Bearing Inserts

UC inserts use dual setscrews at 120° to lock the wide inner ring to the shaft — bidirectional, the most common insert type. NA inserts use an eccentric collar: turning the inner ring locks the shaft via the elliptical collar mesh, then a setscrew prevents slipping. NA is self-tightening under unidirectional rotation and must not be used on reversing drives. UE inserts use a concentric (Accu-Grip®) collar: a hex screw squeezes the collar uniformly against a grooved inner ring, providing 360° contact. UE is bidirectional, generates no imbalance mass, prevents shaft marring, and is the correct choice for high-speed applications.

L3 designates a triple lip seal instead of the standard single rubber contact seal. The triple lip seal has three contact lips that provide greater contamination exclusion than the single seal. It is specified for dusty, wet, or heavily contaminated environments where the standard seal lifespan is insufficient. L3 inserts are dimensionally identical to standard inserts at the same designation and are directly interchangeable in the same housing.

Spherical O.D. inserts (UC, NA, UE, SA, UK, UD series) have a convex spherical outer surface that self-aligns in the housing bore, accommodating angular misalignment and allowing the housing to be installed on an out-of-alignment shaft axis. Cylindrical O.D. inserts (CUC, CSA, CSB, UER, SER series) have a plain cylindrical outer surface. They are used in pressed steel housings (SAPP, SBPP, SAPF, SBPF series) where the housing bore is machined to receive the cylindrical OD directly. Cylindrical O.D. inserts cannot self-align and must be installed in a correctly aligned housing.

UK inserts have a tapered inner bore instead of a parallel cylindrical bore. A separate adapter sleeve (ordered separately by sleeve designation) fits between the UK insert and the shaft, using the taper to clamp the insert to the shaft without touching the shaft surface directly. The sleeve distributes clamping force over its full length, providing true 360° shaft contact with no setscrew indentation or eccentric collar marking on the shaft surface. UK inserts are specified for applications where the shaft will be reused between bearing replacements, where shock loads can damage setscrew or eccentric collar retention, or where the shaft surface is rough-turned.

UD inserts have a non-extending (flush-back) inner ring — the inner ring does not protrude beyond the outer ring face on either side. This flush-back design allows the UD insert to be mounted in a standard housing where the inner ring protrusion of a UC insert would interfere with adjacent components or the machine frame. The bore tolerance of UD inserts is more precise than standard UC inserts, allowing press-fit shaft mounting in some applications.

Standard parts: quantity-based MOQ per model number. New-client samples: 1–5 pcs at sample price for first-time buyers. Multi-model orders: aggregate orders of USD 1,500 or more across models accepted. Retail (1–2 pcs): not accepted. Engineering drawings required before order confirmation for non-standard configurations.