12 pieces 9/32 In. x 4-1/4 In. Cobalt Drill Bit

Model: CO4145
Actual Product may vary from the item shown
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 and features a split point that starts on contact with no walking or skating, eliminating the need for a center punch.
Benefits: CO4145 12 pieces 9/32 In. x 4-1/4 In. Cobalt Drill Bit
  • Withstands high-temperature applications for extended periods of time (up to 1,100°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
Specifications: CO4145 12 pieces 9/32 In. x 4-1/4 In. Cobalt Drill Bit
Overall Length4-1/4"
Quantity6 (bulk)
Shank Diameter0.2812
*Note1/64” – 7/64”: 118° point; 1/8” and larger; 135° point; three flat shank 3/16” and larger
View More Sizes
Item #ReviewsDiameterOverall LengthQuantityShank Diameter 
CO215313/32"5-1/4"1 (carded)0.4062
CO215225/64"5-1/8"1 (carded)0.3906
CO21513/8"5"1 (carded)0.375
CO215427/64"5-3/8"1 (carded)0.4218
CO215715/32"5-3/4"1 (carded)0.4687
CO215629/64"5-5/8"1 (carded)0.4531
CO21557/16"5-1/2"1 (carded)0.4375
CO215023/64"4-7/8"1 (carded)0.3593
CO21459/32"4-1/4"1 (carded)0.2812
CO214417/64"4-1/8"1 (carded)0.2656
CO21431/4"4"1 (carded)0.25
CO214619/64"4-3/8"1 (carded)0.2968
CO214911/32"4-3/4"1 (carded)0.3437
CO214821/64"4-5/8"1 (carded)0.3281
CO21475/16"4-1/2"1 (carded)0.3125
CO213811/64"3-1/4"1 (carded)0.1718
CO21375/32"3-1/8"1 (carded)0.15625
CO21369/64"2-7/8"1 (carded)0.1406
CO21393/16"3-1/2"1 (carded)0.1875
CO214215/64"3-7/8"1 (carded)0.2343
CO21417/32"3-3/4"1 (carded)0.2187
CO214013/64"3-5/8"1 (carded)0.2031
CO21351/8"2-3/4"1 (carded)0.125
CO41281/64"3/4"12 (bulk)0.0156
CO21591/2"6"1 (carded)0.5
CO215831/64"5-7/8"1 (carded)0.4843
CO21311/16"1-7/8"1 (carded)0.0625
CO21347/64"2-5/8"1 (carded)0.1093
CO21333/32"2-1/4"1 (carded)0.0937
CO21325/64"2"1 (carded)0.0781
CO41431/4"4"12 (bulk)0.25
CO41557/16"5-1/2"6 (bulk)0.4375
CO415427/64"5-3/8"6 (bulk)0.4218
CO415313/32"5-1/4"6 (bulk)0.4062
CO415629/64"5-5/8"6 (bulk)0.4531
CO41591/2"6"6 (bulk)0.5
CO415831/64"5-7/8"6 (bulk)0.4843
CO415715/32"5-3/4"6 (bulk)0.4687
CO415225/64"5-1/8"6 (bulk)0.3906
CO41475/16"4-1/2"6 (bulk)0.3125
CO414619/64"4-3/8"6 (bulk)0.2968
CO414821/64"4-5/8"6 (bulk)0.3281
CO41513/8"5"6 (bulk)0.375
CO415023/64"4-7/8"6 (bulk)0.3593
CO414911/32"4-3/4"6 (bulk)0.3437
CO413811/64"3-1/4"12 (bulk)0.1718
CO41375/32"3-1/8"12 (bulk)0.15625
CO41369/64"2-7/8"12 (bulk)0.1406
CO41393/16"3-1/2"12 (bulk)0.1875
CO414215/64"3-7/8"12 (bulk)0.2343
CO41417/32"3-3/4"12 (bulk)0.2187
CO414013/64"3-5/8"12 (bulk)0.2031
CO41351/8"2-3/4"12 (bulk)0.125
CO41303/64"1-3/4"12 (bulk)0.0468
CO41291/32"1-3/8"12 (bulk)0.0312
CO414417/64"4-1/8"6 (bulk)0.2656
CO41311/16"1-7/8"12 (bulk)0.0625
CO41347/64"2-5/8"12 (bulk)0.1093
CO41333/32"2-1/4"12 (bulk)0.0937
CO41325/64"2"12 (bulk)0.0781

Reviews: CO4145 12 pieces 9/32 In. x 4-1/4 In. Cobalt Drill Bit

Support: CO4145 12 pieces 9/32 In. x 4-1/4 In. Cobalt Drill Bit
Customer ServiceCustomer Support

Have a tool, accessory, application or service question? Call us at 1-877-267-2499 or visit Frequenty Asked Questions.

PartsOrder Spare Parts

Order your genuine Bosch parts here.

Additional Information: Cobalt Drill Bits
PDFBosch Metal Drilling Selection Chart

For tool, accessory, application, or service questions, please contact 1-877-Bosch99 (267-2499).

Cobalt Drill Bits


Cobalt Drill Bits