RHP7021ETSULP4Super Precision Angular Contact Ball Bearing – Straight Bore, 105 mm ID, 160 mm OD, 26 mm Width, Open, 25° Contact Angle, Single Universal Light Preload, ABEC 7

Product Description

What this part is

RHP 7021ETSULP4 is a super precision single-row angular contact ball bearing, universally ground for matching, supplied as one bearing. Bore: 105 mm. Outside diameter: 160 mm. Width: 26 mm. Series: 7000, ISO dimension series 10. Contact Angle: 25°. Precision Class: ISO Class 4, equal to RHP P4, BS292 EP7 and ABEC 7. Searchable forms of the designation include 7021ETSULP4, 7021-E-T-SUL-P4, 7021 E T SUL P4, 7021A5, 7021ACD and B7021X3TAULEP7.

Decoding the designation

Type: single-row angular contact ball bearing. Dimension Series: 10. Bore Code: 21, giving a 105 mm bore. Contact Angle: 25°. Cage: T, a machined laminated phenolic cage guided by the outer ring. Grouping: SU, single universally ground. Preload: L, light. Precision Grade: P4.

What these specs mean in practice

A 25° contact angle carries more thrust and less speed than a 15°, which suits spindles working against heavy axial load. Dynamic Load Rating: 83.5 kN. Static Load Rating: 85.0 kN. Paired at light preload it sets 980 N of axial preload and delivers 317 N/µm of axial stiffness. P4 accuracy holds inner-ring radial runout to 5 µm and outer-ring radial runout to 7.5 µm, which lowers runout and vibration in a spindle. The laminated phenolic cage runs to 120 °C and is quiet at speed. Rings and balls are SAE 52100 chrome bearing steel, through hardened and heat treated for dimensional stability.

Speed and lubrication

Limiting speed as a single bearing under light external load: 11,100 rpm with oil/air lubrication and 7,200 rpm with grease. As a back-to-back light-preload pair those become 8,880 rpm and 5,760 rpm. Mounted face-to-face the pair figures halve again. Grease fill for a low or medium speed spindle is 30% of the 68.0 cm³ internal volume, 20% above 60% of maximum speed, and 10 to 15% above 80%. Lubrication jet pitch circle diameter: 125.1 mm.

Quantity and configuration

Unit Quantity: 1 Pc, one single universally ground bearing. Universal face control means it pairs with another SUL bearing of the same designation back-to-back, face-to-face or in tandem at the light preload value, with no ground spacers required. The high point of radial runout is marked by a burnished spot on the inner ring face and a V line on the outer diameter; the V also shows the direction of the contact angle.

Fitting notes

Effective load centre a: 43.9 mm. Abutment diameters: shaft shoulder d1 115 mm minimum, housing shoulder D1 150 mm maximum, seal counterbore D2 154 mm maximum. Fillet radii: r 2.5 mm, r1 1.0 mm. Mass: 1.574 kg. Recommended shaft fit at 105 mm is a mean interference of 3 µm; recommended housing fit at 160 mm for a locating bearing is a mean clearance of 7 µm.

Interchange guidance

Closest matches at the same envelope, 25° angle and light preload: SKF 7021 ACDGA/P4, FAG B7021-E-T-P4S-UL, Fafnir 3MM9121WI-SUL and RHP B-series B7021X3TAULEP7. NSK 7021A5TYNSULP4 has a polyamide cage. Fafnir 3MM9122WI is a 7022 at 110 x 170 x 28 mm. NSK 7021A is a 30° bearing. RHP 7021C is the 15° bearing in the same envelope.