NHBBME-1209DLMatched Pair Super-Precision Angular Contact Ball Bearings, 45x85x19 mm Each, 15° Contact Angle, Light Preload, P4 / ABEC 7

Product Description

What this part is

A duplex matched pair of NHBB super-precision angular contact ball bearings, 45 mm bore by 85 mm outside diameter by 19 mm wide per bearing — the 72-series envelope corresponding to metric 7209. New Hampshire Ball Bearings builds to aerospace and instrument standards, and its metric precision numbers carry the ME prefix.

Decoding the designation

ME — NHBB metric precision angular contact series

1209 — the 7209 envelope: 45 mm bore, 85 mm outside diameter, 19 mm wide

DL — duplex, light preload; the carton’s alternate designation 7209-C-TPA-P4-DUL spells out the same thing as DUL

C (on the alternate number) — 15° contact angle

P4 (on the alternate number) — ISO tolerance class 4, equivalent to ABEC 7

Correcting the source data

The record asserted manufacture in the United States. NHBB is an American manufacturer, but no origin marking is documented for the item in hand, so no origin is claimed on the page. The previous copy also described this as a general-purpose ball bearing suitable for hobbyist projects, which badly undersells a P4 duplex-matched spindle set; that framing has gone, along with the shipping promises and upgrade-your-equipment copy.

What these specs mean in practice

15° is the high-speed, low-friction contact angle: strong radially, cool-running, modest in axial capacity. Light preload keeps heat down and the speed ceiling up, which is why DL and DUL sets are the default in grinding heads and high-rpm spindles rather than in heavy roughing arrangements. Because the pair was ground as a set to reach that preload, mounting one of these against an arbitrary 7209 leaves you with an arrangement whose preload nobody can predict.

Published ratings and mounting data

No manufacturer-published basic dynamic or static load rating could be verified for this designation, so none is stated rather than borrowed from a catalogue 7209. Boundary dimensions 45 x 85 x 19 mm per bearing are the ISO 72-series values and are confirmed; a mounted pair stacks to 38 mm.

Quantity and configuration

One matched pair, two bearings. Stock is recorded as 1, which on this record means one pair. Do not split the pair.

Interchange guidance

Metric equivalent: 7209-C-P4-DUL. Same-envelope 15° light-preload equivalents include NSK 7209CTYNDULP4, SKF 7209 CDGA/P4A, FAG B7209-C-T-P4S-DUL and Fafnir/Timken 2MM209WI DUL. A 25° bearing in this envelope (NSK A5, SKF AC, FAG E, Fafnir 3MM) will fit the housing and change the spindle’s stiffness and speed limit, so it is not a substitute.