Rotary hammer drills are primarily designed for heavy-duty masonry work. This work can include boring huge holes into structural concrete, ripping up ceramic tiles, and even light demolition work. They also have the ability to drill through materials such as wood, metal, and plastics.
Although regular hammer drills possess the ability to drill through masonry, the force rotary hammer's exhibit belittles this ability. The difference is in the hammer mechanism of each type of drill. Hammer drills literally on a mechanical hammer action, whereas rotary hammers utilize a pneumatic hammer action.
Each blow from a rotary hammer drill's hammer action is measured in Joules (J). The higher the value of this impact energy, and the higher the 'bpm' value is, the faster a rotary hammer drill can drill through masonry.
There are two different types of rotary hammer drills, and they are each known by the number of modes they possess.
Two-mode rotary hammer drills are named as such for the two modes that possess – rotary drilling and rotary hammer drilling. They are typically the smallest type available, but still pack more than enough punch to accomplish most repetitive masonry tasks with ease. They are also an excellent size for most wood and metal tasks (with the use of a keyed chuck adapter).
Three-mode rotary hammer drills can perform normal rotary drilling, rotary hammer drilling and chiseling – all with the flick of a switch. This chiseling function is a great option for light breaking work and jobs like bathroom renovations.
All of these drills are known by their maximum drilling diameter in masonry. If this specification for a particular model is a 26mm diameter hole, then it will simply be called a '26mm Rotary Hammer Drill'.
One of the more noticeable differences between these drills and other drills is that they are fitted with SDS (Special Drilling System) chucks. These chucks are made out of high quality plastic, and lock masonry-drilling accessories that have an SDS shank into place.
For standard drilling into wood and metal, 13mm (1/2 ") keyed chuck adapters are available with an SDS shank on them, and will slip in and lock straight into an SDS chuck.
These drills feature many different components, and having a sound understanding of these plays an important part in the purchasing process. Knowledge of these parts also aids in the efficient and effective use of the tool. These features include the style of housing and type of handle. It is also important to note that larger rotary hammer drills may not have a reversing feature.
When purchasing, decide what features are most important to you and make sure these are included in your final purchase. The main considerations you should make include how much power you require, the size and weight of the tool, whether you need it to be cordless, and how often you will be using it.
A rotary hammer drill should really be capable of drilling the largest hole into masonry you will ever need to drill. It should also be comfortable to use, and should be of very solid construction. Remember to ensure it is a three-mode model if you require a tool for light chiseling and breaking requirements.
Manufacturers will either direct their products at the DIY or professional market. DIY tools are designed for home use and generally include plenty of features for a very modest price. They also tend to have very generous warranty periods, including replacement warranties. Professional tools are designed for commercial use and are built for durability, performance, and reliability. Their warranty period tend to be much shorter than DIY tools, and are exclusively repair warranties. The main advantage of these tools is that they should well outlive their warranty period, and if they require repair and maintenance spare parts are readily available.
The price of any tool will depend on the quality, capabilities, and features of the model. Bear in mind that at least one of these three elements is commonly sacrificed by manufacturers to reduce the tool's price and increase its sales. After all, price is the most important factor for consumers.
It is important to note that the entire cost of any power tool is not just its initial purchase cost. Added costs can include accessories for the tool to function, maintenance, downtime, and replacement costs. Buying according to your specific needs will help to keep these costs to a minimum.