Hertel 30003900 Circuit Board Drill Bit No. 61 0.99mm

Product Description

The HERTEL 30003900 is a solid carbide circuit board drill bit sized at No. 61 wire gauge, equivalent to 0.0390 inches (0.99mm) in diameter. It features a 118-degree drill point angle and a fast spiral flute design with a 35-degree helix angle, making it well suited for clean, accurate through-holes in printed circuit boards and other precision applications. The tapered web configuration adds rigidity while the bright polished finish reduces friction and chip buildup. Right-hand cutting direction is standard. This bit is intended for use in CNC drilling machines and precision drill presses operated by machinists, electronics technicians, and skilled trade professionals working in light manufacturing or electronics assembly environments.

The 30003900 is rated for use in cast iron, non-ferrous metals, and steel in addition to circuit board substrates. With a 0.625 inch flute length and a 1.5 inch overall length, the bit fits standard small-shank drill chucks and CNC board-drilling spindles. Its heavy-duty grade carbide construction makes it appropriate for production drilling cycles where consistent hole geometry and bit longevity are priorities. Typical applications include PCB fabrication, instrument panel drilling, and precision metalwork requiring fine wire-gauge hole sizes.

Key Features

• Solid carbide construction for hardness and wear resistance in production environments
• No. 61 wire gauge size — 0.0390 inches (0.99mm) diameter for precision small-hole drilling
• 118-degree drill point angle with tapered web for accurate entry and reduced walking
• Fast spiral flute with 35-degree helix angle promotes efficient chip evacuation
• Bright polished coating reduces friction and heat buildup during drilling
• Right-hand cutting, compatible with standard CNC and bench-top spindle rotation

Compatibility

Designed as an OEM-style replacement or direct-use bit for CNC circuit board drilling machines and precision drill presses that accept small-shank carbide bits with a 0.99mm shank diameter. Suitable for drilling cast iron, non-ferrous metals, and steel per manufacturer material application data.

Installation Notes

Installation and use of this bit should be performed by qualified machinists or precision drilling technicians familiar with small-diameter carbide tooling. Ensure the spindle and chuck are fully powered down and at rest before inserting or removing the bit. Carbide tooling is brittle — avoid lateral loading, side pressure, or impact during setup. Verify spindle runout is within acceptable tolerance before beginning production drilling to prevent premature breakage of this fine-diameter bit.