RexnordKCL45-58Two-Bolt Low Base Ball Bearing Pillow Block, 5/8 in Bore, Centrik-Lok Concentric Collar, Cast Iron

Product Description

What this part is

A complete housed ball bearing unit in the two-bolt pillow block style, from the MB Krown Regal Centrik-Lok line, with the low shaft height casting. Bore is 5/8 in (15.875 mm), size code 203. The cast iron housing sits on a foot with elongated bolt slots and carries a corrosion-resistant powder coat. Locking is by a Centrik-Lok concentric collar on a wide inner ring insert.

Decoding the designation

K — Centrik-Lok concentric locking collar construction
C — pillow block with standard backing height
CL — pillow block with low backing height, the shorter base-to-shaft-centre casting
45 — wide inner ring, standard duty series
-58 — inch bore, 5/8 in
Insert bearing number KMB45-58-PA, wide inner ring

Housing style and mounting geometry

Two-bolt foot-mounted pillow block, low shaft height, cast iron. Base to bore centreline 1-1/16 in (26.97 mm), held to ±0.005 in. The base bolt holes are elongated slots, so bolt centres are adjustable from 3-1/8 in (79.40 mm) minimum to 4-1/8 in (104.8 mm) maximum. Overall length 5 in (127.0 mm). Mounting bolt size 3/8 in (M10).

What these specs mean in practice

The 1-1/16 in base-to-centreline height is what defines the fit against an existing frame, and the low CL casting sits lower than the standard KC45 profile of the same bore, which is what suits it to shallow frames and clearance-limited positions. The elongated slots give a full inch of adjustment along the bolt axis, so the block can be traversed to meet a shaft centre that is not exactly on the bolt pattern. Centrik-Lok clamps the shaft concentrically on a full circumference rather than wedging on one side, which keeps the shaft centred to the bearing bore and suits reversing drives. At 14000 RPM the 203 size carries the highest speed ceiling in the series.

Published ratings and mounting data

Bore: 5/8 in / 0.625 in / 15.875 mm
Size code: 203
Base to bore centreline height (A): 1-1/16 in / 26.97 mm, ±0.005 in
Bolt slot centres (B), minimum: 3-1/8 in / 79.40 mm
Bolt slot centres (B), maximum: 4-1/8 in / 104.8 mm
Overall length (C): 5 in / 127.0 mm
Mounting bolt size: 3/8 in / M10
Dynamic load rating: 1820 lb / 8100 N
Static load rating: 1110 lb / 4940 N
Approximate speed limit, Type N seals: 14000 RPM
Lubrication fitting: 1/4-28 UNF
Weight: 1.28 lb

Quantity and configuration

1 Pc. Complete housed unit: cast iron low-base pillow block housing with corrosion-resistant powder coat, the KMB45-58-PA wide inner ring insert and its Centrik-Lok concentric collar fitted. Relubricatable through the 1/4-28 UNF fitting. Lip seals standard. Alignable, non-expansion.

Fitting notes

The base seats on a flat rigid face, shimmed where uneven. The slots allow the block to be traversed to the shaft centre anywhere between 3-1/8 in and 4-1/8 in bolt centres before the 3/8 in base bolts are drawn down; the insert then settles into its aligned seat, and the Centrik-Lok collar is clamped onto the shaft last. Shaft seat is a commercial ground 0.625 in diameter.

Interchange guidance

The Dodge P2B-SC-010 matches this unit on mounting geometry: 1.06 in base to bore centreline and an overlapping slot range of 3-1/4 in to 4-1/16 in. It is a setscrew unit rather than Centrik-Lok, so it is a mounting interchange with a different locking method. The standard-backing Rexnord KC45-58 is the same bearing in a taller casting and the narrow-insert CL25-58 is the same style with a narrow inner ring, so both are related sizes rather than interchanges. The Centrik-Lok collar is a Rexnord patented design, so no other brand publishes a same-spec locking equivalent.