FafnirRCJ-2-15/16Four-Bolt Square Flange Mount Bearing Unit, 2-15/16″ Bore, Eccentric Locking Collar, Cast Iron, Non-Expansion

Product Description

What this part is

Fafnir RCJ2 15/16 four-bolt square flange mounted bearing unit, built by The Timken Company — cast iron housing, wide-inner-ring insert and eccentric locking collar supplied together as an assembly. Timken files it as Fafnir Four-Bolt Flanged Mounted Bearings, Eccentric Locking Collar, Industrial series. Bore / Shaft Size: 2-15/16 in. Insert Bearing: G1215KRRB. Housing Style: four-bolt square flange. Housing Material: cast iron. Locking Method: eccentric locking collar. Closure Type: shroud seal. Series: Industrial. SAP Material ID: 100200624. Design Units: Imperial.

Decoding the designation

R — the Regular, industrial-duty housing series.

C — collar-lock, an eccentric locking collar.

J — four-bolt square flange housing style.

2 15/16 — the shaft size, 2-15/16 in.

G1215KRRB — the wide-inner-ring insert bearing fitted in the housing, catalogued on its own.

Published ratings

Dynamic Load Rating (C): 68,900 N (15,500 lbf) per unit. Static Load Rating (C₀): 44,800 N (10,100 lbf) per unit. The static rating governs on equipment that sits loaded, is shock-loaded while stopped, or indexes rather than running continuously; the dynamic rating feeds an L10 life calculation for continuous rotation.

Mounting data

Bolt Center To Center Length: 152.4 mm (6.000 in). Bolt Hole Size N: 16 mm (0.63 in). Bolt Size: M16. Total Length L: 196.8 mm (7.748 in). Housing Width A: 66.7 mm (2.626 in). Flange Thickness A1: 22.2 mm (0.874 in). Center of Bearing from Housing End A2: 41.9 mm (1.65 in). Dimension B1: 92.1 mm (3.626 in). Dimension S1: 54.8 mm (2.157 in). Dimension D: 161.9 mm (6.374 in). Dimension E: 96.7 mm (3.807 in). Dimension d1: 101.6 mm (4.000 in). The 6.000 in bolt hole spacing and the 3.626 in B1 figure together fix where the shaft centreline lands relative to the mounting face.

What these specs mean in practice

The insert’s extended inner ring carries an eccentric cam face at one end and the collar has a matching eccentric bore. The unit slides onto a plain straight shaft; rotating the collar in the direction of shaft rotation jams the two eccentrics together, and the collar setscrew then locks the collar to the shaft. The grip is distributed over a wide contact arc rather than two point loads from setscrew tips, which is what gives eccentric-collar units their holding power under reversing loads, shock and continuous vibration. The collar is directional and is fitted so that it tightens in the direction the shaft turns. At the 2-15/16 in bore size the four-bolt square flange spreads the mounting load across four fasteners.

Quantity and configuration

Unit Quantity: 1 Pc. One complete flange unit: cast iron housing, G1215KRRB insert bearing, eccentric locking collar and seals assembled.

Interchange guidance

Fafnir is a Timken brand and RCJ2 15/16 remains an active Timken catalogue number. Alternate Part Name: RCJ215/16. Searchable forms: RCJ2-15/16, RCJ2 15/16, RCJ215/16, RCJ-2-15/16. The insert alone crosses as G1215KRRB. Related sizes on the same bore that mount differently: RCJT is the two-bolt flange, RCJO is a four-bolt unit with a different flange outline, RCJC is the concentric-collar version, and TCJ is the same four-bolt style in the light housing series.