Hertel 30015900 Circuit Board Drill Bit No. 21 Wire Size

Product Description

The HERTEL 30015900 is a solid carbide circuit board drill bit designed for high-precision drilling in printed circuit board (PCB) fabrication and related precision machining work. Sized to wire gauge No. 21, this bit measures 0.1590 inches (4.04 mm) in diameter with a matching shank diameter of 0.1590 inches. The 118-degree drill point angle and fast spiral flute geometry allow efficient chip evacuation and clean entry in tight-tolerance applications. At 1.5 inches overall length with a 0.75-inch flute length, the compact profile suits the short-depth drilling typical in PCB and small-part work. Right-hand cutting direction and a tapered web configuration contribute to accurate, repeatable hole placement.

This drill bit is suited for use on cast iron, non-ferrous metals, and steel. It is most commonly applied in precision manufacturing environments, electronics fabrication shops, and toolroom operations where hole location accuracy and surface finish are critical. The bright polished coating reduces friction and helps maintain dimensional accuracy at the cutting edge. A 35-degree helix angle supports fast chip removal when drilling shallow-depth holes at high spindle speeds.

Key Features

• Solid carbide construction for rigidity and wear resistance in precision drilling
• No. 21 wire size, 0.1590 inches (4.04 mm) diameter, with a matching 4.04 mm shank
• 118-degree drill point angle with tapered web for accurate hole entry
• Fast spiral flute with 35-degree helix angle for efficient chip evacuation
• Bright polished finish reduces friction and extends cutting edge life
• Rated for cast iron, non-ferrous metals, and steel applications

Compatibility

Designed as an OEM-style precision drill bit for circuit board and small-part drilling operations requiring a No. 21 wire gauge diameter hole in a standard straight-shank configuration.

Installation Notes

Installation of this drill bit is performed by machinists and toolroom technicians using a compatible precision drill press, CNC drilling machine, or high-speed spindle with a collet or chuck rated for the 4.04 mm shank diameter. Ensure the spindle is fully stopped and the machine is de-energized before loading or unloading the bit. Solid carbide tooling is brittle — avoid side loading, interrupted cuts without proper feed rate adjustment, and contact with hard inclusions that exceed the bit's rated material application. Follow the machine manufacturer's recommended speeds and feeds for solid carbide tooling in the applicable workpiece material.