Hertel 79892220 Solid Carbide Jobber Drill Bit No. 21

Product Description

The HERTEL 79892220 is a solid carbide jobber length drill bit sized to No. 21 wire gauge (0.1590 inches diameter) with a 118-degree standard point angle. Built to C2 carbide material grade, it delivers the rigidity and heat resistance needed for drilling hard materials at high cycle counts. The bright finish leaves the carbide uncoated for direct heat dissipation. At 2.5 inches overall length with a 1.375-inch spiral flute, it fits standard drill chucks and CNC toolholders in light to medium production environments. Installed by machinists, tool-and-die techs, and maintenance tradespeople running manual or CNC drilling operations.

This drill bit suits precision drilling in metal fabrication, maintenance-repair-operations (MRO), and light manufacturing. The No. 21 wire-gauge diameter is commonly used for tap-drill and clearance-hole applications on small fasteners. The right-hand cut and regular spiral flute geometry handle a broad range of ferrous and non-ferrous materials. Web-thinned geometry reduces thrust force at drill entry, which is especially useful when drilling by hand or on lower-horsepower spindles.

Key Features

• Solid carbide construction, C2 material grade for extended tool life in hard and abrasive materials
• No. 21 wire size, 0.1590-inch diameter with a tight tolerance of -0.0005 to 0.0000 inches
• 118-degree standard point angle with web-thinned, tapered web configuration for reduced entry thrust
• Bright (uncoated) finish maintains sharp cutting edge geometry out of the box
• Right-hand cut, 2-flute regular spiral for efficient chip evacuation
• Straight-cylindrical shank at 0.1590 inches fits standard drill chucks and collets

Compatibility

Designed as a jobber-length replacement drill bit for No. 21 wire gauge applications in standard drill chucks, CNC machining centers, and benchtop drill presses accepting a 0.1590-inch straight shank.

Installation Notes

Installation and use should be performed by qualified machinists or maintenance tradespeople familiar with cutting tool setup. Secure the straight-cylindrical shank fully in the chuck or collet before operation and verify runout is within acceptable limits. Always power down and de-energize the spindle before changing tooling. Do not exceed the recommended speed-and-feed range for the workpiece material and machine horsepower.