Drill bit Proxxon 28842 Diamond drill bit Ø 3.8 cm, 1 pc

Proxxon 28842 Diamond drill bit Ø 3.8 cm is a single, diamond-coated hole saw designed for precise cutting and drilling in very hard and brittle materials. Supplied as one piece with a mandrel and a 3/32" (2.35 mm) shank, the wheel has an outer diameter of 38 mm and a cutting rim thickness of approximately 0.6 mm. The tool is intended for use with compatible rotary drills and drill presses when diamond-tipped performance is required for clean, accurate holes in masonry, ceramics and similar substrates.

Advantages

The diamond-coated rim provides high abrasion resistance and consistent cutting performance on hard surfaces. A thin cutting edge (about 0.6 mm) minimises material loss and reduces the need for secondary finishing. The included mandrel with a 3/32" (2.35 mm) shank ensures compatibility with a wide range of handheld drills and drill presses. Overall design delivers precise, round holes with reduced chipping on brittle materials.

Suitable for

• Drilling holes in glass and tempered glass
• Ceramic and porcelain tile hole cutting
• Creating openings in fiberglass and plastics
• Working with non-ferrous metals and thin steel where diamond cutting is needed
• Masonry and stone applications requiring a diamond-tipped hole saw

Key specifications

• Cutting diameter: 38 mm
• Cutting rim thickness: approx. 0.6 mm
• Shank size: 3/32" (2.35 mm)
• Diamond-coated cutting edge for abrasion resistance
• Supply: single piece with mandrel

How to use

Mount the mandrel securely in the drill chuck and ensure the shank is fully seated. Mark the drilling position and start drilling at low speed to establish a guiding groove; apply light, steady pressure and keep the tool perpendicular to the workpiece. For brittle or heat-sensitive materials, use intermittent drilling and coolant (water) to avoid overheating and to extend the diamond rim life. After cutting, stop the drill and carefully remove the tool from the hole to prevent chipping.

Usage recommendations

Use water as coolant during drilling to reduce heat and wash away debris. Select a low to moderate rotational speed and avoid excessive axial force. For best results on tile, start with a pilot groove or use masking tape to reduce slippage. Regularly check the mandrel tightness and replace the bit when cutting performance visibly declines.