4.3 Machines You May Encounter in a Shop Setting
Douglas Rupik, M.Ed., JIW
Common Shop Machines and Their Function
A well-equipped fabrication shop will likely have several metalworking machines. Cutting, punching, and forming machines can make otherwise time- and labor-intensive tasks quick and easy. Machine shop tools also include lathes and mills for subtractive manufacturing.
Cutting machines include cold cutting machines—such as band saws, circular saws, power hacksaws, and shears—and thermal cutting equipment—such as oxy-fuel torches and plasma and laser cutting equipment. These tools may be manual or machine-operated.
Bandsaws may be dry or have a fluid coolant or lubricant system and they may be oriented vertically or horizontally. Take care when changing blades: Be sure to wear gloves, have another person who can help if needed, and be sure the teeth are oriented the correct way in relation to the material to be cut as well as in relation to the drive wheels. Some bandsaw wheels have a flange to keep the blade in place—the back of the blade should rest on this flange, not the teeth. Be sure all guards are in place, and the material being cut is secure.
If the bandsaw requires you to manually feed the piece being cut, be sure that you are not wearing gloves and that if you or the part slips, your hand, fingers, or other body parts will not end up in the blade. Don’t let your various body parts touch the blade. Keep the piece you are cutting flat against the tabletop as you feed it to the blade. Alternately, if you are using the type of bandsaw that cuts a stationary, clamped piece, be sure it is secure and keeps your hands away from the blade.
Circular saws for metal are usually large and cooled with fluid, and the workpiece is clamped. Power hacksaws for metal are configured similarly to a horizontal bandsaw, but the blade is short and reciprocates rather than being a continuous band. Be sure to keep your hands away from the blades of these tools while they are in use. Do not wear gloves or other clothing that may be caught in moving parts.
Shears are used for cutting sheet, plate, and flat bar. Shears usually have hold-down hammers that keep the material flat while the blade cuts, and these can exert enough force to completely crush fingers or hands. Some specialty shears are designed to cut shapes such as angle, channel, and round stock. Coper notchers are special shears for cutting notches in flat, angle stock, coping pipe, and tubing. Do not place your fingers in the area where the blade travels or in any pinch points created by a blade or shear’s cutting action.
Thermal cutting equipment may be handheld or machine-operated, such as a track torch or CNC plasma cutting table. When using oxy-fuel equipment, observe all applicable safety rules and wear appropriate PPE, such as eye protection. When using plasma or laser cutting equipment or a water jet cutter, be sure to follow all manufacturer’s operating and safety instructions. Their high voltages and liquid coolants can create their own hazardous conditions, so use due caution.
Punching equipment is used to put holes in sections of metal. Older equipment may be powered by flywheel, while newer equipment is often hydraulic. Either style can seriously injure you if improperly used, but a hydraulic machine is often considered safer as it may reverse itself mid-cycle when the actuating mechanism (foot pedal or hand buttons) is released, whereas a flywheel powered machine will cycle without stopping. When using this equipment, ensure the punch and die are properly aligned so they don’t break during use, creating a hazard with flying bits and pieces.
Forming machines include presses, brakes, and rollers. This equipment is often used with sheet metal or a plate to bend corners or roll to a radius. Keep hands and fingers clear of the moving parts of the machine and the material itself, as it will move as the machine bends and shapes it.
Presses use pressure to flatten, bend, or shape metal around forms to mold the metal to a desired shape. Brakes are used to clamp sheet metal down and bend the metal to a desired angle. Rollers pinch metal between two rollers and feed it into a third roller that steadily bends the metal into a curved shape. Think of a wringer on an antique clothes washing machine or a paper shredder that pulls sheets of paper in. As you can imagine, fingers will be flattened if you put them into this machine, so take care.
Machine shops commonly have lathes, which spin pieces of metal while stationary blades cut them into various shapes. Milling machines are the opposite: they hold the metal in place while spinning blades cut away metal to form various shapes. Either of these types of machines requires extensive training to safely use, and improper use can result in serious injury such as the amputation of limbs or even death. Do not use them unless you are properly trained.
Safe Use of Metalworking Machines
Metalworking machines in a shop setting are typically heavy-duty and capable of exerting tons of force. These machines require thorough training for operation. Proper use includes setup, cleaning, and basic routine maintenance. Insist on receiving proper instruction from your employer before using them—do not rely on watching a coworker from across the shop or random YouTube videos. As stated before, do not get creative when using power equipment.
Always wear appropriate PPE, such as safety glasses and earplugs, when on jobsites with metalworking equipment. When using equipment with spinning parts—such as a drill press, milling machine, or a lathe—do not wear gloves, baggy sleeves, or loose, dangling hair, clothes, or jewelry. These may become entangled in the machine and draw you into it, resulting in serious injury and death. These machines often rotate at such fast speeds you will not even have time to react if anything goes awry. When clearing chips or shavings from rotating equipment, do not use rags—instead, use compressed air and be mindful that the blown chips and shavings themselves may become hazardous projectiles.
Remember to never use equipment that is damaged and always follow the manufacturer’s instructions on proper use of equipment and tools.
Safe Use of Related Tools
Smaller shop tools such as drill presses, belt sanders, and bench grinders can present similar hazards to their larger counterparts. Their primary hazards include being entrapped in rotating parts and chips, shavings, or hot sparks being thrown at you. As always, receive proper training before using any piece of shop equipment, follow the manufacturer’s instructions, and never use damaged equipment.