CRL HBT 3/4in Belgian-Thread Electroformed Diamond Drill Bit

• Fast cutting for high-production glass drilling
• Extended work life with multi-layer diamond bond
• Two mounting styles: Straight shank (DCD) or Belgian type (HBT) threads

These CRL Electro-Formed Diamond Drills are thin-walled electro-formed diamond drill bits engineered for high-speed, high-production drilling of flat plate glass. Each bit has a 1/2" (12.7 mm) deep multi-layer diamond and bonding matrix for consistent cutting performance. The CRL DCD Series offers an extra-long 1-3/8" x 3/8" (35 x 9.5 mm) diameter shank for a positive grip; the CRL HBT Series (SKU HBT34) uses Belgian style mounting threads (1/2" gas thread), a common choice for U.S. and European glass drilling machines.


Because these drills have an extremely thin wall, they are FRAGILE and must be used only in a precision, production-style drilling press. Never apply excessive pressure; use on flat, horizontal surfaces only. Sharpening or "dressing" the drill with a dressing stone before each use significantly improves cutting capability—keep a dressing stone on hand when working with electro-formed diamond drills.

IMPORTANT NOTE: CRL DCD and HBT Series diamond drills are intended exclusively for drilling flat (plate) glass in a true running production press. These thin-walled bits are EXTREMELY FRAGILE.

NEVER perform freehand drilling. If using a handheld drill, stabilize with a dedicated glass drilling base such as the GDB1 or GDB2. Improper use can damage the bit and void the warranty.

Always wear appropriate personal protective equipment—gloves and eye protection—when drilling glass. Use a Ground Fault Circuit Interrupter (GFCI) whenever electrical tools are used with water or coolant. Failure to follow these precautions can result in operator injury.