Fafnir2MM220WISULAngular Contact Ball Bearing – 100 mm ID, 180 mm OD, 34 mm Width, 15° Contact Angle, Phenolic Cage, Light Preload, ABEC 7/9 P4S

Product Description

What this part is

Fafnir 2MM220WICRSUL is a super-precision angular contact ball bearing, universally ground as a single for duplex service. Bore Diameter: 100 mm. Outside Diameter: 180 mm. Overall Width: 34 mm. Contact Angle: 15°. Bore Type: Straight. Closure Type: Open. Rolling Elements: Ball. Number Of Rows: 1. Cage Material: Phenolic. Bearing Material: Bearing steel. The envelope is the ISO 7220 size.

Decoding the designation

2MM — Timken Fafnir super-precision at a 15° contact angle. The 2 prefix carries the angle; MM is the P4S precision grade, which holds ABEC 9 / ISO P2 running accuracy on an ABEC 7 / ISO P4 body.

220 — the 200WI dimension series at bore code 20, which is ISO 72-series size 7220 at 100 x 180 x 34 mm. The 200 series is the heavier section of the two spindle ranges, trading speed for capacity and stiffness.

WI — Timken’s standard angular contact construction: full shoulders on both sides of the inner ring and a low shoulder on the outer ring.

CR — phenolic composition cage, Timken’s standard cage for super-precision spindle bearings.

SUL — single, universally ground, light preload. Faces are ground flush so two or more bearings stack back to back, face to face or in tandem and reach light preload without shims.

What these specs mean in practice

Dynamic Load Rating: 165,200 N. Static Load Rating: 126,800 N. Both are Timken C1 and C0 values for a single bearing.

Limiting Speed: 8,000 rpm grease; 16,000 rpm oil. The oil figure is double the grease figure because oil carries heat out of the contact that grease cannot.

Contact Angle: 15°. A shallow angle favours speed and radial stiffness over axial capacity, which is the trade a machine tool spindle wants.

Preload: Light. Light preload keeps running temperature and power draw down while still removing play from the spindle, and it is the usual choice where speed matters more than absolute stiffness.

Precision Class: ABEC 7/9 / P4S. Super-precision grinding holds bore, outside diameter and raceway running accuracy far tighter than a standard-class bearing, which is what keeps spindle runout and running vibration low at speed.

Mounting data

Bore Diameter: 100 mm. Outside Diameter: 180 mm. Overall Width: 34 mm. Shaft Backing Shoulder Diameter: 114.4 mm (4.510 in). Housing Backing Shoulder Diameter: 166 mm (6.540 in). Maximum housing fillet radius that the bearing corners will clear: 2.1 mm (0.079 in). Item Weight: 3.209 kg (7.07 lb). Bore Type: Straight, for an interference fit on a ground spindle journal.

Quantity and configuration

Unit Quantity: 1 Pc. Mounting Arrangement: Universally ground single (SU). Series: 2MM200WI. Base Number: 2MM220WI. GTIN: 087796015654. Harmonization Code: 8482.10.50.

Interchange guidance

The ISO 7220 envelope at 15° and P4-class precision is made by every major super-precision manufacturer, and the equivalents are listed in the cross-reference fields. Match preload as well as angle: 2MM220WI-SUL is ground to light preload and 2MM220WI-SUM to medium, and the two carry different Timken UPCs while sharing identical ratings and dimensions.