Woodworking machine guarding - Frequently asked questions
This page contains frequently asked questions on woodworking machinery guarding
When can the riving knife and top guard be removed on a table saw?
The top guard and riving knife can only be removed when performing rebating, grooving or trenching. These tasks generally afford the operator with some protection from the workpiece whilst the task is being performed. Operator must refer to the manufacturers instructions for the use and adjustment. Model instructions for the safe operation of specific woodworking machines are available in AS 1473.2 - 2001.
When cutting plywood, MDF or other panel board on a circular saw bench or panel saw, can the riving knife be removed.
A riving knife is a blade of high grade steel with a smooth surface set behind and in line with the saw blade. Its main purpose is to prevent the sides of an incomplete cut from closing on the up-running part of the saw blade thereby reducing the risk of the workpiece being thrown back at the operator. This hazard is commonly known as a 'kickback'.
The riving knife also affords a measure of protection against the contact with the teeth when the operator or the person assisting the operator removes the workpiece from the back of the saw.
There is no difference in the likelihood of a kick back occurring when panel boards are being cut compared to solid timber therefore the riving knife is not to be removed unless trenching, grooving or rebating or in accordance with the manufacturer's instructions.
I have been told that mutton chop guard or dogleg guard on surface planer do not comply with the Australian Standards is this correct?
The Australian Standards define that surface planers shall be guarded by a fixed guard, an adjustable guard or an automatic guard. Therefore, the type of guard provided by the manufacturer should comply with AS 1473.6 - 2005.
Bridge guarding is the most effective form of guarding on surface planers however over the years changes to machine design has seen the introduction of a number of types of guards including swivel guards or mutton chop guards (for longer machines telescopic guards are available to cover the table gap). The bridge guard should be easily adjustable horizontally as well as vertically without the use of a tool. More importantly, the correct adjustment and use of the guards in accordance with the manufacturer's instructions is the issue not the type of guard.
What are the guarding requirements for radial arm saws?
The radial arm saws can be used for a number of operations including trenching, crosscutting and ripping. The type of guarding required is dependant of the operation that is being performed for example; when cross cutting is being performed the radial arm shall be fitted with an adjustable side guard and a return device. Refer to the manufacturers instructions to ensure the radial arm saw is adjusted and maintained correctly.
What are the guarding requirements of beam saws?
The guarding requirements for a beam saw are provided in Australian Standards 1473.3-2001.
Are all bandsaws required to have brakes?
No. Some bandsaws are fitted with electric or foot operated brakes these devices should be regularly tested and maintained in accordance with the manufacturers instructions. These devices slow the rotation of the bottom wheel of the bandsaw to reduce the stopping time of the bandsaw.
Is there a requirement to have a clear guard on a panel saw so I can watch the blade cutting?
No. There are no requirements to have a clear top guard for panel and bench saws.
The workpiece is supported by the side fence therefore the operator should be ensuring that the workpiece is making contact with the side fence and that the hands are out of the path of the workpiece and the saw blade. Further information can be found in AS 4024.1 -2006 Safety of Machinery series.