SDS-Max RX4 4-Cutter Concrete Drill Bit

A four-cutter hammer drill bit with an SDS-Max shank for demolition and breaker hammers — fast, straight drilling in reinforced concrete and hard masonry.

SDS-Max shank4-cutter carbide headFor breaker / demolition hammersReinforced concrete & hard masonryFast, straight boring

The Adit drill-bit family

Choose the right drill bit for your machine chuck and drilling job.

Technical specification

Instructional & field videos

SDS-Max 4-cutter drill bits: the complete guide

Everything you need to know about the SDS-Max RX4 four-cutter concrete drill bit — from the head geometry, through the correct machine, all the way to getting clean, straight holes for chemical and mechanical anchoring. This guide was written by the experts at Adit Ltd., the largest anchoring and fastening company in Israel.

What is an SDS-Max 4-cutter drill bit and how does it work?

An SDS-Max drill bit uses the larger SDS-Max shank system, which locks into breaker and heavy rotary hammers and lets the machine deliver a powerful hammering action along the axis of the bit. Where a standard two-cutter tip has a single carbide blade, the 4-cutter (RX4) head carries a full carbide cross with four cutting edges.

The four edges share the impact energy over more contact points, so the bit stays centred, drills straighter and passes through rebar and hard aggregate far more smoothly than a two-cutter tip. The result is a rounder hole, less wandering at the start and a longer working life of the carbide.

The cutting principle

As the hammer rotates and strikes, the four carbide edges chip the concrete while the deep spiral flute lifts the dust up and out of the hole. Efficient dust removal keeps the tip cool and cutting, which is what makes the difference between a fast, clean bore and a bit that overheats and slows down.

How to drill correctly with an SDS-Max RX4 bit

1. Match the machine — use an SDS-Max breaker or heavy rotary hammer set to rotary-hammer mode. Never force an SDS-Max bit into a smaller SDS-Plus chuck.
2. Insert and lock the shank — push the bit into the chuck until it clicks and check that it is retained before starting.
3. Start straight — begin at low speed to let the four cutters bite and centre the hole, then increase to full hammering.
4. Let the tool do the work — apply steady, moderate pressure. Excess force does not drill faster and only wears the carbide.
5. Clear the hole — withdraw the bit a few times while drilling to help the flute evacuate dust, then brush and blow the finished hole clean before anchoring.

Advantages of the four-cutter head

• Straighter holes: four symmetrical edges keep the bit centred, so holes stay round and on-axis — important for anchor fit and edge distances.
• Better through rebar: the carbide cross cuts through reinforcement bars more smoothly than a single blade, reducing snatching and bit deflection.
• Longer life: the impact load is spread over more cutting edges, so each edge wears more slowly.
• Faster dust removal: the deep spiral flute keeps the tip clean and cool for a consistent drilling rate.
• Less operator fatigue: smoother, more stable drilling means less vibration transmitted to the hands.

Where the SDS-Max RX4 is used

The SDS-Max RX4 is the tool of choice wherever large-diameter, deep holes are needed in structural concrete, typically for chemical and mechanical anchoring on:

• Bridges, tunnels and heavy civil infrastructure
• Multi-storey car parks and industrial floors
• High-rise cores and shear walls
• Foundations and retaining structures
• Steel-to-concrete connections and machine bases

Why choose Adit Ltd. for your drilling and anchoring?

Adit Ltd. — the largest company in the anchoring field in Israel today — supplies not only the drill bits but the complete anchoring system that goes into the hole you drill:

• Matched consumables: drill bits, cleaning brushes and chemical or mechanical anchors that work together as one system.
• In-depth engineering support: engineers who help with hole diameter, embedment depth and load calculation.
• Field training: agents with many years of experience come to site and demonstrate correct drilling and cleaning.
• Immediate stock: fast supply to any point in the country from the largest warehouse in Israel.

Frequently asked questions