If you’re shopping for a rotary hammer drill or percussion bits, you’ve probably heard “SDS Plus” and “SDS Max” thrown around. The names sound similar, but they’re completely different systems—and mixing them up is one of the quickest ways to waste money or damage your tool.
This guide breaks down exactly what makes each one different, when you need each type, and whether you can adapt between them.
SDS Plus vs SDS Max — Quick Comparison
| Feature | SDS Plus | SDS Max |
|---|---|---|
| Shank Diameter | 10mm | 18mm |
| Slot Pattern | 2 open + 2 closed slots | 3 open + 2 closed slots |
| Bit Size Range | 4–30mm diameter | 12–52mm+ diameter |
| Typical Drill Size | 500–1,500W rotary hammers | 2,000W+ heavy-duty demolition rigs |
| Common Uses | General masonry, concrete, brick up to 25mm holes | Large holes, reinforced concrete, demolition work |
| Chuck Compatibility | Fits all SDS Plus rotary hammers (brand-independent) | Fits all SDS Max rotary hammers only |
| Can Cross-Use? | NO — different shank diameters | |
What Does SDS Stand For?
SDS is short for the German phrase Steck-Dreh-Sitz (literally “insert-twist-seat”), though Bosch, the inventor, calls it “Spannen durch System” (clamping via system). It’s a quick-change chuck mechanism that grips the shank via a series of open and closed slots rather than a traditional 3-jaw chuck. The bit twists into place and locks automatically—no chuck key needed.
The real genius of SDS is that you can change bits one-handed in seconds, even while the drill is running (though that’s not recommended). For professional masons and demolition crews working all day, this saves enormous amounts of time and fatigue.
SDS Plus Explained — The Standard System
SDS Plus is the most common percussion drilling system worldwide. It uses a 10mm shank with 2 open and 2 closed slots running along the length of the bit. Every major manufacturer—Bosch, Makita, DeWalt, Milwaukee, Hilti, and dozens of others—makes SDS Plus rotary hammers.
Typical SDS Plus Specs
- Shank diameter: 10mm
- Bit size range: 4mm to 30mm diameter (with speciality bits up to ~40mm)
- Fit: Fits all SDS Plus rotary hammers, regardless of brand
- Energy: Designed for 1–3kg percussion force, typical of mid-range hammers (500–1,500W)
- Best for: Brick, block, concrete up to ~250mm depth, general site and trade use
For most tradespeople and serious DIYers, SDS Plus is your go-to. A typical job might be drilling anchor holes through brick for cavity wall fixings, drilling out concrete for pipe runs, or setting dowels into masonry.
SDS Plus bits are wildly available, competitively priced, and work reliably across all brands. Buy SDS Plus bit sets on Amazon.
SDS Max Explained — The Heavy-Duty System
SDS Max (also called “SDS Plus Max” in some regions) is the big brother. It uses an 18mm shank with 3 open and 2 closed slots. This larger shank can handle the massive percussion forces of heavy-duty demolition rigs—often 4kg+ impact energy.
Typical SDS Max Specs
- Shank diameter: 18mm
- Bit size range: 12mm to 52mm+ diameter (sometimes larger speciality bits)
- Fit: Fits all SDS Max rotary hammers only
- Energy: Designed for 4–6kg+ percussion force, typical of 2,000W+ demolition hammers
- Best for: Large-diameter holes in heavy reinforced concrete, structural demolition, deep piling
You’ll find SDS Max on professional demolition sites, in heavy construction, and with contractors who drill holes 50mm+ in diameter daily. A typical SDS Max job might be drilling through a reinforced concrete beam for MEP (mechanical, electrical, plumbing) runs, or creating pilot holes for rock anchors.
Buy SDS Max bit sets on Amazon.
Can You Use SDS Plus Bits in an SDS Max Drill?
No. Do not try this.
The shank diameters are completely different (10mm vs 18mm), so a Plus bit simply won’t fit in a Max chuck. There’s no mechanical way to make it work without an adapter, and even with an adapter, you’d be fighting the system.
What About Adapters?
Technically, adapters exist that let you fit SDS Plus bits into SDS Max chucks, and vice versa. Don’t use them. Here’s why:
- Safety: The adapter adds length and changes the bit balance. Under high percussion forces, this can cause bit breakage or tool damage.
