 This tutorial addresses federal OSHA standards for portable abrasive wheel equipment. More specifically, it addresses the OSHA standards for right angle head grinders. These tools come in a variety of sizes and configurations and can be used to perform many different tasks. But they all share one common feature in their design. The spindle that rotates the abrasive wheel is fixed at a right angle to the main body of the tool. Portable right angle head grinders are powered by a variety of sources including electricity, pneumatic power, and rechargeable batteries. The abrasive wheels for these tools are utilized for different purposes primarily grinding and cutting different materials such as various ferrous and non-ferrous metals, masonry, concrete, and more. But these grinders also present some potentially serious safety hazards including flying sparks, particles of material, and broken pieces of the wheel. OSHA regulations spell out requirements for abrasive wheel grinders that must be followed in order to help prevent injuries. This is achieved through the selection of the right tool for the job, inspection of the grinder and all accessories, utilization of a guard on the grinder, and the use of personal protective equipment. The Federal OSHA regulations for general industry that pertain most directly to the use of portable abrasive wheel grinders can be found in subpart P at 1910.243 which is titled guarding a portable powered tools. For the construction industry, regulations are located in subpart I at 1926.303 titled abrasive wheels and tools. This tutorial will initially focus on the general industry standards listed in 1910-243 starting with paragraph C which covers portable abrasive wheels. Note that there are a few types of abrasive wheels that are specifically excluded from this section of the OSHA regulations including natural sandstone wheels, abrasive coated disc, and small abrasive wheels, cones, and plugs that are typically used with other types of grinders. So be certain to follow the manufacturer's instructions for the use of these excluded items to ensure worker safety. The first step when you are going to be using a portable abrasive wheel grinder is to select the right size tool for the job. Some portable grinders are relatively large in size and are better suited for heavy use over an extended period of time, whereas smaller grinders are better suited for light to moderate use on a sporadic basis. One important thing to be aware of is that all abrasive wheels available for use on these tools are not the same. Some are made specifically for grinding materials whereas others are intended for cutting materials. You can typically get information about the intended purpose of a wheel by looking at its label. Furthermore, wheels are typically made to be used on one particular type or class of material or materials. For instance, this particular abrasive wheel is intended for use on metal or steel whereas this wheel is intended for use on concrete or masonry. Use of an abrasive wheel for purposes it is not intended can cause wheel breakage and should therefore be avoided. Abrasive wheels are also rated for a maximum operating speed, usually expressed in RPMs. So refer to the label on the abrasive wheel you choose to use to determine its rating, then compare that to the rating for the portable grinder you will be using, and make certain that the abrasive wheels rating equals or exceeds that of the tool. Also make certain that the maximum wheel size listed on your grinder is compatible with the size of the abrasive wheel you have selected to use. Using a wheel that is larger in diameter or thickness than intended for your grinder could result in a wheel breaking apart when you run the grinder. Using too large a wheel could also prevent you from installing the protective guard that came with your grinder and that can be very hazardous. One more thing to watch for is the size of the arbor on your abrasive wheel. This is the hole located in the center of the wheel. Trying to force a wheel with too small an arbor onto the spindle of a grinder can cause the wheel to crack, and using a wheel with an arbor that is significantly larger than what is designed for the spindle on your grinder can cause the wheel to become unbalanced and break apart. Before conducting any type of inspection of your grinder, always de-energize the tool and secure the plug. This also applies before you perform any kind of maintenance or adjustment of your tool as well as every time you install a new abrasive wheel. Make certain that you maintain exclusive control of the plug at all times you are handling the grinder during these activities. If for some reason you cannot maintain control of the plug or if more than one person is going to be working on the tool, secure the plug and lock it out for your company's lock out tag out procedures. When visually inspecting your grinder before use, always make sure to look for any parts that are broken or missing. Also make certain the on-off switch operates properly and check to see if any bearings are worn out or loose. You should also look over the power cord to identify any damage along with the plug on the power cord. Make certain the ground pin has not been broken or removed on grounded models. If you do find any defect with the tool that makes it unsafe to operate, immediately take it out of service and tag it so no one tries to use it. Then have the tool repaired for the manufacturer's instruction. It is also important to thoroughly inspect the abrasive wheel before installing it on the tool as well as after any event that could cause damage such as dropping the wheel or the tool onto the floor or other surface. Abrasive wheels in use will eventually become worn to the point that they are no longer usable and may even start to break apart if use is continued. Also abrasive wheels are subject to cracking or breaking, especially