0.248" OD Bearings | McMaster-Carr

When shoulders come up short, use these shims to extend the shoulder length on your screw. Wiggle the shims over the threads and up to the existing shoulder to create the exact shoulder length you need. Use them to create more space for bearings, pulleys, and sprockets, or extend the length of travel along the shoulder.

You can stack multiple shims to achieve the exact shoulder length or space you need.

Stress-Resistant Spring Steel—These shims are harder and hold their shape better than carbon steel. Use them for high-stress applications, such as leveling heavy machinery. They're best for dry environments since moisture will cause them to rust.

	ID	ID Tolerance	OD	OD Tolerance	Min. Hardness	Pkg. Qty.		Pkg.
Stress-Resistant Spring Steel





	For 1/4" Diameter Shoulder

	0.005"	-0.0005" to 0.0005"	No. 10	0.171"	0" to 0.011"	0.248"	-0.002" to 0.002"	Rockwell C40	25	91140A231	000000
	0.015"	-0.00075" to 0.00075"	No. 10	0.171"	0" to 0.011"	0.248"	-0.002" to 0.002"	Rockwell C40	50	91140A243	00000
	0.032"	-0.0015" to 0.0015"	No. 10	0.187"	0" to 0.011"	0.248"	-0.002" to 0.002"	Rockwell C40	25	91140A255	00000

Shims for Ball Bearing Outer Rings

Boost bearing efficiency and lifespan. Often used on motor shafts, these shims evenly distribute the load between multiple bearings by creating space between their outer rings. This prevents excessive pressure on any single bearing, maintaining proper alignment for smooth operation and reduced wear.

You can stack multiple shims to achieve your exact thickness, but stacking more than four may cause them to shift. Remember, fewer shims are better, so a couple of thicker shims are more stable than a bunch of thin shims.

18-8 Stainless Steel—The choice for wet and outdoor environments, these shims resist rust. However, they’ll corrode or pit when exposed to salt water and chemicals.

Super-Corrosion-Resistant 316 Stainless Steel—Superior to 18-8 stainless steel, these shims won't degrade when exposed to harsh weather, salt water, and most chemicals.

Brass—With a warm, polished look, these shims are often chosen for their appearance. Similar to 18-8 stainless steel, brass is corrosion resistant enough to stand up to wet environments.

	For Bearing
	Trade No.	ID	OD	ID	ID Tolerance	OD	OD Tolerance	Min. Hardness	Choose a Thickness	Pkg. Qty.		Pkg.
18-8 Stainless Steel



		R1-4, R144	5/64", 1/8"	1/4"	0.167"	0" to 0.005"	0.248"	-0.005" to 0"	Rockwell B70	0.003" , 0.005" , 0.007" , 0.01" , 0.02"	25	93574A200	000000


		Super-Corrosion-Resistant 316 Stainless Steel



				R1-4, R144	5/64", 1/8"	1/4"	0.167"	0" to 0.005"	0.248"	-0.005" to 0"	Rockwell B90	0.005" , 0.007" , 0.01" , 0.02"	10	91182A130	00000


				Brass



						R1-4, R144	5/64", 1/8"	1/4"	0.167"	0" to 0.005"	0.248"	-0.005" to 0"	Rockwell B70	0.003" , 0.005" , 0.007" , 0.01" , 0.02"	10	92409A300	0000