McGillCL-25 15/16Two-Bolt Low Base Ball Bearing Pillow Block, 15/16 in Bore, Spring Locking Setscrews, Cast Iron

Product Description

What this part is

A complete housed ball bearing unit in the two-bolt pillow block style, from the MB 25 standard duty series with the low backing height casting. Bore is 15/16 in (23.813 mm), size code 205. The one-piece cast iron housing sits on a foot with elongated bolt slots. Locking is by spring locking — two concentric setscrews at 90° in the narrow inner ring.

Decoding the designation

C — pillow block with standard backing height
CL — pillow block with low backing height, the shorter base-to-shaft-centre casting
25 — narrow inner ring, standard duty, spring locking
35 — narrow inner ring, medium duty, spring locking, the next series up
25K / 35K — the Centrik-Lok concentric collar versions of the same series
15/16 — inch bore, 0.9375 in
Insert bearing number MB25-1516, spherical outer surface with lube groove and anti-rotation pin

Housing style

Two-bolt foot-mounted pillow block, low backing height, one-piece cast iron. The base bolt holes are elongated slots, so the unit takes up shaft-centre variation along the bolt axis at installation.

What these specs mean in practice

Low backing height puts the shaft centreline closer to the mounting surface than the standard C25 casting of the same bore, which is what suits it to shallow frames and clearance-limited positions. Spring locking uses two concentric setscrews at 90° rather than a collar, so the inner ring grips the shaft on two bearing surfaces and holds in either direction of rotation. The narrow inner ring gives a shorter bearing envelope than a wide-inner-ring unit of the same bore, at a lower load rating. The spherical outer surface of the insert takes up initial mounting misalignment; the anti-rotation pin keeps the insert from creeping in the housing bore.

Published ratings and mounting data

Bore: 15/16 in / 0.9375 in / 23.813 mm
Size code: 205
Dynamic load rating (C): 10810 N / 2430 lb
Static load rating (Co): 7830 N / 1760 lb
Approximate speed limit, Type N seals: 9600 RPM
Approximate speed limit, flingers only: 11400 RPM
Approximate speed limit, Type E / E1 seals: 6800 RPM
Operating temperature range: −40 to +225 °F

Quantity and configuration

1 Pc. Complete housed unit: cast iron low-base pillow block housing with the MB25-1516 insert bearing and its spring locking setscrews fitted. Relubricatable. Type N single-lip steel-clad contact seals with flingers.

Fitting notes

The base seats on a flat rigid face, shimmed where uneven. The elongated slots allow the block to be traversed to the shaft centre before the base bolts are drawn down; the spherical insert then settles into its aligned seat, and the setscrews are tightened against the shaft last. Shaft seat is a commercial ground 15/16 in diameter.

Interchange guidance

The CL25 line cross-references to low-base two-bolt ball bearing pillow blocks in other schemes: AMI UCLP205 series, Dodge P2B-SCB series, INA RAKY series, Link-Belt PL3-U216N series, SKF SYH TF series, Timken YAK series. Those use wide inner rings and setscrew or collar locking, so the mounting style matches while the insert construction differs. The standard-backing McGill C-25-15/16 is the same bearing in a taller casting, so it is a related size rather than an interchange. The Centrik-Lok CL25K-15/16 substitutes a concentric collar for the spring locking setscrews.