NTNUKFS309D1Four-Bolt Square Flange Mounted Ball Bearing Unit, Cast Iron – 45 mm Tapered-Bore Insert, Adapter Sleeve Mount, 53 kN Dynamic

Product Description

What this part is

NTN UKFS309D1 mounted ball bearing unit. Manufacturer: NTN Corporation. Part Number: UKFS309D1. Type: 4-bolt square flanged unit. Bearing Number: UK309D1. Housing Number: FS309D1. Bearing Type: ball bearing. Locking Device: adapter sleeve. Insert Bore: 45 mm nominal, 1:12 taper. Housing Material: cast iron. Housing Construction: 1 piece. Seal Type: contact. Seal Material: nitrile rubber. End Type: open. Performance Class: heavy duty. Dynamic Load Rating: 53.0 kN (11,900 lbf). Static Load Rating: 32.0 kN (7,200 lbf). Weight: 8.40 lb (3.80 kg). Operating Temperature Range: -40 to +250 °F (-40 to +120 °C). Lubrication: relubricatable. Number Of Rows: 1. Design Units: Metric. GTIN: 4547359238679. Country of Origin: Japan.

Housing style and bolt pattern

Housing Style: four-bolt square flange, cast iron, one-piece, in NTN’s heavy-section FS series. Bolt Count: 4. Bolt Hole Spacing: 4.9219 in (125 mm). Bolt Hole Diameter: 0.7500 in (19 mm). Overall Flange Dimension: 6.3125 in (160 mm). Height H3: 4.9213 in (125 mm). Housing Width B1: 1.9690 in (50 mm). Flange Thickness F: 0.2913 in (7.4 mm). Dimension A: 1.7344 in (44 mm). Dimension A0: 2.1406 in (54.500 mm). Dimension A1: 0.7188 in (18 mm). Dimension A2: 0.5469 in (14.000 mm). Dimension A3: 0.4375 in (11 mm). The four holes sit at the corners of a square, so the unit resists moment load in every direction, and the unit bolts to a machine face perpendicular to the shaft with the shaft passing through the flange. NTN’s other flange styles carry the same insert in a different housing: FL is the two-bolt oval flange, FC is the piloted cartridge flange with a register spigot, and the pillow block styles bolt to a base parallel to the shaft.

Bore, adapter sleeve and shaft size

Insert Bore: 45 mm nominal on a 1:12 taper. Locking Device: adapter sleeve. The tapered bore seats on an adapter sleeve, and the sleeve fitted sets the shaft the unit runs on. NTN catalogues UKFS309D1 against three sleeves: H2309 for a 40 mm metric shaft, HA2309 for an inch shaft of 1.4375 in (36.513 mm), and HS2309X. NTN’s own dimensional note records that the sales drawing shows the bore size without the adapter, and that the d dimension is the bore size with the adapter fitted. Drive-up along the sleeve taper both clamps the insert to the shaft and sets its internal clearance.

What these specs mean in practice

An adapter sleeve clamps the insert through a full 360° interference rather than through two point loads, which is what makes this the choice for reversing duty, heavy shock and higher speed. It also lets the unit sit anywhere along a plain shaft, with no machined step, keyway or flat. Dynamic Load Rating: 53.0 kN, Static Load Rating: 32.0 kN — heavy-duty figures for a 300-series mounted ball unit, and the pair a bearing life calculation runs on. Seal Type: contact seals in nitrile rubber, which rub the insert shoulder and exclude dust and washdown water. Lubrication: relubricatable through the housing grease fitting, so service life is extended in place. Operating Temperature Range: -40 to +250 °F. Weight: 8.40 lb. The insert’s spherical outer surface seats in the housing’s matching spherical bore, so the bearing self-aligns to shaft-to-housing angular error as the unit is bolted down.

Quantity and configuration

Unit Quantity: 1 Pc. Cast iron four-bolt square flange housing with its UK309D1 tapered-bore insert and contact seals. The adapter sleeve, locknut and lockwasher are separate catalogue items.

Fitting notes

The sleeve goes onto the plain shaft first, the insert is driven up the taper to its set position and locked, and the housing is then bolted to a flat rigid face, shimmed where the face is uneven. Bolts are brought up evenly so the spherical seat finds its alignment before final torque. Relubrication is through the grease fitting in the housing.

Interchange guidance

The direct interchange is another maker’s four-bolt square flange unit taking a UK309-pattern adapter-sleeve insert at matching flange bolt centres: NSK UKFS309 and the equivalent Asahi, FYH and SNR adapter-sleeve flange units. UCFS309 is a related size in the same housing envelope carrying a straight 45 mm bore insert with setscrew locking, so it fits a 45 mm shaft directly and locks by a different method. UKFL309 and UKF309 carry the same insert in two-bolt oval and standard square flange housings, and UKP309 is the pillow block form. Searchable variants of the number: UKFS309D1, UKFS309, UKFS 309 D1, UKFS-309-D1, UKFS309D1+H2309X, UK309, UK309D1, 4547359238679.