Busch 4203 4 Groove Carbide Twist Drills on 3/32" Shanks .70mm-1.60mm - Kit of 10

These Busch 4203 carbide twist drills feature a 4-groove design optimized for cutting softer organic materials such as coral and pearls. Mounted on 3/32" shanks, this kit provides ten drills ranging from 0.70mm to 1.60mm, offering a complete size progression for fine drilling work. The 4-groove geometry delivers outstanding service life when used correctly and within recommended operating parameters.

For best results and longest tool life, use these drills in a drill press. As with any drill, breakage can occur from excess leverage or canting. When drilling freehand, operate at 5,000–9,000 RPM; a starting guide hole is strongly recommended for freehand use. In a drill press, the recommended speed range is 8,000–14,000 RPM.

Not for use with glass, ceramics, or gemstones.

Features

• 4-groove carbide construction optimized for softer materials
• Recommended for drilling coral and pearls
• Outstanding service life with proper use
• Mounted on standard 3/32" shanks
• Complete size range from 0.70mm to 1.60mm in 0.10mm increments
• Suitable for use in a drill press or freehand handpiece

Specifications

What's Included

• B128.707 – 0.70mm
• B128.708 – 0.80mm
• B128.709 – 0.90mm
• B128.710 – 1.00mm
• B128.711 – 1.10mm
• B128.712 – 1.20mm
• B128.713 – 1.30mm
• B128.714 – 1.40mm
• B128.715 – 1.50mm
• B128.716 – 1.60mm

Notes

• Using a starting guide hole is strongly recommended when drilling freehand.
• Breakage may occur if excess lateral force or canting is applied during use.
• Drill press use is recommended for maximum tool longevity.

California Prop 65 Warning:
Cancer and Reproductive Harm. www.P65warnings.ca.gov.