Grinding Safety 211

abrasive

A material made up of hard, sharp particles for cutting tiny chips from a workpiece. Abrasives are formed into wheels for use in grinding operations.

American National Standards Institute

ANSI. A private, nonprofit organization that coordinates voluntary standards and systems. The American National Standards Institute sets standards for grinding safety in ANSI B7.1.

ANSI B7.1

A document published by the American National Standards Institute (ANSI) describing the necessary standards for grinding safety. ANSI B7.1 is the basis for OSHA standards regarding grinding safety.

balance

The distribution of weight across all parts of a grinding wheel. Wheels must be balanced to run smoothly.

balance stand

A device for testing the balance of a grinding wheel before installing it on a machine. A balance stand provides a level surface for determining where an out-of-balance wheel is heavy.

bond

Material that holds together the abrasive grains that make up a grinding wheel. Bonds can be glass-like vitrified bonds, or organic materials like rubber or shellac.

brittle

Easy to break. Brittle objects break when subjected to a sudden blow.

canvas

A strong, heavy fabric used in PPE. Canvas protects operators from sharp material.

chips

An unwanted piece of material cut from a workpiece by a tool. Chips are usually small metal shavings or particles.

clearance

An intentional amount of space left between two components. In grinding, clearance is the specific amount of space left between the wheel and the workpiece to avoid damage or poor quality.

computer numerical control

CNC. A type of programmable automation, directed by mathematical data, which uses computers to carry out various machining operations. Computer numerical control is a self-contained system that executes program instructions to guide machine tool components, perform processes, and manufacture parts.

coolant

Fluid applied to prevent damage to a tool or workpiece by absorbing heat from an operation and by lubricating operation components. Coolants can be mixtures of water, oil, and synthetic fluids.

dampness

The quality of being slightly wet. Dampness can break down grinding wheel bonds.

fire-suppressant gas

A gas, typically carbon dioxide, which displaces oxygen to smother fires. In grinding, fire-suppressant gas is used to extinguish fires caused by friction between a grinding wheel and workpiece.

friction

A force that resists motion between components in an operation. Increased friction raises the heat in an operation and can cause damage.

gloves

A type of PPE worn on the hands to reduce the risk of injury. Gloves should always be worn when handling chemicals or sharp objects.

goggles

A type of PPE that fits tightly on the area over the eyes. Goggles protect the operator’s eyes from flying debris, dust, and liquid splashes.

grinding

The use of an abrasive to cut the surface of a workpiece and change its shape. Grinding operations commonly use abrasive grains bonded into the shape of a wheel.

grinding fluid

A liquid used to cool and lubricate the grinding wheel and workpiece during grinding. Grinding fluids can be composed of water, oil, or synthetic compounds, depending on the needs of the process.

grinding wheels

A round cutting tool made of abrasive grains held together with a bond material. Grinding wheels cut tiny chips from a workpiece for a fine surface finish.

guidelines

OSHA recommendations to follow a particular practice or method. Guidelines do not incur penalties for noncompliance.

hazards

A source of danger, normally as a result of unsafe actions or workspaces. Hazards in grinding include using a damaged grinding wheel or leaving grinding fluid on the floor around a machine.

humidity

The presence of water vaper or moisture in the air. Humidity can break down grinding wheel bonds.

interlocking doors

A set of doors that engage with one another by overlapping or fitting together to form a tight lock. In grinding, interlocking doors cover a grinding area to protect the operator from flying debris and fluid splashes.

kilometers per hour

kph. How far an object travels, in kilometers, in one hour. In grinding, the velocity of a wheel’s periphery is typically 129 kph.

leather

Heavy fabric made from animal hide. Leather is used in PPE to protect operators from sharp or hot material.

lockout/tagout

A method of protecting employees by preventing accidental machine startup through proper locking and labeling of machines during maintenance. Lockout/tagout is the common term for OSHA's Control of Hazardous Energy Standard.

lubricates

Reduces friction between components in an operation. Lubrication prolongs tool life and part quality by reducing heat damage.

