Most of the tropical hardwoods contain silica
e
and other minerals more or less. Sawing of these timber
species is sometimes very difficult, since the cutting edges
of the saw teeth blunts quickly. Due to this sawing difficulty some of the timber species of the forest remain unutilised and are never brought to profitable use. Sometimes the
rate of dulling of the teeth is so high that time and labour
consumed in preparation and sharpening of the blades turn
into sheet waste. So, attempts to coat the cutting edges
of the saw teeth with