If your job is in construction, then there will be times when you would need an angle grinder. This tool is ideal for grinding welds to a smooth finish, cutting pipe for plumbing, severing bolts, and chopping rebar for reinforcing concrete. It is also good for removing paint or rust, cutting concrete, stone, and ceramics and for preparing surfaces for painting. Other industries including auto bodywork use it to polish automobile exteriors.
The tool itself relies on an electric motor that power a set of gears that rotate the head. The head itself is configured at a 90-degree angle to the motor. A threaded retaining ring clamps the motor onto a wheel.
The grinder also includes a safety guard that commonly covers the rear half of the disk. It can be rotated to alter the spark and debris path.
The tool is very easy to use. The operator grasps the main body and controls are accessed from a side handle that is mounted either on the left or right of the machine. A switch or trigger is included to send power to rotate the wheel. A button is also present that locks the trigger so that you don’t have to keep your finger on it to keep the machine working. A spindle lock is included that prevents any movement when you’re changing wheels.
The benefit of the grinder is the assortment of different wheels that are designed for different kinds of cutting that can be attached.
The wheel size and the power of the motor determine the capability of the grinder. The size assigned to the grinder refers to the maximum wheel diameter it can accommodate.
Heavy-duty angle grinders fall into the 7-inch to 9-inch range. There are also 4-1/2- and 5-inch grinders that are more commonly used for do-it-yourself chores.
The machine comes in a variety of horsepower, amps, watts and rpm combinations.
Typically, reference to horsepower is given for the larger angle grinders. A well-rated 9-inch angle grinder generates about 5-horsepower or more. Although that may not sound like a lot, but that is actually equivalent to a big gas lawnmower.
Amps are referred to typically for 4-1/2-inch angle grinders. Amperage refers to the electrical load on the motor. An easier way to look at it is: the more amps, the more power. Angle grinders that are rated above 10 amps are quite powerful and is probably as much power as one would need.
Although manufacturers of angle grinders don’t refer to wattage very often, it concerns the motor’s power output. The more wattage, the better.
RPM or revolutions per minute is the rotational speed of the wheel. The maximum RPM for a 9-inch grinder is commonly 6,000 to 7,000. A 4-1/2-inch grinder will commonly have a maximum RPM of 9,000 or more.
There are two styles of angle grinders –- corded and cordless. Which grinder you select is not the issue. It is the power demands you require. The speed of the grinder develops very quickly. The machine draws a lot of current to do this. If you are using a corded machine, the large draw of current isn’t a problem. However, the initial surge can be very draining on a battery.
It takes an angle grinder a few seconds to get up to speed, but once it does, its demand for power decreases. When you’re actually doing work, the power demands between a corded or cordless machine is not an issue. If you’re using a battery- powered grinder, keep in mind that when you start the machine and stop it, the battery will take a hit.
Angle grinders start fast. As a result, they can generate quite a kickback. The kickback can cause the machine to jerk in your hand when you pull the trigger. There are grinders with a soft start feature that reduces that kick.
To exchange a worn disc for a new one, disconnect the angle grinder from its power source, use a factory spanner or improvised spanner to remove the disc, then install a new disc on the drive bolt.
Abrafast.com offers Metabo angle grinders. These machines have overload capacity and does a great job when cutting or roughening metal. Metabo grinders are available for all disc diameters.
There are a number of safety features on the Metabo grinders. For example, the motor on Metabo grinders turn off immediately after you release the switch. If an additional braking system is included, the disc stops within 2 to 3 seconds after switching off.
To reduce kickback when the disc jams in material, the machine includes a Metabo S-automatic safety clutch or an electronic safety shutdown.
The Metabo angle grinder accepts a variety of discs and wheels including diamond-cutting discs, cut wheels, flap discs, fiber discs and cleaning fleeces. There are also steel wire brushes specifically designed for cleaning, deburring and rust removal. We also have special accessories for processing stainless steel.