SNFA71822CDHCP4Super Precision Angular Contact Spindle Bearing 110x140x16 mm, Extra Thin Section, 15° Contact Angle, P4 Precision Class

Product Description

What this part is

An SNFA super-precision angular contact ball bearing in the 71822 envelope — 110 mm bore, 140 mm outside diameter, 16 mm width. This is an extra-thin-section spindle bearing: only 15 mm of radial section between bore and outside diameter for a 110 mm shaft.

SNFA was a French specialist in high-speed spindle and ball-screw support bearings, acquired by SKF, so SNFA designations are a common obsolescence trail into current SKF super-precision numbering.

Decoding the designation

SEA — SNFA’s extra-thin 718 series. The recorded dimensions, 110 x 140 x 16 mm, are exactly the 71822 envelope, so designation and dimensions agree and this part’s identity is internally consistent.
110 — the bore in millimetres. Note that SNFA numbers this series by actual bore size, not by ISO bore code.
71822C — the ISO-format equivalent designation. In the C = 15° convention this indicates a 15° contact angle.
P4 — ISO precision class 4, equivalent to ABEC 7.

What we have not decoded

The cross-reference recorded against this item, 71822CD.HCP4, is written in a Schaeffler-style format rather than SNFA’s own. In that format HC would ordinarily indicate hybrid ceramic balls, and D a duplex arrangement — but we could not confirm either against an SNFA or SKF source for this part, and ceramic balls are a significant and price-relevant specification to assert without evidence. We have therefore not published a ball material or an arrangement. Both are easy to settle physically: ceramic balls are visibly light grey rather than steel-bright. Contact us and we will look before you order.

What these specs mean in practice

Extra-thin-section bearings exist to solve a packaging problem: getting a large shaft, spindle nose or rotary table through a bearing without a correspondingly large housing. The cost is capacity and rigidity — a 16 mm-wide bearing on a 110 mm bore simply cannot carry what a 70-series bearing of the same bore would — and a heightened sensitivity to housing and shaft roundness. A thin ring conforms to whatever it is clamped into, so an out-of-round housing bore transfers straight into the raceway and shows up as runout and noise. Machine the seats accordingly.

A 15° contact angle is the high-speed, low-heat choice: it runs faster and cooler than a 25° bearing but gives away axial stiffness and thrust capacity.

Published ratings and mounting data

Load ratings and limiting speeds are deliberately blank. No manufacturer-published figure for this exact SNFA designation was retrievable, and we will not substitute figures for a general-purpose 71822 or for a neighbouring SNFA variant — different class and, potentially, different ball material. Contact SKF with the full SNFA designation if a certified rating is required.

Quantity and configuration

One bearing. Note that spindle bearings of this type are normally used in matched, preloaded arrangements; a single will function but carries no preload on its own.

Fitting notes

Observe the thrust-direction marking on the outer ring — an angular contact bearing fitted backwards loads the unsupported shoulder and fails quickly. Never shim, lap or regrind the ring faces on a preload-ground spindle bearing. Because the section is so thin, support the ring being pressed evenly around its full circumference and never drive force through the balls; a thin ring is easy to distort.

Interchange guidance

ISO base number 71822. SNFA numbering crosses into SKF’s super-precision range. A commercial-grade 71822 shares the envelope but is several tolerance classes coarser and is not a like-for-like substitute. If ball material matters to your application, confirm it — see above. We also hold an SNFA SEA40 in the same family; ask if you are matching a set.