subject: Types Of Cordless Drill [print this page] The drilling or screw driving capacity of the various types of cordless drill is largely determined by the voltage and battery capacity (Ah). Broadly speaking, the higher the voltage, the larger the hole it will drill or screw it will drive. Also, a higher battery capacity will usually give a longer run time for any given job. The same rule of thumb applies where higher voltages are concerned; high voltage tools will drill larger holes faster, improving the all-important return on in investment.
Drill Driver
Cordless drill drivers typically have two primary functions; they are used for drilling holes in wood, plastic and metal, and the variable clutch function makes them suitable for driving screws accurately into various materials. Depending on the nature of the work, drill drivers around 14.4v with a minimum of 2.0Ah batteries will be suitable for most home improvers.
Combi Drill
Combi drills offer the same drilling and screw driving features as drill drivers with the additional feature of hammer action to allow the drilling of masonry, brick and concrete. Typically an 18.0v tool with 2.6Ah batteries is adequate for most applications, but tools with higher voltages and higher capacity batteries are available for situations where the workload is geared towards drilling larger holes in masonry.
SDS Rotary Hammer
SDS plus rotary hammers are available from various manufacturers from 14.4v up to 36v. These tools are designed primarily for the repetitive drilling of holes in concrete and masonry. Through the use of a small piston a much higher impact blow is delivered to the drill bit, which is held in place securely by an SDS plus chuck rather than a three jaw chuck. This means that larger diameter holes can be drilled much faster in masonry, etc. than they would be by a combi drill.
As with most power tools, the more you invest the more you will get. Particularly for avid DIYers, spending a little bit more can often make a significant difference to the performance and flexibility of the tool, dramatically improving the return on investment over the working life of the drill.
