When using conventional steel saws in stonemasonry, A-weighted noise levels of over 102 dB can be generated from the impact of each blade segment on the stone and by the mechanical vibrations exciting the blade as it rotates at high speed.
Standard blade (left), laminated blade (right)
A number of alternative blades are available. One range includes a laminated blade which absorbs much of the energy by damping the mechanical resonance. The internal construction consists of a layer of copper, sandwiched between two skins of high-tensile steel. The laminated blades are not generally as strong as traditional solid steel blades and are intended for step cutting only.
Another product uses a steel blade which has a series of S-shaped cuts made by laser. These cuts are sealed by cold-rolling the blade. Copper rivets may be added at the base of each gullet. This treatment restricts the propagation of sound waves through the surface of the blade. A laser-cut blade should last as long as a standard blade and is sufficiently robust to be used for full-depth cutting. Generally a 600 mm diameter laminated blade can only be retipped once, whereas a laser-cut blade can be retipped almost as many times as a conventional one.
Maintenance of both types of blade does not require any special skills beyond those needed for traditional blades.
600 mm diameter: standard blade £55, laminate £115, laser-cut £130. (1995)
Measurements taken with these 'quiet blades' during the cutting of similar stone samples show a reduction of between 10 to 12 dB on conventional blade cutting.
Cutting dense sandstone on an ASM profile cutter - straight cut @ 1200 rpm (37 m/s)
Photographs courtesy of Smiths Limestone Limited. Blades supplied by Asahi Diamond Industrials UK Company Limited.