JTEKT-KOYO UK308 Radial Insert Ball Bearing - 35 mm ID, 90 mm OD, 34 mm Width
JTEKT-KOYO UCFL202-J Flanged Housing Unit - 15 mm ID
    JTEKT-KOYO UK308 Radial Insert Ball Bearing - 35 mm ID, 90 mm OD, 34 mm Width
    JTEKT-KOYO UCFL202-J Flanged Housing Unit - 15 mm ID
JTEKT-KOYO UK308 Radial Insert Ball Bearing - 35 mm ID, 90 mm OD, 34 mm Width
JTEKT-KOYO UCFL202-J Flanged Housing Unit - 15 mm ID
JTEKT-KOYO UK308 Radial Insert Ball Bearing - 35 mm ID, 90 mm OD, 34 mm Width
JTEKT-KOYO UCFL202-J Flanged Housing Unit - 15 mm ID
    JTEKT-KOYO UK308 Radial Insert Ball Bearing - 35 mm ID, 90 mm OD, 34 mm Width
    JTEKT-KOYO UCFL202-J Flanged Housing Unit - 15 mm ID
JTEKT-KOYO UK308 Radial Insert Ball Bearing - 35 mm ID, 90 mm OD, 34 mm Width
JTEKT-KOYO UCFL202-J Flanged Housing Unit - 15 mm ID

JTEKT-KOYO UK311 Radial Insert Ball Bearing - 50 mm ID, 120 mm OD, 44 mm Width

  • d 50 mm
  • D 120 mm
  • B 44 mm
  • Open (None)
  • C0 - Normal
Brand: JTEKT-KOYO

Genuine JTEKT-KOYO product, JTEKT-KOYO

$446.39
$446.39
$52.49
Shipping calculated at checkout.
green lightning bolt icon for industrial tools and equipment
18 in Stock Now

Same-day shipping

Order by 3 PM ET for same-day shipping

Buying 20 or more, or need tax exemption?

Request a volume quote

Call Us

(248) 429-9073

Free shipping on orders over $100

Use code at checkout.

Request a quote

Tell us the part number and quantity. We reply with pricing and lead time.

Why Apollo USA

Bearings from Apollo Industries, Oxford, Michigan

Apollo Industries supplies bearings, seals and maintenance tools to businesses across the US, with real people on the phone when you need a part matched.

  • Same-day shipping

    Order by 3 PM EST for same-day shipping.

  • Free shipping over $100

    All orders over $100 ship free by ground with code FREESHIP.

  • 90-day returns

    Hassle-free returns on unused items within 90 days.

  • Price match

    Show us a competitor's advertised price on the same item and we will match it.

  • Expert support

    Support staff available by phone, web chat or email.

  • Need tax exemption or quantity pricing?

    We offer special rates for businesses and bulk orders.

    Contact us

Map of Oxford, Michigan
Oxford, Michigan

Talk to a bearing specialist

(248) 429-9073

sales@apollousa.com

2695 Lake George Rd
Oxford, MI 48370
Request a quote Contact us

Overview

JTEKT-KOYO UK311 Insert bearing

Radial Insert Ball Bearing

JTEKT-KOYO radial insert ball bearings (Y-bearings) are deep groove ball bearings with extended inner rings, convex outer surfaces, and integrated seals. They are designed to be mounted in housings to form bearing units and allow some initial misalignment.

Key features

  • Extended inner ring with locking options
  • Convex outer ring for self-alignment
  • Integrated sealing on both sides
  • Designed for pillow blocks and flange units
  • Easy to install and replace

Specifications

JTEKT-KOYO UK311 dimensions & specifications

Drawing of the JTEKT-KOYO UK311, bore d 50 mm, outside diameter D 120 mm, width B 44 mm B 44 mm D 120 mm d 50 mm
Drawn to scale from the catalog dimensions.
Bearing type
Insert bearing
Bore diameter d
50 mm (1.969 in)
Outside diameter D
120 mm (4.724 in)
Width B
44 mm (1.732 in)
Seals / shields
Open (None)
Internal clearance
C0 - Normal
Weight
3.92 lb
Brand
JTEKT-KOYO
Part number
UK311
UPC / EAN
4549250376429

All specifications

Dimensions

Bore Diameter50 mm
Outside Diameter120 mm
Width44 mm

Properties

MaterialStandard bearing steel
CageSheet steel cage
SealContact seal on both sides
BoreTapered bore (1:12)
Outer ringSpherical
Inner ringWidened inner ring on both sides
Tolerance classTolerance class P0/PN2 / ABEC 1
Temperature range-20 to +120 °C
FixingAdapter sleeve
Scope of deliveryWithout sleeve

Logistics

Product Net Weight1.78

Tools & lubrication

Complete the job for your UK311

Mount it without damage and keep it lubricated. Tick what you need and add it with one click.

