Sanders, Sanding Abrasives and Rotary Tools

Which disc fits which pad

Most listings here are consumables, so match the attachment first. Hook-and-loop discs peel on and off, adhesive-backed ones stay put, and clip-on sheets are cut to size for a pad with clamps. Each works only with the matching pad. Diameter must agree as well: a 5-inch disc needs a 5-inch pad, and its holes should line up with the pad's dust holes. Then choose grit. Low numbers such as 60 remove material fast, 100 to 150 smooth the surface, and 220 and finer prepare it for finishing.

Abrasive material changes how a sheet cuts and how long it lasts. Aluminum oxide is the general choice for wood and metal. Silicon carbide is sharper and brittle, which suits paint, primer and sanding between coats. Sheets in packs also vary in size: a 9 by 11 inch sheet is the common full sheet, which is then cut down for sanding blocks and sanders.

Shanks, collets and wheel speed on powered tools

For the powered tools, check how the work is held and driven. Routers and rotary tools take bits with a fixed shank diameter, commonly a quarter or a half inch on routers, and the collet must match it exactly. Grinders and polishers use wheels and pads with a stated diameter and arbor size, and a wheel's rated maximum speed must be at least the tool's top speed. Cordless models need their own battery and charger, so see whether they are included. Carbide bits last longer in hard materials but chip if dropped.

Questions about Sanders, Sanding Abrasives and Rotary Tools

What grit sandpaper should I start with?

Start coarse enough to remove the flaw: roughly 60 to 80 grit for old paint or rough wood, 100 to 120 for general shaping. Then step up through 150 and 220 without skipping more than one grade, so scratches from the earlier grit disappear.

Can I use any sanding disc on any random orbital sander?

No. Diameter, attachment type and hole pattern all have to match the pad. A 5-inch hook-and-loop disc suits a 5-inch hook-and-loop pad, and mismatched holes reduce dust extraction and clog the paper faster.

Aluminum oxide or silicon carbide: which sandpaper is better?

Neither is better overall. Aluminum oxide is a durable general choice for wood and metal. Silicon carbide is sharper and suits paint, primer, plastics and between-coat sanding, though it is more brittle and wears faster under heavy pressure.