48-89-2321 Thunderbolt Cobalt Drill Bit, 3/8 In.

The Milwaukee 48-89-2321 Thunderbolt Cobalt Drill Bit is engineered for demanding drilling tasks in hard metals, including stainless steel and other high-strength materials. This 3/8-inch jobber bit delivers consistent performance even under the extreme heat generated during heavy-duty drilling, making it an ideal choice for both cordless and corded drill applications where precision and durability matter.

Built with cobalt material and Milwaukee's RED HELIX design, this twist flute drill bit provides up to 10 times the service life of standard black oxide bits. The variable helix geometry—featuring an aggressive 35-degree angle that transitions to 15 degrees—enables rapid chip removal and minimizes heat buildup, keeping the bit sharper longer. The 135-degree split point tip delivers a precision start and prevents walking, ensuring fast and accurate holes in tough applications.

Features and Benefits

• Cobalt Construction: Delivers exceptional durability and heat resistance for consistent results during extended use in hard metals.
• 135-Degree Split Point Tip: Provides precision starting and prevents walking for fast, accurate holes without slipping.
• RED HELIX Variable Design: The optimized helix angle promotes aggressive chip removal and limits heat buildup, extending tool life up to 10 times longer than black oxide bits.
• 3-Flat Shank: Eliminates chuck slippage, ensuring secure grip and reliable power transfer from your drill.
• Jobber Length Profile: The 5-1/8-inch overall length suits a wide range of drilling tasks in metal work and general applications.

Specifications

• Brand: Milwaukee
• Model: 48-89-2321
• Bit Type: Jobber, twist flute, 3-flute
• Diameter: 3/8 inch
• Overall Length: 5-1/8 inches
• Shank Diameter: 3/8 inch
• Material: Cobalt with RED HELIX design
• Tip Angle: 135-degree split point