NSK7208A5TYSULSuper-Precision Angular Contact Ball Bearing – 40 mm ID, 80 mm OD, 18 mm Width, Open, 25° Contact Angle, Light Preload, Single Universal

Product Description

What this part is

NSK 7208A5TYSUL super-precision single-row angular contact ball bearing. Bore: 40 mm. Outside Diameter: 80 mm. Overall Width: 18 mm. Number Of Rows: 1. Rolling Elements: Ball. Bore Type: Straight. Closure Type: Open. Bearing Material: carbon chrome bearing steel to SAE 52100, through hardened and heat treated. Series: 7200, ISO dimension series 02. Item Weight: 0.366 kg (0.81 lb).

Decoding the designation

Contact Angle: 25°, given by the A5. Cage Type: ball-guided, given by the TY. Preload: light, given by the L. Mounting Arrangement: single universal, given by the SU. Searchable forms of the number: 7208A5TYSUL, 7208-A5-TY-SUL, 7208 A5 TY SUL, 7208A5.

Load ratings and speed

Dynamic Load Rating: 34.5 kN (7,756 lbf). Static Load Rating: 24.1 kN (5,418 lbf). Limiting Speed: 26,800 rev/min on oil/air lubrication and 16,500 rev/min on grease. Effective load centre: 23.0 mm. Lubricant: grease or oil.

What these specs mean in practice

A 25° contact angle carries more thrust and gives more axial stiffness than the 15° execution of the same size, and it trades speed for it: 26,800 rev/min on oil/air against 30,600 for the 15° part. Light preload develops 290 N of axial preload and 136 N/µm of axial stiffness in a back-to-back pair, holding true rolling contact at speed with less heat than a medium or heavy setting. Universal grinding means the inner and outer rings are the same width and flush ground, so any two of these bearings clamp back-to-back or face-to-face at the rated preload with no custom spacer, and share load equally in tandem. A ball-guided cage is centred by the rolling elements themselves rather than by a ring land, which keeps cage drag low across a wide speed range.

Mounting data

Shaft abutment diameter d1 min: 47 mm. Housing abutment diameter D1 max: 73 mm. Housing abutment D2 max: 75 mm. Bearing fillet radius r min: 1.1 mm. Fillet radius r1 min: 0.6 mm. Internal free volume: 15.5 cm³. Pitch circle diameter for lubrication jets: 55.5 mm.

Quantity and configuration

Unit Quantity: 1 Pc. Internal Clearance: N/A. The bearing is preload-set at manufacture rather than clearance-set, so no radial clearance class applies.

Interchange guidance

Carton designations carried on this part: 3MM208 WI CR UL and B7208E. The Fafnir 3MM prefix and the RHP B-series E code both give the same 25° angle. Same-envelope 25° super-precision executions in other schemes: SKF 7208 ACD/P4A, FAG B7208-E-T-P4S-UL and RHP 7208ETSULP4. A 7208C in this 40 x 80 x 18 mm envelope carries a 15° contact angle, which makes it a related size rather than a substitution.