As I browse my angle grinder purchasing options, finding the right torque is my No. 1 priority.
When comparing drills, grinders, circle saws and other rotating tools, available torque is the important factor. Torque is a way of measuring how much force directed at an object can make it rotate. In other words, it is the turning force or turning power.
The more torque, the better able your grinder, drill or circle saw is going to be able to get through thick, hard material. If you are only going to be drilling or grinding wood and other softer material, torque is of less concern. However, as I was shopping for a grinder for use on steel, stone and wood, I paid particular attention to torque.
An important element in torque is the speed at which it is available. While you can use any drill with a screwdriver bit, a low torque drill will make a poor power driver. You need torque at slow speeds to neither strip nor over-drive a screw. The same holds true for a grinder. High speeds are great for cutting steel or concrete or buffing a surface, but removing a welding bead or smoothing a concrete face calls for a lighter touch. High torque at slow speeds can be helpful to keep from marring the rest of the surface. A variable-speed or multi-speed angle grinder can make a big difference in ease of use and versatility.
I know I want the highest amps, the most rugged drive system and the highest torque angle grinder with a variable speed that I can justify, but what about other features? Handling ease with top and side handles for two-handed operation is important for safety and control. Size and weight are also important, as is ease of adjusting safety guards. Grinding creates a lot of debris and fine dust. How protected is the motor?
All of these features are important. Finding the best tool for my needs will require trade-offs in all of these areas. Now comes the hard part: deciding on my purchase.