Craftsman Hardware | Saw Blade Bore

The saw blade bore, is where the saw blade body, as then attached to the equipment and is a vital area to looked at correctly to ensure a healthy and safety standard is met. Improper attention to the bore, could cause serious injury.

The diameters required when choosing a saw blade are the following:
1. The equipments drive shaft diameter, for minimum diameter.
2. The equipments clamping plate diameter, for maximum diameter.
The bore of the saw blade, must never exceed the clamping plate diameter.
Reducer rings must be used to fill the void between the saw blade body and the equipment shaft,

When a reducer ring is used in the bore of the saw blade body, it is important that the reducer ring does not exceed the saw blade body width. This will ensure that the machines clamping plate, will hold the saw blade upon working.  Failure to use an appropriate width reducer ring for the bore may cause injury.

For example, you have a 165mm Circular Saw, that uses as standard a 1.6mm saw blade body, with a 2.2mm kerf. The machine has a 20mm drive shaft and the clamping plate, a diameter of 28mm.

The key measurements are:
1. Equipment Drive Shaft Diameter of 20mm
2. Equipment Clamping Plate Diameter of 28mm

This can be represented by the following "28x20". Keeping this written down or in mind will help choose a saw blade. 28 representing the MAXIMUM diameter of the saw blade. 20 representing the MINIMUM required.

The saw blade you are looking at, has a 30mm diameter in the exact diameter saw blade required. Using the information from 'Saw Blade Body' the first question you should ask, is how deep do you need to cut? Many lower diameter saw blades, also have a lower diameter bore size available.

So, you have decided that rather than 55mm cutting depth, you only need 30mm cutting depth, and there is a 150mm diameter saw blade with a 25mm bore. Lowering 15mm from the saw blade diameter, will only reduce the cutting depth by the following equation:
SUM (165-150)/2=7.5

So, the cutting depth will be reduced by 7.5mm, allowing still for a 47.5mm cut depth. So, in this instance, a smaller blade can be used. In this case, the 150mm saw blade, has a kerf of 2.8mm, so, you need a reducer ring that takes the 25mm saw blade bore, to the 20mm drive shaft, and a maximum of 2.8mm thickness.