Alternative Saw Blades

Using an alternative saw blade designed to reduce noise can help lower the risk of hearing loss. 

Description:

Circular saws are commonly used in the construction industry and have a wide variety of applications.  Although they can make work quicker and easier, there are several hazards associated with their use.  One of these is exposure to hazardous levels of noise.  Several manufacturers now offer alternative saw blades that are designed to minimize noise exposure for the operator and other people in their vicinity.  Most of these blades have a vibration dampening component on or inside the body of the blade.

Even if a saw blade is not explicitly marked as quiet, there are several things you can look for that will help reduce your exposure to noise while cutting.  Blades with a very thin kerf, i.e. cutting thickness (Figure 1) and blades with a higher number of teeth will generally be less noisy.
Figure 1. Side view of a circular saw blade
 
However, it’s important to keep in mind that blades with a high tooth count may generate higher levels of dust or silica.  If possible, operate your saw at the lowest rpm that is practical for the work you are performing.  Keep the blade as sharp as possible and maintain the saw regularly.  Blades with diamond or carbide teeth produce less noise, stay sharper longer, and can reduce maintenance costs.  If possible, clamp your workpiece.
 
The following saw blades were designed to operate more quietly than traditional blades:
 
 
MK Diamond MK-925DSLX Supreme Grade Silent Core Blade
Price: $407.00 (verified 12/30/18)
Diameter: 14”, 20”, and 24”
Materials: brick, block, and other masonry
 
Source: www.mkdiamond.com
 
 
 
Hilti DS-BB Super Premium Diamond Saw Blade
Price: $280.00 (verified 12/30/18)
Diameter: 14” and 20”
Materials: brick, block, some types of stone, and general masonry.
Source: www.hilti.com
 
 
 
IQ Ultimate Silent Core Masonry Blade
Price: $270.00 (verified 12/30/18)
Diameter: 14”
Materials: general masonry
Source: www.iqpowertools.com
 
 
 
Makita T-02537 Ultra-Premium Segmented Diamond Blade
Price: $291.00 (verified 12/30/18)
Diameter: 14”
Materials: concrete, asphalt, granite, and general masonry
 
Source: www.makitatools.com
 
 
 
Tenryu Silencer Series
Price: $60.00 (verified 1/22/19)
Diameter: 6.5" - 12”
Materials: wood (crosscutting, finish cutting, general purpose)
 
Source: www.tenryu.com
 
 
 
Diablo Steel Demon
Price: $62.00 (verified 1/22/19)
Diameter: 8" - 14”
Materials: ferrous metals
 
Source: www.diablotools.com

Risks Addressed:

Repeated overexposure to noise causes permanent hearing loss and ringing in the ears (tinnitus).  It has also been associated with hypertension and other cardiovascular diseases (Girard et al, 2015).

The Occupational Safety and Health Administration (OSHA) requires that workers’ 8-hour exposure (also known as LAeq) remain under 90 decibels, while NIOSH has recommended that it remain under 85 decibels. NIOSH’s recommendations are more protective and preferred for maximum hearing conservation. Table 1 shows how long a worker can safely be exposed to different levels of noise (measured in A-weighted decibels, or dBA) according to both OSHA and NIOSH criteria.

 

dBA

OSHA

NIOSH

80

32 hours

>24 hours

85

16 hours

8 hours

90

8 hours

2.5 hours

95

4 hours

47.6 minutes

100

2 hours

15 minutes

105

1 hour

4.7 minutes

110

30 minutes

1.5 minutes

115

15 minutes

28 seconds

120

7.5 minutes

9 seconds

125

3.8 minutes

3 seconds

Table 1

 

Many circular saws, miter saws, and table saws can produce noise as high as 95-115 dBA.  Using NIOSH criteria, a worker could only operate a 115-dBA saw for 28 seconds before their hearing began to sustain permanent damage.


How Risks are Reduced:

Saw blades that are designed to reduce the risk of hearing loss rely primarily on three mechanisms to dampen the vibrations that cause noise:
 
 
1. Laser-cut slots 
 
Source: www.leitztooling.com
 
Some saw blades have several curved or S-shaped slots cut into the body of the blade.  These slots are sometimes pre-filled with a softer material such as brass, copper, or resin. The placement and design of these slots absorbs and dissipates vibrations moving throughout the blade.
 
 
2. “Sandwich” core
Source: http://publikationen.dguv.de/dguv/pdf/10002/12352.pdf
 
Saw blades with a sandwich core, or a vibration dampening core, typically have a thin layer of flexible material (sometimes referred to as "viscoelastic" material) sandwiched between the plates that make up the body of the blade.  This material absorbs and dissipates energy and vibrations, increasing saw blade stability. 
 
