Carbide - Coarse grain v's Fine grain

[monoman]

Hiya,

I found an interesting paper on carbide tipped saws.

See "Wear of tungsten carbide tipped circular saws in cutting particleboard: Effect of carbide grain size on wear characteristics" http://www.springerlink.com/content/p8w25m0727310h4m/

Summary In order to study the wear of tungsten carbide tipped circular saws, three kinds of carbide tips (fine, medium and coarse grained ones) were employed, when sawing particleboards. The saw with coarse grained carbide tips showed the longest working life, while the fine-grained carbide tipped saw retained its usefulness for only a short period of sawing. In an experiment using a saw with all three kinds of carbide tips, it was also confirmed that the fine grained tips wore most and the coarse least.

Kinda goes against the perceived wisdom, doesn't it. I'm sure there might be other factors worth considering other than wear rate when buying carbide tipped tools.

Cheers

[BobL]

In an experiment using a saw with all three kinds of carbide tips, it was also confirmed that the fine grained tips wore most and the coarse least.

This is a pity because the finer grained carbides form sharper edges that coarse grained carbide. Some of the fine grained carbide edges approach that possible with M2 steel but both are still some way short of the very finest edges possible with specialised steels.

Another application of carbide in wood cutting is in special chain saw chain where whole cutters or cutter tips are made of carbide. Recently some chains have been released with fine carbide cutter tips but they have suffered the same problems as the circular saw blade tips.