Product Categories / Mounted Bearings / Pillow Block Bearing / UGSAO311-35

UGSAO311-35

Name: UGSAO311-35 Pillow Block Bearing
Brand: LILY

$76.90 /Each

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Overview
Part Number	UGSAO311-35
Brand: LILY	Interchangeable With: AMI
Bearing Part Number	UG311-35
Housing Part Number	SAO311
Characteristics
System of Measurement	Inch
Bearing Type	Ball Bearing
Bearing Seal Type	Double Sealed
Inner Ring Type	Wide Inner Ring
Mounted Type	Pillow Block Bearing
Shaft Mount Type	Eccentric Collar Locking
Product Series	UGSAO300
Lubrication Fitting Tap	1/8-27 NPT
Dimensions
Bore Dia	2.1875"
Bore Dia Tolerance	-0.0005" to 0"
Hole Width	0.875"
Hole Length	1.375"
Overall Height	6.7031"
Pillow Height	1.4063"
Center Height	3.75"
Whole Length	12.5938"
Hole Ctr-to-Ctr Min	9.5"
Hole Ctr-to-Ctr Max	11"
Width of Inner Ring	3.5"
Width with Eccentric Collar	2.874"
Mounting Bolt Size	0.75"
Material
Bearings Material	AISI 52100 Steel
Housing Material	Cast Iron
Performance
Temperature Range	-30° to 110 °C
Properties
RoHS	Compliant
REACH	Compliant
Lubrication	Required
Weight	19.72 lbs

UGSAO311-35 Pillow Block Bearing data sheet

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What does UGSAO311-35 mean?

UGSAO311-35 is an AMI inch cast iron pillow block unit with a wide inner ring insert and eccentric collar locking, for a 2 3/16" (55.56 mm) shaft. The part number breaks down into 4 segments:

UG: Wide inner ring ball bearing insert, eccentric collar locking, spherical outer ring. Insert part number is UG311-35

SAO: Housing style: cast iron pillow block. Housing part number is SAO311

311: Frame size 311, 300 series (heavy duty)

-35: Bore in sixteenths of an inch: 35/16" = 2 3/16" (55.56 mm)

Note: For inch mounted bearings, the number after the dash is the bore in sixteenths of an inch. For example, -8 is 1/2", -12 is 3/4" and -16 is 1".

Frequently asked questions

What does UGSAO311-35 mean?

UGSAO311-35 is an AMI inch cast iron pillow block unit with a wide inner ring insert and eccentric collar locking, for a 2 3/16" (55.56 mm) shaft. UG = wide inner ring ball bearing insert, eccentric collar locking, spherical outer ring. Insert part number is UG311-35, SAO = housing style: cast iron pillow block. Housing part number is SAO311, 311 = frame size 311, 300 series (heavy duty), -35 = bore in sixteenths of an inch: 35/16" = 2 3/16" (55.56 mm).

What is the bore size of UGSAO311-35?

The bore of UGSAO311-35 is 2 3/16" (55.56 mm).

The housing of pillow block bearing, crafted from iron, is engineered to withstand heavy-load and high-vibration conditions with the structural rigidity and dimensional stability needed to keep the overall mounted bearing assembly performing reliably over the long term.

Shaft retention is achieved through eccentric collar locking in this pillow block bearing unit, which secures the shaft reliably against moderate loads and intermittent vibration — provided the collar is rotated firmly in the direction of shaft rotation and the locking screw is fully tightened — without damaging the shaft surface.

Two 0.75 inch bolts fasten the mounted bearing unit to the mounting surface, providing a secure and stable foundation that suits both new installations and direct replacement applications. A heavy-duty fastener size associated with large-frame pillow blocks, designed to anchor housings that carry significant shaft loads under continuous or demanding operating conditions.

Why choose Iron for the bearing housing?

Because this pillow block bearing is specifically designed for heavy-load and high-vibration conditions, cast iron delivers superior rigidity and dimensional stability where lighter or polymer housings are prone to deformation under load, making it a purpose-built choice for this application rather than a generic substitute.

Why does this bearing use Eccentric Collar Locking to secure the shaft?

Eccentric collar locking works by rotating an offset collar in the direction of shaft rotation until it clamps firmly around the shaft, which makes it well suited to applications where the shaft surface must remain undamaged and load distribution needs to be more even. Its main advantage over other shaft locking methods is a broader contact area that reduces shaft stress, which matters most when the application involves intermittent loads, frequent starts and stops, or softer shaft materials.

How does the 0.75 inch affect installation and compatibility?

The bolt size directly determines whether the pillow block bearing can be mounted onto an existing frame or structure without modification. A 0.75 inch bolt corresponds to a heavy-duty hole pattern associated with large-frame housings carrying significant shaft loads, so when replacing an existing unit, confirming this dimension ensures a drop-in fit. Mismatched bolt sizes may require redrilling the mounting surface or sourcing an adapter plate, adding time and cost to the installation.