SDS: Decoded

SDS, Plus, Max, Spline, Hex…what’s the deal? Why are there so many different options? Which one do I need? While selling tools, I have heard these questions probably more often than any other, so I’ll try to break it down for you here.

In the beginning, there was SDS. Bosch introduced the Special Direct System (SDS) Drills to the market in 1975, and since then all the other major manufacturers have gotten on board with their own SDS compatible versions. SDS tools differ from regular hammer drills because the drill bit hammers within the chuck as opposed to the entire chuck moving. This provides for more efficient operation and more power than conventional hammer drills.

Next came the evolution of SDS to SDS Plus. SDS Plus bits work in both plus and standard SDS drills. SDS and SDS plus bits are 10mm shanks inserted 40mm into the chuck.

After Plus came SDS Max. SDS Max drills are even more heavy duty that the SDS Plus. They use an 18mm Shank and are inserted 90mm into the drill chuck. The bits are not compatible with SDS plus, but Plus bits can be used in a Max drill with an adapter.

Also there is Spline. Spline tools technically don’t use the SDS system but have very similar specs and uses to the SDS max tools. The bits are not cross compatible but adapters are available to interchange spline and max bits.

So, after these explanations, which one do you need? The tool, either in their name or product description, will say, for example; “Bosch 11224VSR 7/8-in SDS-Plus Bulldog Rotary Hammer”. What this means broken down is: Bosch = Brand, 11224= model number, VSR=Variable Speed Reversing, 7/8-in =max through hole diameter in concrete, SDS-plus = type of bits accepted, and rotary hammer= the tool will drill, hammer drill, or hammer only. But what does this mean for you?

The max through hole diameter, the type of bit accepted, and the type of tool are the most important things you need to know. If you often need to drill 2″ holes through floors or walls to push conduit through, you need a drill rated at 2″, but if you only drill 5/8″ holes for anchors, you can buy a drill with a lower max through hole diameter, because you don’t need as much power or torque. Similarly, the SDS-plus is a lighter duty tool than SDS-max and provides less torque and less power for a lighter duty job, where SDS-Max is heavy duty for serious drilling or demolition. Finally there is the type of tool; Most rotary hammers will drill, hammer drill or chisel, but a demo hammer will only chisel but not drill.

Last but not least, there are Hex hammers. These tools like spline drives are not technically SDS but provide a similar function. Hex bits are used for heavy demolition in breaker hammers and demo hammers and are not for drilling. They are available in 3/4″ and 1 1/8″ shanks. The 1 1/8″ hex bit is the size most commonly used in jack hammers in the 35-80 lb class.

I hope this helps clarify the differences in the tools and bits available, but if you still have any questions, feel free to leave them in the comments below.

Click here to see the full line of Bosch SDS Rotary Hammers.

Click here to see the full line of Bosch SDS Bits and Chisels.


Bosch GTS1031

My friend Ethan at One Project Closer wrote this awesome review of the new Bosch portable jobsite table saw. Thanks Ethan!

Table saws are a must have tool whether you’re installing hardwood flooring or sheathing new construction. No contractor’s inventory is complete without one. Cabinet table saws are perfect for the shop but it’s important to be able to pack-up and go. That’s where the GTS1031 fits in.

The new Bosch GTS1031 is a 10″, compact table saw designed for the job site. A well placed handle makes it easy to carry one-handed, and all the accessories are safely stored within the all-steel frame. The 18″ rip capacity is shorter than we would prefer but surpasses competitors within the same class. Even so, it’s an excellent option to consider for your next purchase.

Traveling between job sites can wreak havoc on the toughest of tools. The rip fence is often the most exposed component and the first casualty. Bosch understands this and found storage space within the steel frame for all the accessories including the rip fence. There is no wasted space here. This approach also enables you to store the GTS1031 on its side, taking up a smaller portion of your truck.

If you’ve ever carried a table saw, you know it’s usually a two handed operation. One-handed carry is an important feature because it saves time at the job site. Making fewer trips means getting the job done faster. The padded handle is securely attached to the frame and well balanced for easy transportation.

Bosch equipped this saw with a 4hp, 5,000rpm motor that powers through materials with ease. The bevel adjustments (-2° to 52°), and dado capabilities (1/2″) mean this saw can tackle a variety of projects. The Squarelock Rip Fence moves easily along the rails and provides an precise cut each time. The Bosch GTS 1031 has a respectable 18″ rip capacity but falls short of the ideal 24″. At two feet, you’re able to cut sheet goods in half without extra cuts. This is a fair trade-off considering the small form factor, and even at 18″, the GTS1031 is more capable than similar models.

Setup is quickly achieved by raising the blade and riving knife, and locking the safety guard and anti kickback pawls in place. This saw is streamlined for performance with no unnecessary frills.

At 22.5″ square and 13″ high, the GTS1031 is extremely compact and has one of the smallest footprints available. It weighs 52 lbs, making it slightly heavier than comparable models.

There are several compatible accessories including dust collection, a zero clearance insert and the GTA500 stand.

Click here to view the full post by One Project Closer with tons of pictures.

Click here for more specs and to order the GTS1031.