Bosch GT400 5/16 Inch Glass Tile Drill Bit 3-pack

Product Description

The ROBERT BOSCH TOOL GROUP GT400 is a 5/16-inch carbide-tipped drill bit engineered specifically for drilling through glass and tile. The precision tip design eliminates bit wander and bit walking at the start of a hole, a common problem on hard, slick surfaces. The reinforced carbide head resists cracking under the lateral stress of tile drilling and extends service life compared to standard masonry bits. The three-flat shank prevents rotation inside the chuck, keeping the bit seated and reducing operator fatigue. This bit is sold in a pack of 3 and is suited for tile setters, plumbers, electricians, and general contractors who drill through ceramic, porcelain, or glass as part of rough-in or finish work.

The GT400 is appropriate for residential and light commercial applications where penetrations through tile walls, glass panels, or similar hard surfaces are required. Typical scenarios include plumbing fixture installations, electrical outlet cutouts in tile backsplashes, and HVAC grille penetrations through tiled surfaces. The innovative flute geometry accelerates material removal so the bit clears debris efficiently and reduces heat buildup at the cutting face, which is critical when working on brittle materials like porcelain or tempered glass.

Key Features

• Precision tip eliminates bit wander and bit walking on hard, slick surfaces
• High-quality carbide tip with reinforced head resists cracking and extends bit life
• Three-flat shank prevents slippage inside the chuck during drilling
• Innovative flute geometry allows faster drilling and efficient debris clearance
• Sold as a 3-piece pack for job-site redundancy

Compatibility

Designed for use in standard keyed or keyless drill chucks that accept a three-flat shank; suitable for drilling glass, ceramic tile, and porcelain tile surfaces.

Installation Notes

A licensed tradesperson or experienced installer should use a variable-speed drill at low RPM with steady, moderate pressure when drilling glass or tile to avoid cracking the substrate. Power down the drill before changing bits and confirm the three-flat shank is fully seated and the chuck is tightened before beginning. Water or a cooling lubricant applied at the drill point helps manage heat on hard ceramic and glass surfaces. Follow all applicable site safety and personal protective equipment requirements when working with brittle materials.