Angle Grinder

File:Angle grinder.jpeg

4-1/2" Angle Grinder

Safety First Hazard Analysis

Spark spray. Eye protection required. Tool is very loud. Hearing protection recommended. Prevent drawn-in injuries. No loose clothing, loose long hair, or dangling jewelry. Injuries from Kickback/ Breaking Wheels/ Flying Wires. Cuts/ scrapes from sharp cut edges of work. Sparks are a fire hazard - Remove all flammables. Burns from hot workpieces — friction creates heat. Breathing in particulates thrown into the air. The danger of an out-of-control tool — Avoid locking the power switch into the on position whenever possible. Use only 4-1/2” accessories on 4-1/2” angle grinders. Other size accessories won’t fit properly and can break during operation. Rated speed on the accessory must be within the rated speed marked on angle grinder.

Use For	Do Not Use For
Anything ferrous, unless using a disc specified for non-ferrous use. Discs are specific to your process. Metal cutting: cutoff disc Metal grinding: grinding wheel Ceramics/ masonry: diamond abrasive disc/ wheel Surface Cleaning: Wire wheels and cup brushes, Flap wheels, Sanding discs	Do not use disks designed for steel on Aluminum, copper, brass, bronze or similar soft metals (except flap wheel). Soft metals will gum up abrasive cutting / grinding discs designed for steel.

Operation Notes

Extra precaution required for a hand-held tool operating at high rpm’s. This is basic information. Refer to manufacturer’s manual for additional details, especially if you are inexperienced with angle grinder use.

• Always wear safety equipment: Eye protection (safety glasses AND a clear face mask), ear protection, and protective clothing.
• Do NOT wear gloves. This is an A2 Metal Shop Rule, for consistency sake. Gloves can catch, causing the tool to injure your hands. Unplug tool and adjust disc guard as needed.
• Always secure work with clamps or by other means so you can use two hands on grinder to control high rpm’s and torque. Note the rotation direction of the tool and prevent workpiece rotation.
• Watch for climb and kickback while operating the tool. Beware of pinching discs in the workpiece.
• Some angle grinders have lock-on switches, a feature best left unused. An out of control angle grinder that has been locked on is extremely dangerous.
• Understand the disc type needed for your process. The rated speed of the accessory must be at least equal to the maximum speed marked on the power tool. Use only 4 1/2” accessories on a 4 1/2” angle grinder.
• Understand how discs can break in a cut. Check discs for wear and tear. Pieces of broken discs may be ejected at high speeds and cause severe injury. Thin cutting wheels are particularly prone to breakage, so avoid sideways pressure when using them, and avoid deep cuts.
• With grinding discs, grind at an angle, on the edge of the disc, not the flat, not the edge. This produces better grinding results and prolongs the life of grinding discs.
• When temporarily putting the tool down, use the angle grinder’s built-in tool rest, preferably after the disc has stopped spinning.

Basic Operation Instructions

1. Perform a safety check prior to use.
   • Make sure a disc guard and a handle are installed and adjusted for your use. Do not use an angle grinder without these safety and tool control features in place.
   • Do not use damaged discs. Damaged cutting discs and grinding discs can shatter while in use.
   • If using a pre-installed disc, check the disc for damage and make sure it has been properly installed on the tool. Locking flanges must make full contact with the disc.
   • If the cord is damaged, in tag angle grinder out with a red tag, available in the shop.

1. If needed, change the disc.
   • Make sure tool is unplugged.
   • Know the accessories required to fasten your particular disc: Support Flange, Locking Flange, Spanner Wrench. Some discs are hubbed, which means they are threaded and do not need a locking flange.
   • Place the disc on the spindle, press the Arbor Lock button to stop spindle rotation. Use the appropriate accessories to secure the disc.
     • Note that the locking ring has a flat side and a raised side. Use the side appropriate to your disc. Some discs, such as some wire wheels, may need no locking wheel.
   • Tighten with a spanner wrench or an allen wrench. No need to over tighten. The locking assembly will self adjust when the spindle rotates.

1. Secure your work piece, then plug the tool into your power source.
   • To prevent damage to the tool’s cord, always be aware of cord location.

1. Start the tool:
   • Hold the tool firmly in both hands. (There’s usually some minor kickback at startup.)
   • Never start the tool with the disc touching the workpiece. Bring the disc to full speed before starting your angle grinder task.
   • Flip the safety latch and press the paddle to start. (Some angle grinders will have a power switch instead of a paddle.)

1. Use common sense and follow best practice procedures while performing your angle grinder operations.
   • Watch for kickback, climb, and pinched discs. Learn to identify and use the “safe” part of wheels.
   • Throw sparks in a safe direction.
   • Do not force the wheel — let the disc do the work. The application of extra pressure will create extra friction (and heat) that can slow your operation and damage the disc.
   • Pay attention to the angle a disc should be used at. Discs are often labeled for usage.
   • Be mindful of other people in the shop. They should be wearing appropriate protection too, especially eye protection.

Angle Grinding Safety - a must-watch video

Note: For consistency purposes, A2’s Metal Shop does not recommend the use of gloves while operating power rotary tools. This is to prevent drawn-in injuries. Web resources (such as the safety video below) may advocate the use of appropriate work gloves when using an Angle Grinder.

https://youtube.com/watch?v=oJRSkBSb5S8&t=1s

Caution: Aluminum Dust + Rust + Heat = A Thermite Explosion

• All three elements can be readily available in a grinding situation.
• Do not use disks made for steel on aluminum. Aluminum is soft and will gum up the disk, making it less effective.
• If an Aluminum impregnated disk is used on a rusted piece of steel, the heat of grinding can potentially ignite a thermite explosion. If you don’t believe it, Google it! Please, do not create potentially explosive situations in our shop!