Bosch HDG138QA 1-3/8 Inch Diamond Grit Hole Saw Kit AutoStart Pilot Bit Mandrel for Granite Stone Tile Countertops

THE COMPLETE SOLUTION FOR DRILLING HARD COUNTERTOPS AND STONE

Take the guesswork out of drilling into the hardest surfaces with the Bosch HDG138QA 1-3/8 Inch Diamond Grit Hole Saw Kit. This all-in-one set is expertly curated to provide everything you need for cutting clean, precise holes in granite, porcelain, marble, and natural stone. The included hole saw features vacuum-brazed diamond grit technology, which cuts faster and lasts significantly longer than standard masonry bits. With a generous cutting depth of 1.5 inches, this tool is perfectly sized to bore through thick countertops, making it the ideal choice for installing standard kitchen faucets and garbage disposal air switches.

What sets this kit apart is the inclusion of the innovative AutoStart™ Pilot Bit and the Quick Change™ Mandrel. Drifting or "walking" is a common problem when starting holes on smooth stone, but the spring-loaded AutoStart pilot bit solves this by retracting as you drill, ensuring a walk-free start without the need for a pre-drilled pilot hole. The Quick Change mandrel allows you to swap hole saws in seconds and simplifies plug removal, keeping your workflow efficient. Whether you are a professional installer or a DIY enthusiast upgrading a kitchen, this kit delivers professional results on the toughest materials.

Key Features

• Complete Kit: Includes diamond hole saw, mandrel, and retractable pilot bit for immediate use out of the box.
• Vacuum-Brazed Diamonds: Fused diamond grit provides superior durability and faster cutting in hard masonry.
• AutoStart™ Technology: Spring-loaded retractable pilot bit shaft prevents bit walking for accurate hole placement.
• Segmented Teeth: Designed to reduce heat buildup and efficiently remove debris during wet cutting.
• Quick Change System: Allows for rapid accessory changes and easy material plug removal.
• Ideal Application: Perfect size (1-3/8 in.) for faucet installations and disposal air switches in granite and stone.
• Deep Cut Capacity: 1.5-inch depth easily penetrates standard countertop slabs and pavers.

What's Included

(1) 1-3/8 Inch Diamond Grit Hole Saw, (1) Quick Change Mandrel, (1) AutoStart™ Retractable Pilot Bit

Specifications

Pro-Tip: Heat is the primary cause of diamond bit failure. When drilling through thick granite countertops, create a "dam" around the hole location using plumber's putty and fill it with water. This keeps the diamonds submerged and cool throughout the entire cut, preventing overheating and extending the life of your tool.