Greenlee #3 Cobalt HSS Step Dr...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$194.46
$192.81
Greenlee #3 Cobalt HSS Step Drill Bit - 12-Stage Professional Drilling System

Greenlee #3 Cobalt HSS Step Drill Bit - 12-Stage Professional Drilling System

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Model: 34403C
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$194.46
$192.81
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Greenlee #3 Cobalt HSS Step Drill Bit - 12-Stage Professional Drilling System

High-Performance Cobalt Construction for Stainless Steel & Multi-Material Applications

The Greenlee #3 Cobalt HSS Step Drill Bit delivers professional-grade drilling performance with engineered cobalt high-speed steel construction for maximum durability in demanding stainless steel applications. This 12-stage step bit provides versatile drilling capabilities across multiple materials including mild steel, copper, brass, aluminum, fiberglass, plastic, wood, and laminates, making it an essential tool for electrical, HVAC, and general construction professionals.

Professional Features & Benefits

  • Cobalt HSS Construction: Engineered with cobalt high-speed steel material for maximum tool life and superior performance in stainless steel up to 10 gauge thickness.
  • 12-Stage Design: Multiple drilling stages provide precise hole sizing options and eliminate the need for multiple individual drill bits.
  • Multi-Material Capability: Cuts through mild steel, copper, brass, aluminum, fiberglass, plastic, wood, and laminates for versatile job site applications.
  • Stainless Steel Rated: Specifically engineered for drilling stainless steel materials up to 10 gauge, delivering clean, precise holes without material distortion.
  • Professional Grade Quality: Greenlee manufacturing standards ensure consistent performance and reliability in demanding professional environments.
  • USA Manufacturing: Manufactured in the United States with quality materials and precision engineering for long-lasting durability.

Technical Specifications

  • Country Of Origin: United States
  • Number Of Drill Stages: 12
  • Product Type: Cobalt Step Bit

Installation & Operation

  1. Mount the step bit securely in a compatible drill or driver with appropriate chuck capacity and torque settings.
  2. Mark the desired hole location and ensure the work surface is properly secured and supported.
  3. Begin drilling at low speed to establish the pilot hole, then gradually increase speed as appropriate for the material.
  4. Apply steady, consistent pressure while allowing the stepped design to progressively enlarge the hole to the desired diameter.
  5. Clear debris periodically during drilling to maintain cutting efficiency and prevent overheating.
  6. Complete the hole to the required stage marking and verify final diameter before removing the bit.

Professional Applications

  • Electrical panel and enclosure installations requiring precise hole sizing
  • HVAC ductwork and equipment mounting applications
  • Stainless steel fabrication and food service equipment installation
  • Industrial maintenance and repair operations
  • Commercial construction and renovation projects
  • Automotive and transportation industry applications
  • General metalworking and fabrication shops

Why Choose Greenlee Quality?

Greenlee delivers professional-grade tools engineered for the demands of electrical, telecommunications, and construction professionals. This cobalt step bit represents decades of manufacturing expertise with USA-made quality construction, ensuring reliable performance and extended tool life in the most challenging drilling applications across multiple material types.

Manufacturer Resources

Spec Sheet

Product Specs

Country Of Origin:
United States
Number Of Drill Stages:
12
Product Type:
Step Drill Bit
Department:
Electrical
Product Subgroup:
Drill & Driver Bits
Product Group:
Power Tools & Accessories

Greenlee 34403C – Frequently Asked Questions

1) Will a Greenlee 34403C step bit drill stainless steel, or do I need a different bit?
Cobalt high-speed steel is exactly what this one is for. The Greenlee #3 step bit, model 34403C, is built from cobalt HSS and rated for stainless steel up to 10 gauge. It also cuts mild steel, copper, brass, aluminum, fiberglass, plastic, wood, and laminates, so it covers panel and enclosure work and stainless fabrication with the same bit.
2) How many hole sizes does the Greenlee #3 cobalt step bit cut?
Twelve. The #3 is a 12-stage step bit, so one bit covers twelve hole diameters and you step up to the marking you need instead of swapping through a set of individual twist bits.
3) Step bit or hole saw for drilling an electrical enclosure?
For sheet metal in panels, boxes, and enclosures, a step bit is the better tool: it self-pilots, deburrs as it steps, and gives you twelve diameters off one bit. Hole saws make more sense in thicker stock or wood, or where you need a diameter larger than the bit's top step. The Greenlee #3 cobalt bit is aimed squarely at the sheet metal end of that work, including stainless up to 10 gauge.
4) Is the Greenlee 34403C step bit made in the USA?
Yes, the #3 cobalt step bit is manufactured in the United States. That matters on public and institutional jobs with domestic-sourcing requirements on tooling purchases.
5) Can I run the Greenlee #3 cobalt step bit in a cordless drill?
It mounts in any drill or impact-rated driver whose chuck will accept the shank and that can hold the speed down. Start slow to establish the pilot, then bring the speed up to suit the material, keep steady pressure so each step does its work, and clear chips as you go so the cobalt edge does not overheat. Heat is what kills step bits in stainless.
6) What trades actually use a cobalt step bit like the Greenlee #3?
Electricians drilling panels and enclosures, HVAC crews on ductwork and equipment mounts, stainless and food service equipment installers, and MRO and fabrication shops doing industrial repair. The common thread is sheet metal holes in mixed materials where carrying a full twist bit index is not practical.
How fast can I get the Greenlee 34403C 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 34403C come with a warranty?
Absolutely. The Greenlee 34403C 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 34403C?
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 34403C 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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