31 mm OD Bearings | McMaster-Carr

For a more compact machine, these bearings have thinner inner and outer rings than high-load crossed-roller bearings. Route hydraulic lines, electrical wiring, and other components through the inside of the bearing. The rollers face in alternating directions to allow for rigid, accurate motion under any combination of radial, thrust, and moment (twisting) loads. Use in applications where highly accurate motion is necessary, such as machine tools and industrial robots.

Open Bearing—Open bearings dissipate heat more efficiently than sealed bearings.

				Combined Load Cap., lbf
	For Shaft Dia., mm	For Housing ID, mm	Wd., mm	Dynamic	Static	Max. Rotation Speed, rpm	Lubrication	Temp. Range, ° F		Each
For Combined Radial, Thrust, and Moment Load—Open with Steel Ring



		20	31	5	310	290	2,900	Required	0 to 230	1378N31	0000000

Ball Screw/Splines and Bearings

From one compact system, transmit linear or rotary motion or both at once (sometimes called spiral motion). Because of these different motions, these ball screw/splines and bearings create efficient, fluid movements in complex automated applications, such as pick-and-place robots.

The ball bearings move smoothly and precisely, even at high speeds. They're powered independently, so you can drive one bearing at a time or both together to coordinate movements.

The ball screw/splines are hardened on the surface, so they stand up to repeated motion. They’re also hollow, so you can run electrical wiring, compressed air tubing, coolants, or lubricant through their center.

	Spline		Thread						Ball Screw Bearing				Ball Spline Bearing
	Lg., mm	No. of	Lg., mm	Direction, ° F	Thread Direction	ID, mm	Lg., mm	Root Dia., mm	OD, mm	Overall Lg., mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	OD, mm	Overall Lg., mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	Max. Dynamic Torque, in·lbf		Each
1055 Carbon Steel







				16 mm Dia. (Tolerance: -0.018 mm to 0 mm)

				500	6	360	5 to 176	Right Hand	11	500	15.15	32	40	870	1,610	31	50	1,590	2,830	277	4049N13	000000000

Thrust Ball Bearings

For silky-smooth motion, the balls inside these bearings roll nearly friction-free. You'll often find them at the end of a shaft or between a stationary and rotating surface, such as on a propeller or rotary table.

These bearings come as three separate pieces—one cage and two washers. The cage holds the balls in place, while the washers create a surface for the balls to roll on. This design is easy to lubricate, but the oil will attract dust and grime since it's exposed.

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

	OD, mm	Thk., mm	Cage Material	Dynamic Thrust Load Cap., lb.	Max. Rotation Speed, rpm	Temp. Range, ° F	Includes		Each
Steel



	15	31	12	Steel	2,300	8,500	-40 to 240	Two Washers	6681K13	000000

Needle-Roller Thrust Bearings

Bearings

Washers

Small but mighty, our thinnest rolling thrust bearings slot into tight spaces and spin at whirring speeds. Their long, slender rollers support thrust loads and reduce friction in everything from machine tool spindles to gearboxes.

A cage holds the rollers in place. You can install these bearings without washers between hardened, ground surfaces for the thinnest profile. If you’re working with unhardened, unground surfaces, you’ll need two washers for the rollers to run on. This three-piece design is easy to lubricate, but the oil will attract dust and grime since it’s exposed.

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

	Thrust Bearings									Thin Washers
	For Shaft Dia., mm	OD, mm	Thk., mm	Cage Material	Dynamic Thrust Load Cap., lb.	Max. Rotation Speed, rpm	Temp. Range, ° F		Each	Thk., mm		Each
Steel



		18	31	2	Steel	2,140	10,000	0 to 240	5909K95	000000	1	5909K96	00000

Washers for Needle-Roller Thrust Bearings

These hardened steel washers protect softer shafts and housings from the rolling contact of needle rollers. Without them, needle rollers can indent and score unhardened surfaces, leading to premature wear and bearing failure. Positioned between the bearing and each mating surface, these washers distribute thrust loads evenly and extend service life. They adapt needle-roller thrust bearings for unhardened, unground surfaces.

