Flange Bearing

A flange bearing is a bearing unit that bolts flat against a wall or machine frame, with the shaft passing through at right angles: an insert bearing sits in a cast iron flange housing, so no separate bearing seat has to be machined. FULI is a flange bearing manufacturer and supplier in Linqing, Shandong, and our factory makes the UCF square flange units on this page; our bearing manufacturer page shows the other types we make. The size table above lists every flange model on this site with its shaft diameter and insert width. Below: how the flange types differ, how to read the dimensions, and what to send with an inquiry.

Flange bearing range and series at FULI

The UCF 200 series is a light duty flange series. Each unit is a UC insert, a deep groove ball bearing with a spherical outer ring and two set screws that lock the inner ring to the shaft, in a square cast iron flange with four mounting holes. The spherical seat lets the insert align itself, which takes up small mounting errors between the shaft and the wall. The balls between the inner and outer ring reduce friction and carry the radial load, plus a moderate axial load in either direction.

Model	Shaft d (mm)	Bolt spacing J (mm)	Insert width B (mm)	Mounting bolt
UCF205	25	70	34.1	M10
UCF208	40	102	49.2	M14

Both follow the JIS B 1557 standard sizes until our factory drawing is added. The flange bearing dimensions page covers the UCF and UCFL 200 series together.

Flange ball bearing types: 4-bolt and 2-bolt

A flange ball bearing unit is named by its housing. The UCF is a square flange with a bolt in each corner, so the fixing load is shared by four points. The UCFL is an oval flange with its bolts on one line; it needs less width on the frame, which suits narrow members and side plates. See the 2 bolt flange bearing page for the two-bolt type.

Segment	Meaning in UCF205
UC	Insert bearing with set-screw locking and spherical outside diameter
F	Square flange housing, four bolt holes
2	200 series (light duty)
05	Bore code: 05 × 5 = 25 mm bore

The insert is the same one used in a pillow block of the same size: a UCF205 and a UCP205 both carry a UC205. If you need a flange style or series that is not listed on this site, send the designation and we will confirm it with the quote.

Other flange housings follow the same pattern. The UCFC is a round flange with a pilot that centres in a bored hole, as on the UCFC208. The UCFB is a triangular, 3-bolt flange. The UCFA is an adjustable flange type.

Flange bearing block dimensions

A flange bearing block is sized by the shaft diameter d, the bolt hole spacing J, the flange length L and the insert width B. On a square flange, J is the distance between the centres of two adjacent bolt holes and L is the side length of the flange. The insert width B tells you how far the unit extends along the shaft.

When you replace a unit, measure the shaft and the bolt spacing first. Two units with the same designation can differ in bolt spacing if one is made to JIS and the other to ISO 3228; for UCF208, JIS gives 102 mm and ISO 3228 gives 101.5 mm. Each model page gives the full dimension set, the mounting bolt size and FULI’s catalog load ratings.

Inch bore flange bearings

Our factory also makes inch bore versions of these units. The number after the dash is the bore in sixteenths of an inch, so UCF205-16 fits a 1 inch shaft and UCF208-24 fits a 1-1/2 inch shaft. The housing is the same as the metric unit of the same size; only the bore is different. The inch sizes are listed on the UCF205 and UCF208 pages and on the inch bore pillow block bearing page, with each bore in inches and millimetres.

How to select a flange bearing

1. Shaft size. The bore code times five gives the bore in millimetres for codes 04 and up.
2. Mounting surface. Measure the bolt pattern and the space around the shaft. A wide wall takes the square UCF flange mount; a narrow member or side plate takes the oval UCFL.
3. Load. The 200 series is light duty. For heavy loads and shock, choose the 300 series, such as the UCFL321, or a larger housing. Very heavy shafts move to spherical roller bearings or tapered roller bearings in split housings, see the spherical roller bearing range.
4. Environment. Dust, water, washdown or heat decide the seal, the lubrication interval and the housing material. Cast iron is the standard; pressed steel flanges suit light loads, and stainless steel or thermoplastic housings resist corrosion.

Flange bearing vs flanged ball bearing

The same words cover two other products. A flanged ball bearing, often a miniature bearing such as the F or MF series, has a thin flange on the outer ring that sits against the face of a bore and locates the bearing in a small machine. Flanged sleeve bearings are plain bearings or bushings with a collar, made of bronze or a composite with PTFE; they have no rolling element and suit slow, oscillating motion. This page covers mounted flange units, a ready-to-fit bearing housing with the insert inside. Like pillow block bearings, they are fitted where a separate seat would be costly to machine.

Specifications FULI supplies

Item	FULI specification
Series	UCF 200, metric and inch sizes
Insert	UC type, sealed, spherical outside diameter, set-screw locking
Insert material	GCr15 chrome bearing steel, rings and rolling elements
Housing	Cast iron, square flange, bolt hole in each corner
Precision	P0 standard
Radial clearance	C0 standard; C3 on request
Supply	Complete unit; insert or housing quoted separately on request

To get a quotation, send the designation (for example UCF205 or UCF205-16), the quantity per size and the destination port to sales@fuli-bearings.com or use the request a quote form.