At first glance, drill drivers and hammer drill drivers (sometimes just called hammer drills) look very similar. However, hammer drill drivers have an extra hammering function built in. 

With Hilti drill drivers, you can spot the models with a hammering function by the letter 'H' in the name - for example the SF 2H-A12, SF 4H-22 or the SF 6H-22. 

If you are drilling small holes into wood or steel, you may not need this hammering function. But for drilling into tougher materials like brick, masonry and aerated concrete, this hammering function can really speed up your work. This is especially important if you are drilling lots of holes.

Depending on the work you are doing with your hammer drill driver, you can switch between drilling and hammer drilling mode.

A drill driver is used for drilling holes in a base material like masonry, wood or metal, or for driving larger fasteners into those base materials. On the other hand, a screwdriver is only designed to drive screws into a base material.

Screwdrivers have a different ergonomic design to drill drivers. They are longer and have an in-line grip for improved handling and user comfort. In terms of how they operate, screwdrivers do not always rotate when you pull the trigger. The user must apply pressure to the bit to engage the clutch and drive the screws. This allows depth adjustment and the use of screw magazines.

Hilti offers speciality high-speed and high-torque screwdrivers for applications such as hanging drywall or wood boards (SD 5000-22) or driving into steel and aliminium as well as for siding and decking jobs (ST 2000-22). These screwdrivers have a built-in mechanical torque clutch that disconnects the power supply when the screw process is completed to prevent unnecessary torsion and over-compression.

Hard joint torque refers to the maximum amount of torque you could possibly get when working with harder materials like stainless steel. Soft joint torque is the maximum amount of torque you are drilling or driving into softer materials like some types of wood.    

Torque is rotational (twisting) force, or the force used by a drill driver or a screwdriver to turn an object. It is usually measured in pounds per square inch or newtons per meter (Nm).

Torque is a key factor when you are choosing which drill driver or screwdriver to buy. You need to make sure you have enough torque for drilling or driving fasterners into the base material you are working with. For example, if you are drilling or driving into harder materials like concrete or metal, you're going to need more torque. But if you have use much torque - for example on a softer material like wood - you can damage the fastener or the base material. 

Ideally, your tool should have different torque settings so you can control how much twisting force you need. You can then do more jobs with the same tool by changing the amount of torque. 

Torque is an esssential part of tool performance but it is definitely not the only factor. Higher torque does not equal faster working speed. And having a tool with higher torque doesn't automatically mean you are going to be able to work faster. 

To calculate the power of a tool, you need to look at both torque (rotational force) and speed. These two factors work together to tell you how powerful it is.    

Active Torque Control (ATC) is a safety feature found in many Hilti drills and grinders. It helps protect the tool operator when a drill bit or blade binds in solid material. ATC rapidly cuts power to the motor before the tool housing can spin out of control.