A mitre saw is a circular saw mounted on a frame, fixed to a rotating cutting table to make various cuts across the grain of timber. The saw may have a slide action, allowing cuts on much wider boards. Without a slide action, it is also known as a chop saw, or cut-off saw.
While this guidance has not been updated to reflect current work health and safety legislation (the Health and Safety at Work Act 2015 and regulations), it may still contain relevant information and practices to keep workers and others healthy and safe.
Please read this guidance in conjunction with all relevant industry standards that apply to you as a PCBU. This guidance will be progressively reviewed and either updated, replaced with other guidance, or revoked.
There are several types of power mitre saws:
- Standard mitre saw: has a fixed vertical pivot with rotating cutting table, allowing horizontally angled (or mitred) cuts while the blade remains vertical.
- Compound mitre saw: has a rotating vertical pivot, allowing the cutter head and blade to tilt (or bevel) sideways in addition to the horizontally rotating table. This allows vertical and horizontal angled cuts, as well as cuts angled on both planes.
- Sliding compound mitre saw: a compound mitre saw with horizontal sliding arms for the cutter head, allowing cuts on much wider boards.
- Dual compound mitre saw: similar to a sliding compound mitre saw, but its blade and motor can tilt both left and right, providing more flexibility for cutting complicated angles, such as those required for crown moulding.
Mitre saws are often used for cutting long pieces of timber to length, and may be used to cut an angle on the end of a length of timber. When a mitre saw is used for cutting short lengths, the timber may be clamped on the saw’s table, and the blade pushed through the timber.
Mitre saws do not allow the blade to turn parallel to the back fence, so they cannot perform rip cuts.
Figure 1: Mitre saw
- Entanglement from contact with the blade
- Contact or impact from moving timber
- Slips, trips & falls
- Contact, impact and entanglement from unexpected movement (during maintenance, cleaning & repairs)
Personal protective equipment (PPE)
- Ear protection
- Eye protection
- Dust protection
Task – Present timber to the saw
Entanglement from contact with the blade
- Deep cuts or amputation
- FIX guarding. Replace guards if damaged.
- FIT the teeth below the spindle with a peripheral guard that automatically lifts to clear timber as the operator lowers the blade.
- USE clamps to eliminate the need for reaching to the blade.
- DO NOT feed the workpiece into the blade or cut “freehand” – the workpiece MUST be fixed, and clamped or braced by your hand.
- NEVER cross your hand over intended line of cutting.
It is very dangerous to support the workpiece “cross-handed”, that is, holding the left side of the workpiece with your right hand.
Contact or impact from moving timber
- DO NOT cut more than one piece at a time.
Multiple workpieces cannot be sufficiently clamped or braced, and may attach to the blade or shift during cutting.
Other (non-mechanical) hazards
- Risk of fire or explosion – sparks may ignite fumes
- DO NOT USE saws in damp or wet locations.
- DO NOT USE saws near flammable liquids or in explosive atmospheres.
- Hearing damage or loss
- REDUCE noise levels by isolating machines or enclosing within noise barriers.
- ASSESS noise levels.
- ARRANGE hearing screenings.
- ALWAYS WEAR hearing protection.
A safe noise level over an eight hour day is 85dB(A). A mitre saw may exceed this noise intensity.
- Eye irritation or damage
- Breathing problems, lung damage or cancer
- Worsening of existing health problems
- USE dust extraction equipment to minimise dust getting in the operator’s breathing zone.
- ALWAYS WEAR eye protection.
- ALWAYS USE respiratory protection.
Slips trips and falls
- KEEP up-to-date housekeeping procedures.
- KEEP the areas around saws clear of slip and trip hazards.
Task – Maintenance, cleaning & repairs
Contact, impact or entanglement from unexpected movement
- Deeps cuts or amputation
- LOCK-OUT all power supplies before maintenance, cleaning and repairs.
- ARRANGE regular inspections by a competent person.
- REMOVE or LOCK-OUT saws that fail inspection, and DO NOT USE until repaired or replaced.