Barden126HDL-1/2PRSuper-Precision Angular Contact Ball Bearing – 130 mm ID, 200 mm OD, 33 mm Width, 15° Contact Angle, Light Preload, P4S, Universally Ground

Product Description

What this part is

Barden 126HDL super-precision angular contact ball bearing. Bore: 130 mm. Outside diameter: 200 mm. Width: 33 mm. Contact angle: 15°. Preload: light. ISO equivalent section: 7026. Fafnir carton designation: 2MM9126WIDUL. Country of origin: United States.

Decoding the designation

Barden series 126 corresponds to the ISO 7026 section, 130 x 200 x 33 mm. HD: matched duplex, ground for universal mounting. L: light preload grade. The carton also carries the Fafnir designation 2MM9126WIDUL — 2MM: 15° contact angle; 9126: the ISO 7026 section; WI: angular contact with a low-shoulder outer ring; DUL: duplex, light preload. Precision Class: P4S, ABEC 7 with ABEC 9 tolerances on selected features. 1/2PR: one bearing.

What these specs mean in practice

A 15° contact angle is the high-speed end of the angular contact range: it favours speed and radial stiffness over axial capacity, which is why it is the standard choice for grinding and milling spindles. Light preload keeps running friction and heat generation low while still removing all internal play, so the shaft holds position without the temperature rise a medium or heavy preload brings. P4S holds radial and axial runout to a few microns, giving low running vibration and close, repeatable shaft location. The low-shoulder outer ring is what allows the ball complement to sit at the 15° angle and lets the bearing be assembled at high precision.

Quantity and configuration

One piece. This is a single bearing out of a factory matched duplex pair, ground for universal mounting: two bearings of this designation can be set back-to-back, face-to-face or in tandem, and the light preload is achieved when a pair is clamped. A single bearing suits a spindle position that takes one bearing, or completes an existing pair of the same designation and preload grade.

Fitting notes

Universally ground bearings are mounted with the marked faces oriented per the arrangement chosen. Shaft and housing fits are held light on a super-precision bearing, since an interference fit changes the preload the manufacturer ground in. Thrust is carried toward the high shoulder of the outer ring. Clean assembly and a light spindle-grade oil or grease charge suit the P4S class.

Interchange guidance

Direct equivalents on the same designation: Fafnir 2MM9126WIDUL and the ISO 7026 15° super-precision section. Barden 126HDM and 126HDH are related sizes at medium and heavy preload — same envelope, different preload grade. A 25° bearing on this envelope, such as a 3MM9126WI, is also a related size. Searchable forms: 126HDL, 126-HDL, 126 HDL, 126HDL-1/2PR, 126HDL 1/2 PR, 2MM9126WIDUL, 2MM9126WI DUL, 7026.