NSK3307B2ZRTNGC3Double Row Angular Contact Ball Bearing 35x80x34.9mm Shielded Both Sides Polyamide Cage C3 Clearance

Product Description

What this part is

A double-row angular contact ball bearing on the 3307 envelope: 35 mm bore, 80 mm OD, 34.9 mm wide (1-3/8 inch), shielded on both sides, with a polyamide cage and C3 internal clearance. A double-row angular contact bearing does in one part what a pair of single-row bearings does in two — it takes heavy radial load together with thrust in both directions, and it locates the shaft axially without needing to be matched or set. Typical homes are pump and gearbox shafts, worm drives, agricultural and material handling machinery, and any short shaft where a rigid bearing has to do everything in one position.

Decoding the designation

3307 — ISO double-row angular contact envelope, 35 x 80 x 34.9 mmB — 25° contact angle in this scheme (as also used on the 5307 designation)2ZR — steel shields both sidesTNG — glass-fibre reinforced polyamide cageC3 — internal clearance greater than normal

What these specs mean in practice

Because the two rows are ground into a single pair of rings, the bearing arrives with its axial location built in — no matched pair, no spacer, no drive-up setting. That makes it a genuinely simpler assembly than two opposed single-row bearings, at the cost of a wider envelope and a lower speed ceiling. Shields on both sides retain the factory grease and keep coarse debris out; they are non-contact, so they add almost no friction but they do not seal against washdown or fine dust the way a contact seal (2RS) would. C3 clearance runs looser than normal at rest, which is what you want with a heavy interference fit on the bore or where the inner ring will run hotter than the outer — but a C3 bearing fitted where a normal-clearance one belongs can be noisy and can allow more shaft movement than the design intends. Clearance mismatch causes problems in both directions. The polyamide cage is light and quiet with good high-speed behaviour, but it has a lower temperature ceiling than a steel or brass cage.

Published specifications

Bore: 35 mmOutside diameter: 80 mmWidth: 34.9 mm (1-3/8 inch)Bearing type: double-row angular contact ballContact angle: 25°Closure: steel shields both sides (2ZR)Cage: glass-fibre reinforced polyamide (TNG)Internal clearance: C3, greater than normalRows: 2Thrust capability: both directions

Quantity and configuration

One bearing. No matching, pairing or spacer is required — a single double-row angular contact bearing locates the shaft axially in both directions on its own.

Fitting notes

Mount clean and press only on the ring being fitted; never drive mounting force through the balls. Shielded bearings are pre-greased and are not intended to be relubricated, so do not attempt to prise the shields off to add grease — a bent shield will rub. Use the shaft and housing fits specified for the machine: on a C3 bearing an over-tight bore fit eats into the extra clearance that was the reason for choosing C3. Keep the polyamide cage away from steam cleaning and sustained high temperature.

Interchange guidance

This bearing is referenced as 3307B-2ZR-TNG-C3, 3307B-2ZRTNGC3, 3307 B 2Z C3 and under the older 5307 designation as 5307ZZ — the 3300 and 5300 series numbering both describe the same double-row angular contact envelope. Related but NOT interchangeable: an open 3307 without shields, a 2RS contact-sealed version, a normal-clearance (CN) or C4 version, and a brass or steel cage version, which changes the temperature and speed characteristics. Two single-row 7307 bearings are a related solution rather than a drop-in substitute — the envelope and the setting requirement are different.