 
3. Carbide teeth
 
Source: www.infinitytools.com
 
The teeth of a saw blade are the only part that makes contact with the workpiece.  The sharper the teeth, the cleaner and quieter the cut. Carbide (tungsten carbide or titanium carbide) is harder than steel and stays sharper longer. Most types of carbide teeth can be re-sharpened.  Some masonry saws also have diamond grit embedded in the teeth for cutting/grinding especially hard materials.  
 

Regardless of the type of saw blade, there are several steps you can take to reduce vibrations when using any electric saw. Keep your saw in good working order and maintain it regularly.  Make sure that the collars (or washers) that hold the blade in place fit snugly.  Check your saw for arbor runout, or uneven rotation of the arbor that rotates the blade. Always keep the blade as sharp as possible.


Effects on Productivity:

Quieter saw blades work by dampening the vibrations caused by saw operation.  Reducing this vibration results in a cleaner, more uniform cut and reduces the likelihood of rework.


Additional Considerations:

Gas-powered saws are usually louder than electrical saws. If using a gas-powered saw, consider switching to a different type of saw in addition to using a quieter blade.

Regardless of the type of blade or equipment, employers must provide hearing protection devices to workers who may be overexposed to noise. Although all hearing protectors are assigned a Noise Reduction Rating (NRR), most workers do not receive the labeled amount of noise reduction (Murphy et al, 2013). The best way to determine hearing protector effectiveness is to perform fit testing, which uses a computer program and special headphones to gauge the actual noise attenuation of hearing protectors worn by workers.

 


Contributors:

Sara Brooks, MPH, CPH - CPWR The Center for Construction Research and Training

Bruce Lippy, Ph.D. - CPWR The Center for Construction Research and Training

Edward Zechmann, MS/PE/INCE Bd. Cert. - NIOSH

 


Hazards Addressed:

  • Carpentry
    • Build or install roof trusses
    • Construct forms for concrete footings and foundations
    • Construct suspended ceiling interior systems
    • Cut boards and panels
    • Install and finish wood flooring
    • Install cabinets, countertops and moldings
    • Install doors, windows and associated hardware
  • Drywall, Glass & Floor Coverings
    • Cut and install metal framing for windows and atriums
    • Cut boards and panels
  • General Labor
    • Construct and remove sidewalk forms
    • Operate pavement cutters and concrete grinders
  • Masonry, Tile, Cement & Plaster
    • Cut bricks, blocks, stone, concrete, tile or terrazzo
  • Pipes & Vessels
    • Cut and drill holes in structures prior to pipe installation
    • Cut, thread, hammer and bend pipes and vessel tubes
    • Disassemble and remove damaged or worn pipe
  • Reinforced Concrete
    • Build traditional formwork and lay down decking
    • Cut or bend rebar
    • Perform surface grinding or cutting
  • Residential Construction
    • Cut boards and panels
    • Install and finish flooring
    • Install cabinets, countertops and moldings
    • Install doors, windows, attic access and associated hardware
    • Install framing and roof trusses
    • Install wood, metal or engineered floor and ceiling beams
    • Perform surface grinding or cutting
  • Roofing
  • Sheet Metal & HVAC
    • Cut, file, grind, deburr, buff and smooth assembled parts
  • Structural Steel
    • Drill, grind and saw materials
    • Fabricate metal structures in shop and field

Availability

Hilti
To obtain information, visit DS-BB Super Premium Diamond Saw Blade or contact 1-800-879-8000

Tenryu
To obtain information, visit Silencer Series or contact 1-800-951-7297 info@tenryu.com

Makita U.S.A., Inc.
To obtain information, visit T-02537 Ultra-Premium Segmented Diamond Blade or contact 1-714-522-8088

Diablo
To obtain information, visit Steel Demon or contact 800-334-4107 customerservice@diablotools.com

IQ Power Tools
To obtain information, visit Ultimate Silent Core Masonry Blade or contact 1-888-274-7744

MK Diamond Products, Inc.
To obtain information, visit MK-925DSLX Supreme Grade Silent Core Blade or contact 1-800-421-5830 customerservice@mkdiamond.com

Return on Investment

To calculate the return on investment (ROI) for your specific application, please visit our Return on Investment Calculator. While a specific ROI example has not been developed for this particular solution, the ROI Calculator provides a useful tool and guidance on how to generate your own on investment analysis.