SKU: 36471613045

Bosch CO21B 21 Piece Cobalt M42 Metal Drill Bit Set for Stainless Steel Cast Iron and Titanium High Heat Resistant 135 Degree Split Point

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Description

Bosch CO21B 21 Piece Cobalt M42 Metal Drill Bit Set for Stainless Steel Cast Iron and Titanium High Heat Resistant 135 Degree Split PointUnrivaled Durability in Hard Metals: Engineered with 8% Cobalt for 10X Longer Life The Bosch CO21B 21 Piece Cobalt M42 Drill Bit Set is the definitive choice for professionals facing the toughest drilling challenges. Engineered with an upgraded M42 alloy containing 8% cobalt, these "hard core" bits are specifically designed to deliver 10X the service life of standard bits while withstanding extreme heat in high temperature applications. Whether you

Unrivaled Durability in Hard Metals: Engineered with 8% Cobalt for 10X Longer Life

The Bosch CO21B 21-Piece Cobalt M42 Drill Bit Set is the definitive choice for professionals facing the toughest drilling challenges. Engineered with an upgraded M42 alloy containing 8% cobalt, these "hard-core" bits are specifically designed to deliver 10X the service life of standard bits while withstanding extreme heat in high-temperature applications. Whether you are drilling through stainless steel, cast iron, or titanium, the thick web-helix design provides superior stability and rapid material removal, ensuring precision and efficiency on every job.

Designed for maximum jobsite performance, these bits feature a specialized 135-degree split point on all sizes 1/8" and larger, allowing for immediate, "no-skate" starts without the need for a center punch. To further increase productivity, bits 3/16" and larger are equipped with a three-flat shank that provides a secure grip in the drill chuck, effectively eliminating bit slippage during high-torque tasks. From light-gauge aluminum to abrasive hardened metals, this comprehensive set provides the specialized tip geometry and heat resistance required for professional-grade results.

Key Features

  • Upgraded M42 Alloy: Formulated with 8% cobalt to provide 10X life versus standard drill bits.
  • Extreme Heat Resistance: Engineered to withstand high-temperature applications for extended periods without dulling.
  • Thick Web-Helix Design: Increases structural stability and provides fast material removal in tough materials.
  • No-Skate Split Point: Bits 1/8" and larger feature a split point for accurate starts without a center punch.
  • Secure Three-Flat Shank: Bits 3/16" and larger feature three flats on the shank to prevent bit slippage in the chuck.
  • Hardened Surface: Specifically designed to penetrate hardened surfaces including stainless steel, titanium, and cast iron.

What's Included

  • (2) 1/16", (2) 5/64", (1) 3/32", (1) 7/64" Cobalt Bits
  • (2) 1/8", (1) 9/64", (1) 5/32", (1) 11/64" Cobalt Bits
  • (2) 3/16", (1) 13/64", (1) 7/32", (1) 15/64" Cobalt Bits
  • (2) 1/4", (1) 5/16", (1) 3/8", (1) 1/2" Cobalt Bits
  • (1) Rugged Storage Case

Specifications

Brand Bosch
Model Number CO21B
Bit Material M42 Cobalt Alloy (8% Cobalt)
Bit Type Twist / Jobber Length
Total Piece Count 21
Tip Geometry 135-Degree Split Point
Shank Design Three-Flat (3/16" and larger)
Weight 1.19 lbs
Compatible Materials Stainless Steel, Cast Iron, Titanium, Aluminum
Product Condition New

Pro-Tip: When drilling into hard metals like stainless steel with cobalt bits, use a slower drill speed and apply steady pressure. This technique, combined with the 8% cobalt alloy, minimizes heat buildup and ensures the longest possible cutting life for your bits.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 36471613045

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Claire
Fort Morgan, US
★★★★★ 5
Beautiful bargain bookcase
Industrial, discreet but stylish. Looks so good!! Shelves aren’t super high quality but what do you expect??
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 25, 2024
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Alan Robertson
Whiting, US
★★★★★ 5
Quick and easy - nice pipe kit.
Size: 4-Tier (Not included planks)
Pair these with some shelving boards from your local big box store, and you're in business. These look nice, and are easy to assemble. I had them up and on the wall in about 90 minutes.
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Reviewed in the United States on January 7, 2026
D
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Dora
Massapequa, US
★★★★★ 5
Sturdy, Be mindful if a few things in advance
Size: 5-Tier (Not included planks), Size: 5-Tier (Not included planks)
Good quality. The black pipe compliments our decorating style so we are over all pleased. Be mindful of the following: - Needs a little bit of expertise in making sure all the flanges line up and are level/plumb. - Even if/when you pre assemble tubing according to printed instructions, the shelving won't line up and some connection parts will have to be loosened to line up. - I consider us (me & the hubs) little above average when it comes to DIY but this took some figuring out and cooperation during installation because we decided to align the holes on the flanges up with our studs to enforce the holding strength (for weight of books and family photo albums/picture boxes). This choice was prompted by the poor quality of plastic drywall anchors included with the product. Now that I have installed one, I will customize next time with more height (to accommodate taller children's books that don't fit the current set up) and a bit deeper (to accommodate a 12 inch shelf/wood insert). Aesthetically, it will not accommodate a book taller than about 9 inches. Our photo albums range up to 15 inches and because the shelving depth from back wall to front of wood shelf is about 12 inches, it hangs over the front too much to look balanced. With the current set up, I'm limited with what can be placed on the shelves - size wise. While this does not have anything to do with the quality of the product, you may not know to consider these aspects in advance so thats why I include it in my review.
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Reviewed in the United States on July 13, 2021
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Nest and Tress
West Palm Beach, US
★★★★★ 5
A Solid, Stylish Solution!
Size: 4-Tier (Not included planks)
I use this industrial pipe shelf setup in my salon to display and organize products, and it’s been a great fit. The hardware is sturdy and gives a clean, rustic vibe that works well with my space. It was easy to install, and I added my own boards to customize the look. The open design makes it easy for clients to see what’s available, and it’s held up well with daily use. A solid, stylish solution for keeping things neat and accessible.
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Reviewed in the United States on November 14, 2025
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John crow
New York, US
★★★★★ 4
Good quality
Size: 2Pack of 5 Tier (Not included planks)
Love this very easy to assemble the pipes are sturdy
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Reviewed in the United States on July 17, 2025

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