when they are handled improperly or the tool is dropped. Abrasive wheels can also become deteriorated when exposed to water or environments with high moisture levels. That is because the abrasive wheel will actually absorb the moisture which causes the adhesives binding the abrasive materials together to weaken. So always store spare abrasive wheels in an area free from water and high levels of humidity. One commonly overlooked procedure OSHA requires to be performed on abrasive wheels before mounting to the tool is to sound the wheel. This simple test checks for cracks and similar defects that may otherwise go unnoticed. To perform this test, place the abrasive wheel on a non-metallic object such as a wooden dowel or you can even use your finger. Then lightly tap the wheel with a non-metallic object such as the wooden handle of a screwdriver approximately three quarters of an inch from the upper edge of the wheel. Then listen to the sound it makes. A wheel that is free of crack should reverberate which creates a tinging sound. This procedure is often called the ring test. Then rotate the wheel one quarter of a turn and repeat the test for a total of four times. While a good wheel should make the tinging sound, a wheel that has a hidden crack or similar defect will make a dead thud sound. Remember, a ring is an indicator of a good abrasive wheel whereas a thud indicates a bad wheel. Before mounting an abrasive wheel to the tool, you should also make certain the flange or other bearing surface of the wheel and the tool's bearing surfaces and retainer are free from foreign matter such as small metal shavings or similarly sized particles. Failure to remove such matter can cause the wheel to become unbalanced or even crack when the wheel is tightened into place. Manufacturers of right angle head grinders provide a guard to be used with their tool. The purpose of this guard is to deflect hazards such as sparks and particles of materials being cut or ground as well as pieces of a broken wheel away from the operator. Therefore it is important to make sure the guard is adjusted to the proper position which is between the operator and the wheel. This protective guard is crucial to prevent injury to the operator and is easily adjustable from one position to another as needed depending on the requirements of the task being performed. There is one exception to the use of a guard in OSHA's portable abrasive wheel standard and is related to internal grinding operations where the abrasive wheel is completely enclosed inside of an object during internal grinding operations. As a last line of defense against flying sparks, material particles and fragments of a broken wheel OSHA requires the operator of a portable abrasive wheel grinder to utilize personal protective equipment or PPE to protect not only their eyes but also their face. Therefore the operator must always wear approved safety glasses or goggles that meet the OSHA requirements as well as an approved face shield. The operator may also need to wear appropriate gloves to protect their hands from flying sparks and particles as well as from hot or sharp surfaces on the material being cut or ground. Depending on the type of materials being worked on and the length of time involved, grinding and cutting operations may also produce excessive amounts of particulate in the air that could be hazardous to breathe as well as potentially harmful levels of noise. So always follow any procedures your company may have in place for the use of a respiratory protection device or hearing protection devices when operating portable abrasive wheel equipment. The OSHA regulations for general industry that apply to the inspection of portable abrasive wheel equipment covered in this tutorial including the often overlooked ring test can be found in these sections of the OSHA CFR. And the guarding requirements for portable abrasive wheel equipment can be located here while the general requirements for assessing the need for personal protective equipment to be utilized while operating this equipment are found here. And here are the OSHA construction standards applicable to inspection of the equipment and accessories as well as guarding and personal protective equipment. Of course OSHA regulations cannot address every single hazard associated with portable abrasive wheel equipment. It is imperative that you become familiar with and follow the manufacturer's instructions for the tool and accessories that you will be using. Instructions commonly recommended by manufacturers include but are certainly not limited to the following. Firmly hold the tool with two hands when first depressing the on switch. Because the grinder has a tendency to twist due to the torque created you could drop or lose control of the tool. Do not grind or cut near flammable or combustible materials nor on any container that have held these materials. That is because the sparks could create a fire or cause an explosion. And always store your tool and accessories in a designated area to protect them from accidental breakage as well as exposure to excessive moisture. So in review it is important to make sure you always select the right tool for the job as well as the right abrasive wheel for the material you will be cutting or grinding. Then inspect them thoroughly before first use as well as after any event that may have caused damage. Always install and properly adjust the manufacturer's guard provided with your abrasive wheel equipment to deflect flying objects away from your body. And be certain that you always wear required personal protective equipment needed to minimize your chance of being injured. By following these steps you can help your company or organization comply with OSHA standards and manufacturer's recommendations. But more importantly this can make the difference between your going home and as good a shape as when you came to work or not.