Osborn OSB33137 4" Knot Wire Cup

The Osborn OSB33137 is a 4 inch knot wire cup brush, .014 inch wire, 5/8-11 arbor hole.

The .014 inch wire is the specification worth reading against the rest of this range, and it identifies a middle ground that people skip past.

Wire gauge is the aggression scale. Across the Osborn cups and wheels here it runs .008 for fine crimped cleaning work, .014 in the middle, and .020 for heavy knot stripping. The reflex is to buy the heaviest, on the reasoning that more is better. It is not: a .020 knot cup on light material gouges it, throws more wire, and does the job worse than a lighter brush would.

At .014 in a knot configuration this is a cup that removes without tearing — light rust, scale, coatings, and weld cleanup on material that will be seen afterward.

The 5/8-11 arbor is the threaded angle grinder spindle and it is the fitment to check. This is the standard for angle grinders across the industry, and it is not the same as the 2 inch arbor hole on bench grinder wheels — those are different machines entirely.

Steel wire means carbon steel work only; stainless needs a dedicated stainless brush or it picks up carbon that rusts later.

Verify rated speed against the grinder. Wear a full face shield.

Brand

Osborn

SKU

OSB33137

Category

Abrasives

Weight

1.3 lbs

Dimensions

8.50 x 2.50 x 1.25

Price

$54.00

Availability

In stock

Rating

4.27 / 5.0