- Performance: You lose the efficient transfer of hammer energy from the chuck to the bit. The drill works harder and slower.
- Wear: Mismatched adapters wear the chuck faster than genuine bits.
Use the bit size that matches your drill. It’s not worth the risk.
SDS Plus and SDS Max Are Universal Within Their System
The beautiful part of SDS design is that bits are completely brand-independent. An SDS Plus bit from Bosch works identically in a Makita SDS Plus drill, a DeWalt, a Milwaukee, or a Hilti. Same for SDS Max.
This means you can buy the cheapest SDS Plus bits on the market and they’ll work just as well in a premium drill. Compatibility is guaranteed by the shank geometry.
If you’re setting up a toolkit, this is massively convenient—you’re not locked into one brand’s bit ecosystem like you might be with some proprietary systems.
SDS Quick-Change — Bosch’s Tool-Free System
In recent years, Bosch introduced SDS Quick on some models—a faster, tool-free chuck that doesn’t even require a twist-in motion. Push the bit and it locks; pull a collar to release.
SDS Quick bits have a slightly different geometry but are sold alongside standard SDS bits. If you’re buying a new drill, check your manual to confirm which system yours uses. Most trade drills still use traditional SDS Plus or SDS Max.
When to Use SDS Plus vs SDS Max
Use SDS Plus If You’re:
- A DIYer hanging a shelf on a brick wall
- A tradesperson drilling cable runs through blockwork
- Setting cavity fixings or masonry anchors
- Doing general-site concrete work with holes under 25mm
- Working in confined spaces where a lighter drill is easier to control
Use SDS Max If You’re:
- A demolition contractor breaking out concrete
- Drilling multiple large-diameter holes (40mm+) in reinforced concrete
- On a major construction site doing structural work
- Drilling deep into heavy concrete daily as part of your job
- Setting large resin anchors or piling holes
In short: SDS Plus is for most people and most jobs. SDS Max is for professionals doing serious, heavy-duty work.
How SDS Fits Into Your Drill Bit Toolkit
If you own a rotary hammer, make sure you know which system it is. Check the manual or look at the chuck itself—the shank diameter and slot pattern are visible.
Once you know, stock a variety of drill bits for different jobs. SDS Plus kits typically include 4–8 bit sizes (4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 30mm). For occasional use, a basic set is enough. For trade work, buy in bulk and rotate worn bits out regularly.
For wood drilling, you’ll need a separate chuck adapter or a standard drill with round-shank bits—SDS is purely for masonry and concrete.
Watch: Video Guide
Frequently Asked Questions
Is SDS the same as SDS Plus?
Basically yes. The original SDS system and SDS Plus use the same 10mm shank geometry. Some older literature calls it just “SDS,” but modern bits are labelled “SDS Plus” to distinguish them from the larger SDS Max. For your purposes, they’re identical.
What’s the difference between SDS and hammer drill?
A hammer drill is any drill that combines rotation with a rapid percussion (hitting) motion. SDS is one type of chuck used on hammer drills. You can have SDS Plus hammer drills, SDS Max hammer drills, and rotary hammers (which are heavier-duty percussion tools). See our guide on rotary hammer vs hammer drill bits for more detail.
Can I use SDS bits in a standard drill?
No. SDS bits have a special shank that only fits SDS chucks. You’d need an SDS-to-round-chuck adapter, which defeats the purpose and adds cost. For a standard drill, use round-shank or hex-shank bits.
Which manufacturers make SDS Plus drills?
Nearly all major brands: Bosch, Makita, DeWalt, Milwaukee, Hilti, Festool, AEG, and many others. SDS Plus is the industry standard for mid-range percussion drilling.
How do I know if my drill is SDS Plus or SDS Max?
Look at the chuck. SDS Plus has a 10mm shank slot; SDS Max has an 18mm shank. Or check your manual—it will always specify. You can also measure: SDS Plus = 10mm, SDS Max = 18mm.
Are SDS Max bits more durable?
Not necessarily. Both types are made from similar materials (carbide, tungsten, or steel depending on grade). SDS Max bits are larger and heavier, which makes them suitable for larger holes and higher percussion forces. For small holes in general masonry, SDS Plus bits are perfectly durable.
