Noise in engineering

These pages aim to provide simple, easy to follow guidance and advice on the risks of exposure to noise, specific to engineering industries, and gives possible solutions to some common noise problems in engineering.

What you must do

Where it is reasonably practicable to do so, employers must reduce noise exposure by means other than the provision of hearing protection.

Common noise reduction measures

  • design changes to a process, component or machine
  • segregating noisy machines from employees
  • damping machine parts to reduce vibration
  • isolation of machinery using anti-vibration mountings
  • use of silencers, for example on pneumatic exhausts
  • enclosure of noisy machines
  • use of screens or barriers between noise sources and employees
  • provision of noise refuges for employees
  • fitting sound absorbing materials to work areas
  • when re-equipping, specify noise requirements and purchase quiet equipment
Activity or process Established noise control methods Further information (links)
Power Presses
Typical noise levels with no controls:
95-115 dB(A)		 Methods include:
  • Provide anti-vibration mounts;
  • Cut a shear or skew on blanking tools;
  • Partial acoustic enclosures fitted around tools give significant reductions;
  • Provide damped / isolated machine panels to reduce radiated noise. Existing guards can also act as enclosures by covering or lining panels with sound deadening materials, inserting polycarbonate windows where necessary;
  • Full acoustic enclosures around machines can protect others not working on the machine;
  • Dynamic absorbers designed to bond to a flywheel can reduce noise vibrations caused by the operation of the clutch and the impact of the tooling;
  • Fit sound absorbing panels to ceilings of the room to reduce spread of noise to other areas of the work shop;
  • Line bins and chutes with rubber, pvc etc;
  • minimise component drop heights;
  • Ensure machinery is properly maintained.
 Examples: Absorption of vibration Absorption panels in ceiling Acoustic screens Damping a conveyor chute Reducing flywheel noise Tooling modifications
CNC Punch Presses
Typical noise levels with no controls:
95-100 dB(A)		  Methods include:
Some of the methods used for a power press (above) will be equally practical for a CNC punch press. In addition to these:
  • use proportional / optimal punching force technology;
  • tool carousels and punching areas can be enclosed.
  • Use non-metallic clamps or fit noise absorbing pads
  • Separate the machine from the operator.  Provide acoustic screens / enclosures;
  • Minimise the operators time spent near the machines.  Automated sheet loading/unloading systems can help with this;
  • Choose tools carefully.  eg using a 30 x 6 mm tool instead of an 80 x 6 mm tool for a 'slitting' operation may reduce the noise level by up to 5 dB(A). As a general rule, the smaller the surface area of the tool, the lower the noise;
  • Carry out periodic inspections and necessary maintenance on machines and noise control measures, to ensure that they continue to work effectively;
Examples: Acoustic enclosure Fitting absorptive measures to machines Anti-vibration mounts High speed blanking press
Metal cutting saws
Typical noise levels with no controls:
90-95 dB(A) free running
Over 100 dB(A) when cutting, particularly with high speed saws cutting non-ferrous materials		  Methods include:
  • Reduced noise circular saw blades may be available;
  • Damp the saw blade, especially on saws that exhibit 'resonance' when idling.  Damping discs or plates and laminated blades can help. On a pendulum cross-cut saw, for example foam can be added inside the existing top guard to absorb sound and at the same time produce a damping effect on the saw blade;
  • Select the correct saw blades for the operation and replace blunt blades (or regrind the cutting edge if applicable);
  • clamp work pieces and fit dampers (eg pads) to clamps;
  • Use noise / vibration absorbing material on the surface of the feed table;
  • Enclose or partly enclose the cutting area with suitable absorptive material, or remove the saw to a separate room to protect others not working on the saw;
  • Turn the saw off when not in use;
  • Carry out periodic inspection and necessary maintenance on saws to ensure that they continue to work effectively. Ensure bearings etc do not wear out and the saw blade is properly balanced;
 Examples: Remounting a saw

Noisy processes in engineering

A person's overall noise exposure may come directly from an individual machine, but noise from other machinery or processes elsewhere in the workshop may also contribute to this. This means that as well as a machine operator people at risk include those working nearby, for example, maintenance fitters, cleaners, fork lift truck drivers and shop floor supervisors.

Below are some examples of typical everyday noise levels and noise levels for a selection of engineering processes where no steps have been taken to reduce noise are given below:

  • Grinding on a pedestal grinder 90-95 dB(A)
  • Discharging metal objects into metal bins 85-95 dB(A)
  • General noise level in fabrication shop 85-95 dB(A)
  • Hammering steel 95-100 dB(A)
  • Guillotining 95-100 dB(A)
  • Multi-spindle automatic turning 95-105 dB(A)
  • Circular sawing metal 95-105 dB(A)
  • Pressing - blanking 95-110 dB(A)
  • punch pressing 110-120 dB(A)
  • Riveting 100-110 dB(A)

Inspectors often comment that the noisiest item in a workshop is the radio.

Quicklinks to the HSE noise pages

Do you have a noise problem at work?

If you know you have a noise problem then the section on managing noise risk and specific advice for employers/managers will be useful. The section on how to protect your workers includes help with health surveillance.

Advice and guidance for workers - Worried about your Hearing?

Presses

Grinding machines

Metal cutting machines

Other engineering machinery and processes

See also

Back to top

Is this page useful?

2023-09-11