m/s

Meters per second. A measurement of speed that describes the distance in meters that a point on a grinding wheel travels in one second. M/s depends on the spindle rpm and wheel circumference.

machine guards

A shield or cover over hazardous areas on a machine to prevent accidental contact with body parts or to prevent debris, such as chips, from exiting the machine. In grinding, machine guards include wheel guards and interlocking doors.

machine safeguards

A device or machine component used to prevent operators from contacting hazards. In grinding, wheel guards, interlocking doors, and fire suppressants are common machine safeguards.

mallet

A hammer with a large head, usually wood or rubber. A mallet is typically used for striking another tool.

meters per second

m/s. A measurement of speed that describes the distance in meters that a point on a grinding wheel travels in one second. Meters per second depends on the spindle rpm and wheel circumference.

miles per hour

mph. How far an object travels, in miles, in one hour. In grinding, the velocity of a wheel’s periphery is typically 70 mph.

Occupational Safety and Health Administration

OSHA. The federal agency that enforces safety and health legislation in the United States. OSHA helps employers reduce injuries, illnesses, and deaths in the workplace.

operators

A person trained to operate a piece of machinery. Grinding operators oversee and perform grinding operations.

OSHA

Occupational Safety and Health Administration. The federal agency that enforces safety and health legislation. OSHA helps employers reduce injuries, illnesses, and deaths in the workplace.

periphery

The outer edge of the grinding wheel. Typical grinding operations take place on the grinding wheel's periphery.

personal protective equipment

PPE. Any item that workers wear or use to prevent injury in the workplace. Safety glasses are common personal protective equipment.

PPE

Personal protective equipment. Any clothing or device worn to minimize exposure to hazards and prevent injury. In grinding, common PPE protects hands, arms, and eyes.

pressure

Physical force applied continuously to an object. Too much pressure can damage machines and workpieces, and present danger to operators.

revolutions per minute

rpm. A speed measurement that tracks the number of times a tool, workpiece, or machine component rotates in one minute. Revolutions per minute generally measures the speed of a machine spindle.

ring test

A manual test used to detect damage or cracks in grinding wheels. A ring test will produce a clear, metallic tone when performed on an undamaged wheel.

safety glasses

A type of PPE worn over the eyes to protect the operator’s eyes from flying debris. Safety glasses can have prescription or nonprescription lenses.

screwdriver

A tool used to fasten and tighten screws. Screwdrivers have a handle on one end and a blade on the other, which corresponds to the head on the screw.

sensors

A device that detects changes in physical conditions such as heat or pressure. A sensor alerts operators to hazardous conditions, or engages automatic safeguards.

sfm

Surface feet per minute. A measurement of speed that describes the distance in feet that a point on a grinding wheel travels in one minute. Sfm depends on the spindle rpm and wheel circumference.

shields

A type of PPE worn over the entire face. Shields protect the operator’s face and eyes from flying debris and liquid splashes.

solvents

A liquid that dissolves certain materials. Solvents are often used to clean grease and other difficult-to-remove impurities from machines and tools.

sparks

A tiny fragment of the grinding wheel or workpiece made incredibly hot from the friction of the grinding process. Sparks can burn an operator or ignite oil-based grinding fluid.

standards

OSHA policy on a particular practice or method. OSHA standards have the same power as law, and noncompliance can result in fines and other penalties.

surface feet per minute

sfm. A measurement of speed that describes the distance in feet that a point on a grinding wheel travels in one minute. Surface feet per minute depends on the spindle rpm and wheel circumference.

velocities

The combination of an object’s speed and direction of motion. Unlike speed, velocity always implies a direction.

velocity

The combination of an object’s speed and direction of motion. Unlike speed, velocity always implies a direction.

wheel guards

A protective cover secured over a grinding wheel to protect workers from broken wheels or debris. Wheel guards are required by OSHA.

workpiece

The material being worked on by a tool. In grinding, tiny particles of the workpiece are removed by an abrasive wheel.