Publishes both the rpm and the meters per second
WORKPRO W124783, 4-1/2 in × 3/64 in, 10-pack
One of only two listings on this shelf to publish a peripheral speed as well as an rpm figure — which is the marking this hub says to read first.
This hub’s introduction says there are two markings that matter on every disc, and the first is the maximum speed. This listing publishes it twice, properly: 13,000 rpm and 80 meters (262 ft) per second. The second figure is the one that actually governs — an abrasive wheel is rated by how fast its edge travels, because that is what the bond must hold together, and 80 m (262 ft)/s is the standard for a reinforced disc. At 4-1/2 in diameter that works out to about 13,400 rpm, so a stated 13,000 is the same limit stated carefully.
The abrasive is named rather than praised: corundum and white alundum, under double fiberglass mesh, at 3/64 in — which is 0.047 in, a true thin cutting thickness. Ten discs at this price is a sensible unit for a workshop that cuts occasionally.
The second marking this hub names is absent, as it is on all nine American listings here. Nothing on the page addresses iron and sulfur content, which is the specification that matters when the wheel touches stainless: a contaminated wheel leaves iron particles embedded in the cut, and they rust. The listing claims stainless suitability six words into its first bullet and never returns to it. Its bullets also sit very close to those of the 50-pack from another brand further down this shelf.
Availability
Read on the day this page was built: $9 at the American Amazon shop.
Read from Keepa on the day this page was last revised; stock and price both move without notice.
Prices quoted in this text were read on 2026-10-07. The live price is at the top of the page.
The questions welders ask
What does 80 m (262 ft)/s mean next to an rpm figure?
It is the real limit, and the rpm follows from it. Abrasive wheels are rated by peripheral speed — how fast the edge travels — because that is what the bond has to survive, and 80 meters (262 ft) per second is the standard rating for a reinforced wheel. At 4-1/2 in, 80 m/s works out at about 13,400 rpm, so a stated 13,000 is that limit expressed conservatively for this diameter. The reason to publish both is that an angle grinder is marked in rpm and a wheel is designed in m/s.
Corundum and white alundum — does the distinction matter?
In principle yes, and the listing does not explain it. Both are aluminum oxide; brown corundum is tougher and suits carbon steel, while white alundum is friable and cuts cooler, which is what stainless wants because heat is what damages it. A wheel bonded with both is a compromise aimed at either. What this hub’s introduction actually asks about stainless is different and absent here: whether the wheel is free of iron and sulfur, which is what prevents embedded particles rusting in the cut.