For Shaft Dia., mm	OD, mm	Thk., mm	Washer Material		Each
18	31	1	Steel	5909K96	00000

Linear Bearings for Ball Splines

Combine these bearings with a ball spline to create a compact linear and rotary motion system for applications with fast, complex movements, such as robotics. These bearings move smoothly and precisely even at high speeds along ball splines while grooves on the ball spline transmit rotary power. Clip a retaining ring into the groove on these bearings to position them in your system. Use the keyway and included machine key for attaching your load.

Steel Bearings


	For 4 Splines

										Groove, mm			Keyway, mm
For Spline Dia., mm	For No. of Splines	Overall Lg., mm	OD, mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	Max. Dynamic Torque, in·lbf	Max. Static Torque, in·lbf	Max. Temp., ° F	With Retaining Ring Grooves	Wd.	Dia.	Includes	Lg.	Wd.	Dp.		Each



	16	4	50	31	1,350	2,500	531	973	176	Yes	1.6	29.4	Machine Key	17.5	3.5	2	61145K13	000000

Mounted Linear Bearings for Ball Splines

A flange with mounting holes makes it easy to attach a load to these bearings. Create a compact linear and rotary motion system for robots and other applications requiring complex, fast movements, by combining them with ball splines. These bearings move smoothly and precisely even at high speeds along ball splines while grooves on the ball spline transmit rotary power. Clip a retaining ring (not included) into the groove on these bearings to position them in your system.

Steel Bearings


		For 4 Splines

												Groove, mm
For Spline Dia., mm	For No. of Splines	Overall Lg., mm	Flange OD, mm	Bolt Circle Dia., mm	OD, mm	Dynamic Load Cap., lb.	Static Load Cap., lb.	Max. Dynamic Torque, in·lbf	Max. Static Torque, in·lbf	Max. Temp., ° F	With Retaining Ring Grooves	Wd.	Dia.	No. of Mounting Holes		Each



	16	4	50	50	40	31	1,350	2,500	531	973	176	Yes	1.6	29.4	4	61145K112	0000000

Metric Press-Fit Drill Bushings

Also known as jig bushings, these metric drill bushings fit inside fixture plate holes to precisely guide drill bits, counterbores, reamers, and other cutting tools. They improve accuracy so that your drilled holes and cuts are consistent from part to part. Known for their versatility, drill bushings are also used as spacers, shims, and machinery bushings. These bushings are made of hardened, ground steel that holds its shape and resists wear, so they last for many cycles without needing to be replaced.

All bushings have a chamfer on the outside that centers the bushing as you place it into the hole. Press into place with a manual or hydraulic press. Since the bushing is sized slightly larger than the hole for an extremely tight fit, it’ll stay put permanently. These are ANSI Type PM bushings—also known as headless bushings—which means you don’t need to counterbore the hole to mount them flush.

They also have an internal chamfer that makes it easy to insert bits, pins, and punches without damaging the bushing or misaligning tools.

Don't see the size you need? Additional sizes are available.

DIN 179—DIN 179 bushings meet dimensional and material standards that make sure they're compatible with other parts and tools. Although DIN 179 is no longer an active standard, it's still a common reference point for designers.

						Tolerance, mm								Each
	OD, mm	Lg., mm	Internal Chamfer	For Drill Bit Size, mm	For Drill Bit Size Decimal Equiv.	ID	OD	Lg.	Drill Bushing Type	Material	Hardness	Specs. Met		1-5	6-11	12-Up
25 mm ID



		31	15	One End	25	0.9843"	0.02 to 0.041	0.017 to 0.033	-0.2 to 0.2	PM	Steel	Rockwell C61	DIN 179	96990A360	000000	000000	000000


		31	50	One End	25	0.9843"	0.02 to 0.041	0.017 to 0.033	-0.3 to 0.3	PM	Steel	Rockwell C61	DIN 179	96990A370	00000	00000	00000
		31	60	One End	25	0.9843"	0.02 to 0.041	0.017 to 0.033	-0.3 to 0.3	PM	Steel	Rockwell C61	DIN 179	96990A380	00000	00000	00000