Introduction

Portable cut off saws, cut off wheels and drop saws are high noise level machines. They are commonly used in the engineering area for cutting off lengths of metal. Noise levels produced are in excess of 100 dB(A) at the operator's ear. Good hearing protection is required. 

Maintenance

• Ensure blade cover does not rattle. Tighten if necessary. Also examine clamping accessories for wear. 
• Bearings in this type of machine need constant attention. Regular servicing of the machine with inspection of the carbon brushes and motor/gearbox bearings can save permanent and irreparable damage. If the bearings become worn excessive play becomes evident in the main shaft, which can jam work making the tool unsafe. To test for wear, grab the blade and attempt to wiggle it from side to side. There should be little or no play. 

Noise control

• Use special sound dampened blades instead of grinding disks for aluminium cutting. 
• Where possible, use machine outside, but beware of noise annoyance to adjacent spaces. 
• Use mobile screens to isolate area from adjacent work areas. 
• Try using rubber matting under the machine if used on a bench top. This will help prevent vibration transmission through the bench. 

Operator control

• Clamp all work securely prior to cutting. This is a safety procedure that also helps reduce noise. 
• Do not use excessive pressure when cutting. Allow more time and feed the blade into the cut. 
• Try to keep work at arms length from your body. The increased distance helps reduce noise at your ear.  

Alternatives

• Use power hacksaws, metal cutting band saws or hand held reciprocating hack saws. Some slow cutting saws use a lot of leverage and a large induction motor. When purchasing cut off saws specify the type with the large induction motor as these are quieter.  

Introduction

Circular saws are widely used for sizing timber prior to machining. Large panel saws are used for cutting chipboard, ply and melamine coated material. The noise level produced by this equipment is influenced by the types of blade used and the hardness of the material being cut. Noise levels produced by fixed circular saws can be in excess of 100 dB(A). Hearing protection is usually required. 

Maintenance

• Maintain tool in good operational condition, replacing worn bearings and belts. 
• Tighten any loose parts such as belt and blade safety guards. 
• Ensure that the saw is firmly bolted in place and free from vibration. Always mount such tools on a concrete floor, as timber floors tend to vibrate. 
• Keep blades sharp 
• Use the correct type of blade with teeth spacings to suit the task.   

Noise control

• Use quieter saw blades. 
• Use saw in areas isolated for the purpose, such as a machine room. 
• When mounted on a wooden floor use rubber mountings  under the machine.  

Operator control

• Feed in timber gently, letting the blade cut at its own speed. Keep the timber flat against the bed of the saw and avoid twisting motions. Use gentle pressure and allow the blade more time to cut. This also extends blade life. 
• If the noise level of saw is known, schedule work so not to exceed the daily exposure standard. 

Alternatives

• Investigate alternative methods for performing the work. 
• For small jobs use a sharp hand saw to lessen noise exposure. 
• If the noise levels produced by the saw are less on softwoods than hardwoods, use softwoods if practicable. 
• Use pre cut timber (order the correct size).  

Introduction

Hand held power circular saws are used for rapid cutting of timber on site. The noise levels of power saws can exceed 110 dB(A). Hearing protection is required as the exposure standard can be exceeded in a short period of time. 

Maintenance

Maintain tool in good operational condition. These tools normally have a brush type electric motor that runs at high RPM. The noise levels produced by the tool relate directly to the condition of the motor and blade. 

• Inspect and replace any worn bearings and brushes. Excessive sparking in the motor could indicate worn brushes. 
• To test for wear in the main shaft bearings, grab the saw blade and attempt to wiggle it from side to side. There should be very little play. 
• Worn bearings on this tool can create a safety hazard. Increased play in the main shaft causes the blade to jam in the cut. 
• Tighten any loose parts such as blade covers. 
• Keep blades sharp. 
• Use the correct type of blade with teeth spacings to suit the task.  

Noise control

• Use quieter saw blades. 
• Use saw away from main work areas, or perform sawing operations in an isolated room.  

Operator control

• Feed in blade gently, letting the blade cut at its own speed. Keep the bed of the saw flat against the wood and avoid twisting blade. Clamp work to saw stool if possible. Use gentle pressure and allow the blade more time to cut. This also extends blade life. 
• If noise level of saw is known, schedule work so not to exceed the daily exposure standard. 

Alternatives

• Investigate alternative methods for performing the work. A band saw may be suitable or a large docking saw with an induction motor may produce less noise. For small jobs use a sharp hand saw to lessen noise exposure.
• If the noise levels produced by the saw are less on softwoods than hardwoods, use softwoods if practicable. 

Introduction

Band saws are common pieces of equipment in workshops. They are used to cut timber, soft metal and plastics with a good degree of accuracy. The noise levels of a band saw, depending on the blade type and material being sawn, can exceed 85 dB(A), requiring the use of personal hearing protectors. 

Maintenance

• Make sure the blade is running freely between the guide rollers. Check the rollers for adequate lubrication and wear. 
• Check that the belt covers to the flywheel are adequately secure and vibration and rattle are dampened. 
• Ensure that blades are tensioned properly in accordance with manufacturer's instructions. 
• Keep a regular check on the sharpness of the blade. Blunt blades tend to take longer to cut and can burn the work. 
• Check the centre insert in the table. Make sure that it is not loose and does not obstruct the blade. 

Noise control

• Adjust guide rollers to thickness of material being cut. 
• Some guide rollers on older machines may be modified to run quieter. On models where a revolving disk is used to support the blade, the disk can be replaced with a small bearing mounted on a length of rod.

Operator control

• Do not use excessive pressure (eg forcing the wood through). Let the machine cut at its own pace.

Alternatives

• This is generally a quiet machine and should be used in preference to other power tools such as jigsaws and circular saws.