MBCL-25-1-5/82-Bolt Low-Backing Pillow Block Ball Bearing Unit 1-5/8″ Bore, Spring Locking, Self-Aligning, Cast Iron

Product Description

What this part is

An MB-series CL-25-1-5/8 mounted ball bearing unit — a two-bolt cast iron pillow block in the low-backing housing, for a 1-5/8 inch shaft. It bolts to a horizontal surface below the shaft and carries a narrow inner ring, standard-duty ball insert with a spherical outer race, so the unit takes up angular error at installation.

Correcting the source data

Earlier copy described this as a flange mount bearing. It is a pillow block. In MB-series numbering C is a pillow block with standard backing and CL is a pillow block with low backing — the flange codes in the same scheme are FC2 (two-bolt), FC4 (four-bolt) and MFB (three-bolt bracket). A pillow block and a flange do not share a footprint or a mounting orientation, so this will not go where a flange unit was.

Decoding the designation

CL = pillow block, low backing dimension. 25 = narrow inner ring, standard duty, spring locking. 1-5/8 = shaft diameter in inches. The listing also carries the interchange numbers NPL-26 and Dodge P2B-SCB-110, plus MB part number 123858 — all searchable references for the same 1-5/8 inch two-bolt pillow block position.

Two things worth checking before ordering

Low backing means the shaft centre sits closer to the mounting surface than on the standard-backing C version. Swap one for the other and your shaft line moves, so measure the base-to-shaft centre height on the block you are replacing.

Spring locking is not a setscrew or an eccentric collar. In the MB 25 and 35 series the insert is retained by a spring locking arrangement rather than screws driven into the shaft, so there is nothing to torque into the shaft surface and nothing to indent it — but it is also not the part to substitute with a setscrew insert without checking the housing seat and inner ring form.

Published specifications

Housing style: two-bolt pillow block, cast iron, low backingBore / shaft size: 1-5/8 in (41.28 mm)Insert: narrow inner ring ball bearing, standard duty, spherical outer raceLocking method: spring lockingSelf-aligning: yesRolling elements: ball · number of rows: 1Design units: inch

Quantity and configuration

Sold as 1 pc — one complete unit, cast iron housing with the insert fitted. Mounting bolts are not included.

Fitting notes

Bolt to a clean, flat, rigid surface and shim rather than pulling the base onto a high spot; a twisted base loads the spherical seat and removes the misalignment allowance. Fit the unit to the shaft, secure the insert, then rotate the shaft by hand and confirm the insert still swivels in its seat before final tightening.

Interchange guidance

Cross-referenced to NPL-26 and Dodge P2B-SCB-110 in this bore. Other two-bolt pillow blocks at 1-5/8 in come from SealMaster (MP/NP), Link-Belt (P3U/PB), Dodge (P2B) and Browning (VF), but bolt centre-to-centre and base-to-shaft centre height vary by maker — measure both against your frame before treating any as a drop-in. Related, not interchangeable: the standard-backing C-25-1-5/8, and a 35-series insert in the same housing, which is medium duty rather than standard.