54.9994mm ID Bearings | McMaster-Carr

Smoother than smooth—the balls inside these bearings roll nearly friction-free. You’ll often find them on rapidly rotating parts, from the whirring chuck on a power drill to the spinning shaft on an electric motor.

Shielded—The balls are covered just enough to keep out large particles while allowing air to pass through and dissipate heat.

Steel—Strong and wear resistant. However, these bearings are best for dry environments since moisture will cause them to rust.

ABEC Rating—Bearings with an ABEC rating meet industry tolerance standards established by the Annular Bearing Engineers Committee (ABEC). They're rated on a scale from 1 to 9. The higher the rating, the tighter the tolerance. Bearings rated ABEC 1 or 3 are precise enough for most applications. If your application consistently runs at high speeds or requires high accuracy, consider bearings rated ABEC 5 or higher, since they generate less friction and heat.

							Temp. Range, ° F
	For Shaft Dia., mm	For Housing ID, mm	Wd., mm	ABEC Rating	Dynamic Radial Load Cap., lb.	Max. Rotation Speed, rpm	Min.	Max.	Inner Ring Type	Bearing Trade No.		Each
Shielded







				Steel

				55	100	21	1	9,750	6,300	-20	230	Standard	6211-2Z	00000000	000000


				55	120	29	1	16,000	5,600	-20	230	Standard	6311-2Z	00000000	00000