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4.20 Machine Guarding Methods

4.20 Machine Guarding Methods

These guidelines provide general information on machine guarding. Examples of places on machines that expose an employee to injury are pulleys, flywheels, pinch points, belts, gears, shafts, spindle ends, nuts, or any other potentially hazardous projections. Fixed enclosure guards, which completely enclose a hazardous operation point, are preferred to all other types; they provide maximum protection, require minimum maintenance, are suitable for high production and repetitive operations, and can be constructed to suit many specific applications. Fixed enclosure guards can also effectively control dust and chips. Any machine part, function, or process that may cause injury must be safeguarded.

Follow these guidelines for guarding machines:

  • Provide one or more methods of machine guarding to protect the operator and other employees from hazards created by operation points.

  • Where possible, attach the guards to the machine. If not possible, attach them where they will provide the greatest protection.

  • A qualified person should design and construct guarding devices that will ensure no part of an operator’s body will be in a danger zone.

  • Construct and mount each machine so it will not “walk,” or move, while operating at full speed.

  • Use abrasive wheels only on machines with safety guards.

  • Keep power and operating controls within easy reach of the operator while at a regular work station. The operator should not need to reach over a machine to adjust controls.

  • Use only approved tools that are specifically designed to move material in and out of machines. These tools should allow workers to easy handle the materials without placing a hand in the danger zone. Tools do not replace required guarding methods.

  • Whenever engineering controls are not available or are not fully capable of protecting the employee, operators must wear protective clothing or personal protective equipment.

  • The abrasive wheel guard on a bench grinder should be mounted to maintain the proper distance with the wheel. The tongue guard should be positioned at a maximum of one-fourth of an inch (6.35 mm) from the abrasive wheel. The tool rest should be no farther than one-eighth of an inch (3.18 mm) from the abrasive wheel.

  • The strength of the fastenings should exceed the strength of the guard.