapping across common electrical and metalworking materials including Mild Steel, Copper, Brass, and Aluminum. It's a practical, time-saving addition to any electrician's or fabricator's tool kit, reducing separate drilling and tapping steps into one efficient operation.

Manufacturer Resources

Spec Sheet

Product Specs

Shank:
1/4 IN Quick Change Hex
Product Type:
Drill Tap Bit
Department:
Electrical
Product Material:
High Speed Steel
Material Thickness:
Up to 10 GA
Material Type:
Mild Steel, Copper, Brass, Aluminum
Point Type:
Split Point With Web Thinning
Product Subgroup:
Tap Tools & Deburrers
Product Group:
Hand Tools

Greenlee 50176161 – Frequently Asked Questions

1) What thread sizes does the Greenlee drill/tap bit come in?
Seven thread sizes are offered: 6-32NC, 8-32NC, 10-24NC, 10-32NF, 1/4-20NC, 5/16-18NC and 3/8-16NC. Order by part number, for example 50176161 for 1/4-20NC, 50116274 for 5/16-18NC and 50116282 for 3/8-16NC. Note 10-32NF is the only fine thread in the group; everything else is coarse.
2) How thick a panel can a Greenlee drill/tap bit handle?
Up to 10 gauge material. That covers most enclosure walls, panel backplates, struts and mounting brackets. Anything heavier than 10 GA needs a conventional drill bit plus a separate tap, because the tap section on this tool is only long enough to thread through that thickness.
3) Can I use this drill/tap bit on stainless steel?
No. The rated materials are mild steel, copper, brass and aluminum. Stainless is outside what this High Speed Steel drill/tap is rated for, and running it in stainless work-hardens the hole and will strip the tap flutes. Use a cobalt tap and proper cutting fluid for stainless.
4) Will this fit an impact driver chuck?
The shank is a 1/4 inch quick change hex, so it drops straight into the 1/4 inch hex collet on a standard impact driver or quick-change drill chuck. Tapping wants controlled, slower rotation though, so a variable speed drill or drill/driver gives you better thread quality than hammering it with impact.
5) Do I need to drill a pilot hole first?
No, that's the point of the tool. The bit drills the pilot and cuts the threads in one pass, so a separate drill bit and tap step is eliminated. The split point with web thinning starts self-centering, so it won't walk across sheet metal when you set it on the layout mark.
6) Which size do I pick for 1/4-20 machine screws in an enclosure backplate?
The 1/4-20NC version, part number 50176161. It cuts the 1/4-20 coarse thread directly, so the hole takes a standard 1/4-20 bolt or machine screw with no tapping step. If you're mounting lighter device brackets, 8-32NC (50176129) and 10-24NC (50176137) are the common small-screw sizes.
7) Is this suitable for tapping copper bus bar?
Yes, copper is one of the rated materials, along with brass, aluminum and mild steel, so tapping mounting holes in bus bar and copper grounding hardware is within its range. Keep the stock at 10 gauge or less. Copper is gummy, so back the bit out to clear chips rather than forcing it through.
8) What is the difference between the 10-24NC and 10-32NF drill/tap bits?
Same nominal #10 screw diameter, different thread pitch. 10-24NC (part 50176137) is the coarse thread, 10-32NF (part 50176145) is the fine thread. Fine threads are what most electrical enclosure and device screws use, so match the bit to the screw you're installing, not just the screw diameter.
How fast can I get the Greenlee 50176161 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 50176161 come with a warranty?
Absolutely. The Greenlee 50176161 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 50176161?
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 50176161 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
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