Part number decoded

What every part of UK311 means

UK
Insert bearing with a tapered bore (for an adapter)
3
UK 300 insert bearing (adapter sleeve) (dimension series 3)
11
Bore code 11 × 5 = 55 mm (ISO convention)
Decode another part number

Catalogs & documents

Koyo (JTEKT) UK311 catalogs & documents

Official catalogs and data from the manufacturer. They open as PDFs in a new tab.

About the brand

About Koyo (JTEKT)

Koyo, the JTEKT bearing brand, since 1921.

Zenichiro Ikeda founded Koyo Seiko in Osaka in 1921 as a private store that sold imported bearings, and it soon began making its own; in 1927 it commercialized Japan's first tapered roller bearing. In 2006 Koyo Seiko and machine tool maker Toyoda Machine Works merged to form JTEKT Corporation, headquartered in Kariya, Aichi, Japan.

Koyo introduced its HI-CAP tapered roller bearing in 1968 and launched the world's first ceramic bearings in 1984.

Since April 2022 Koyo bearings carry the JTEKT name: the same company, factories and products under one name, JTEKT says. Boxes may read "JTEKT, formerly sold as Koyo", and bearings in new boxes may still be stamped Koyo. From September 2026 new boxes read "Koyo, JTEKT Bearing Brand", and old and new boxes will be on the market together for a while.

Genuine Koyo (JTEKT) product

Shop all Koyo (JTEKT)

  • Founded

    1921

  • Headquarters

    Kariya, Aichi, Japan (JTEKT)

  • Employees (March 2026)

    43,233

  • Sales (year to March 2026)

    ¥1.92 trillion

Known for

  • Tapered roller bearings (HI-CAP, low-torque LFT)
  • Needle roller bearings
  • Ceramic bearings
  • Insert bearing units
Koyo (JTEKT) website (opens in a new tab)

Disclaimer: Apollo Industries is not an authorized distributor, reseller, or representative of Koyo (JTEKT). All Koyo (JTEKT) trademarks and product names are the property of their respective owners. We sell genuine Koyo (JTEKT) products purchased through independent channels.

Apollo USA Bearing Search Tool

Apollo USA Bearing Search Tool

Stop guessing what bearing you need. The Apollo Bearing Index has 98,500+ bearings across 100+ brands — paste FAG 22215-E1-XL-K-C4 and see what every letter means, or search by PN, dimensions, or the machine the bearing lives in (Haas, Mazak, DMG MORI, Caterpillar, Vestas, and 400+ more).

Learn More

FAQ

UK311 questions & answers

What are the dimensions of the JTEKT-KOYO UK311?

The JTEKT-KOYO UK311 has a 50 mm bore (d), a 120 mm outside diameter (D) and a 44 mm width (B). In inches: 1.969 × 4.724 × 1.732 in.

What type of bearing is the UK311?

The JTEKT-KOYO UK311 is an insert bearing.

Is the UK311 sealed or shielded?

The JTEKT-KOYO UK311 is an open bearing (Open (None)): it has no seals or shields.

What internal clearance does the UK311 have?

The JTEKT-KOYO UK311 has C0 - Normal internal clearance.

Is this a genuine JTEKT-KOYO bearing?

Yes. Apollo Industries sells genuine JTEKT-KOYO products, purchased through independent channels. Apollo is not an authorized distributor, reseller, or representative of JTEKT-KOYO.

Do you ship the UK311 the same day?

In-stock orders placed by 3 PM EST ship the same day. All orders over $100 ship free by ground with code FREESHIP.

Can I get quantity pricing or buy tax-exempt?

Yes. Apollo offers special rates for businesses and bulk orders. Use Request a quote on this page or call (248) 429-9073.

Check Out These Related Products

  • BOSCH REXROTH R0530-108-10 (KU-B8-OFK) Ball Transfer Units - 12.6 mm OD, 11.2 mm Width
    $11.96
    $11.96
    $7.02
  • SKF W6305-2RS1/VT378 Deep Groove Ball Bearing - 25 mm ID, 62 mm OD, 17 mm Width SKF box for the 6003 -2RSH/C3 Deep Groove Ball Bearing
    $8.45
    $8.45
    $13.51
  • SKF W6305-2RS1/VT378 Deep Groove Ball Bearing - 25 mm ID, 62 mm OD, 17 mm Width SKF box for the 6203 -2RSH Deep Groove Ball Bearing
    $10.64
    $10.64
    $13.83
  • SKF W6305-2RS1/VT378 Deep Groove Ball Bearing - 25 mm ID, 62 mm OD, 17 mm Width SKF box for the 6305 -2RS1/C3 Deep Groove Ball Bearing
    $18.52
    $18.52
    $27.13
  • SKF W6305-2RS1/VT378 Deep Groove Ball Bearing - 25 mm ID, 62 mm OD, 17 mm Width SKF box for the 6203 -2RSH/C3 Deep Groove Ball Bearing
    $8.18
    $8.18
    $13.83
  • SKF W6305-2RS1/VT378 Deep Groove Ball Bearing - 25 mm ID, 62 mm OD, 17 mm Width SKF box for the 6305 -2RS1 Deep Groove Ball Bearing
    $18.52
    $18.52
    $27.13