NTNPrecision Angular Contact Ball Bearing – 50 mm Bore, 90 mm OD, 20 mm Width, 15° Contact Angle, P5 Class, Phenolic Cage

Product Description

What this part is

An NTN 7210CT1GP5 precision single-row angular contact ball bearing, 50 mm bore, 90 mm outside diameter, 20 mm width. Open on both faces, straight bore, machined phenolic cage, P5 tolerance class, universally ground so that bearings of the same designation can be matched into sets.

Decoding the designation

72 is the ISO dimension series and 10 the bore code, giving a 50 mm bore. In NTN’s scheme C is a 15° contact angle. T1 is the machined phenolic cage. G is the universal-grinding and preload block, marking the bearing as ground for matched-set assembly rather than as a stand-alone single. P5 is the tolerance class, equivalent to ABEC 5.

What these specs mean in practice

A 15° contact angle sits at the high-speed, low-thrust end of the angular contact range. Compared with a 25° or 40° bearing in the same 50x90x20 mm envelope it reaches a higher limiting speed and generates less heat, while carrying less axial load. P5 tightens bore, outside diameter, width and both radial and axial runout well beyond normal class, which is what makes the bearing suitable for a spindle or a positioning axis where shaft runout is part of the machine’s accuracy budget. Single-row angular contact bearings take thrust in one direction only.

Cage material and temperature

The T1 phenolic cage is machined from cotton-fabric-reinforced phenolic laminate. It is light, quiet and self-lubricating, and it suits high-speed running with oil, oil-mist or oil-air lubrication. Phenolic has a lower continuous temperature ceiling than a machined brass cage, and the brass execution of the same envelope is designated with an M or MB cage code.

Quantity and configuration

1 Pc. Single bearing, supplied loose. The G universal grinding means bearings of this same full designation stack into back-to-back, face-to-face or tandem sets with the preload set by the grinding rather than by ground spacers.

Mounting data

Bore form: straight, for an interference-fit shaft seat. Outer ring location: bored housing against a square shoulder. Thrust face: marked by the high shoulder on each ring. Back-to-back (DB) arrangement: outer-ring high shoulders face outward, giving maximum stiffness and moment capacity. Face-to-face (DF) arrangement: the more misalignment-tolerant of the two.

Interchange guidance

NSK 7210CTYNP5 matches the 50x90x20 mm size, 15° angle and P5 class. FAG B7210-C-TPA-P5 also has a 15° angle but a polyamide cage. Cage material and the preload or universal-grinding code must match across every bearing in a set. A 7210 in an A, A5, B or E execution carries a different contact angle, and a 7210 at P6 or normal class is a different tolerance grade, so both are related sizes rather than direct matches.