|Item Weight||12 ounces|
|Product Dimensions||10 x 7.6 x 1.2 inches|
|California residents||Click here for Proposition 65 warning|
|Item model number||CO18|
|Item Package Quantity||1|
|Warranty Description||1 Year|
Bosch CO18 18-Piece Plastic Cobalt Drill Bit Set
We don't know when or if this item will be back in stock.
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- Withstands high-temperature applications for extended periods of time (up to 1,100 degrees F)
- Rigid, thick web design adds stability to bit in tough applications
- Surface hardened to penetrate tough abrasive materials
- Available in jobber length, full shank
- Best used for drilling into light-gauge metal, high-carbon steel, aluminum and ally steel, cast iron, stainless steel and titanium
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From the manufacturer
Withstands high temperature
Withstands high-temperature applications for extended periods of time (up to 1,100°F)
4X the lifespan of standard metal drill bits
Surface hardened to penetrate tough abrasive materials
Available in jobber length, full shank
Black Oxide for general purpose drilling
(Also available at Impact Tough range)
Titanium for heavy duty repetitive drilling
(Also available at Impact Tough range)
Cobalt for heavy duty drilling in extremely hard or abrasive materials
|Drill Bit Type||Cobalt||Cobalt||Black Oxide||Black Oxide||Titanium Drill Bit||Titanium Drill Bits|
|# of Pieces||14||21||21||29||21||29|
Bosch cobalt drill bits are specially designed for drilling in hard steel. Thick web helix delivers fast material removal combined with increased durability for maximum efficiency and performance. Each bit is manufactured to exacting specifications. Bits 1/8 In. and larger feature a split point that starts on contact with no walking or skating, eliminating the need for a center punch.
These Bosch cobalt drill bits offer superior heat resistance, plus a rigid thick web design for drilling in extremely hard or abrasive materials such as treated stainless steel (precipitation-hardened), cast iron and titanium.
What's in the Box
- 1/16-inch bit (2)
- 5/64-inch bit (2)
- 3/32-inch bit
- 7/64-inch bit (2)
- 1/8-inch bit (2)
- 9/64-inch bit
- 5/32-inch bit
- 11/64-inch bit
- 3/16-inch bit
- 7/32-inch bit
- 1/4-inch bit
- 5/16-inch bit
- 3/8-inch bit
- 1/2-inch bit
- plastic case
Top Customer Reviews
I was VERY impressed.
Five stars and two thumbs up!!!!
This 18-piece set has bits from 1/16" to 1/2", which are the most common sizes I use on a daily basis. My set is a couple of years old and the plastic index case is still intact and all in one piece which is an achievement, since I find that with regular use, the plastic cases of my other drill bit sets either snap at the hinge or latch. Overall, for the price I paid here on Amazon, I think this set of Bosch cobalt bits was a good value and would have no problem recommending it.
These bits are a must have for low rpm drilling of hardened steel. You need to go slow with oil feed, (you can do with a spray bottle of oil yourself), and preferably you should use a drill press. These also work well with wood, but you will need to go in and out and blow the dust out.
I've found the best way to resharpen these are on diamond lapidary machines with water feed. I can go free hand easily, and with a little practice I get it right on the first time. Sometimes though the contact angles are wrong, and they 'dance' on steel. Or also the way you grind can effect the size of the hole. It's best to test your resharpening on a piece of wood first.
That being said, if you can resharpen these the extra cost is really not important at all for CO bits, and also this set is extremely cheap, almost the same as any of the cheap 'titanium' coated or 'hss' advertised bits on the market. CO HSS is the best bit in my opinion as long as you have the tools to resharpen them properly.
If you just have a grinder, or throw away your bits, and your only drilling wood, then other bits will be suitable.
Most Recent Customer Reviews
They don't last as long as I expected. they burn out after drilling a dozen of holes in 1/8" annealed stainless steel.Read more