Drill Bit Makita SDS‑MAX 20 mm MA-D-33978 for rotary hammers

Makita SDS‑MAX 20 mm drill bit MA-D-33978 is a rotary-hammer accessory designed for drilling clean, accurate 20 mm holes in concrete, masonry and similar mineral materials. It is built for use with SDS‑MAX rotary hammers and provides the geometry and shank compatibility required for impact drilling with hammer action. The bit is intended for construction and renovation tasks where repetitive drilling into hard substrates is required.

Advantages

The bit features a robust carbide tip and flute design that facilitate fast dust removal and maintain drilling efficiency under heavy load. Its SDS‑MAX shank ensures secure engagement in compatible rotary hammers, reducing slippage during hammering. Precision ground cutting edges offer consistent hole diameter and straight drilling, while the durable body resists wear during repeated professional use.

Suitable for

• Drilling 20 mm holes in concrete and reinforced concrete
• Anchor and dowel installation in masonry
• Chasing and service openings where through-holes are required
• Construction and renovation site tasks with rotary-hammer tools

Key specifications

• Shank type: SDS‑MAX compatible
• Cutting diameter: 20 mm
• Intended materials: concrete, masonry and similar mineral substrates
• Tip material: carbide cutting tip for increased wear resistance
• Flute design: optimized for dust evacuation during hammer drilling

How to use

Select a compatible SDS‑MAX rotary hammer and secure the bit in the chuck according to the tool manufacturer's instructions. Mark the drilling point, start at low speed to position the bit, then apply steady pressure while engaging the hammer function for impact drilling. Periodically withdraw the bit to clear dust and check progress; for deep holes, pull out frequently to improve debris removal. Use appropriate personal protective equipment including eye protection, hearing protection and a dust mask when drilling.

Usage recommendations

For best results, match drill diameter and bit length to the anchor or fixture being installed and avoid excessive lateral forces. Use water sparingly only if recommended for the specific task and tool; in most masonry hammer-drilling applications, keep the bit clean and replace it when wear reduces drilling performance.