performance and price are a
function of the details
Oxide – a sharp,
block like material. It has a characteristic which makes it unique
among the various abrasive materials; as you sand, it constantly
fractures and renews its cutting edges. This characteristic is
called friability. Aluminum Oxide is also a very tough material, so
the edges won’t really dull before they fracture. This combination
means that it stays sharp and cuts much longer than the other
It is available in a large range of
hardness’s, which means that there are Aluminum Oxides which are
good for sanding finishes and others which work well for sanding
paints/finishes or even solid surface material.
Carbide – a very
sharp, shard-shaped material. Unlike aluminum oxide, there is only
one grade of silicon carbide. It is harder and sharper than most
aluminum oxides. It is friable, however it will not fracture and
renew its cutting edges when sanding wood so it will dull more
quickly than Aluminum Oxide. Silicon carbide is almost always on
waterproof paper and is usually intended for sanding finishes.
– a blocky natural mineral still used for some sanding applications.
It is not friable and not very tough, so it dulls quicker and cuts
slower than Aluminum Oxide. It tends to burnish the wood surface
which can cause adhesion problems for some of the higher solids
– the hardest of the common abrasives. It comes in shapes that can
include blocks, wedges or shards. Like Silicone Carbide, they do not
fracture and renew their cutting edges when sanding wood, so they
are not friable. Ceramics are extremely tough so they do not dull
easily. Generally you will find ceramics in course grits on cloth
backers, usually in the form of sanding belts.