SNFASEA40-7CE13TDSuper Precision Angular Contact Spindle Bearing, 40 mm Bore — Outside Diameter, Width and Contact Angle To Be Confirmed Before Ordering

Product Description

What this part is

An SNFA super-precision angular contact ball bearing with a 40 mm bore, from the company’s spindle-bearing range. SNFA was a French specialist in high-speed spindle and ball-screw support bearings; the business was acquired by SKF, so SNFA designations are a common obsolescence trail into current SKF super-precision numbering.

Correcting the source data

This listing has an internal contradiction we have not been able to resolve from the data alone, and we would rather say so than publish a confident guess.

The recorded designation is SEA40. In SNFA’s naming, the series letters set the cross-section:

SEA is the extra-thin 718 series. On that reading, SEA40 is the 71808 envelope — roughly 40 x 52 x 7 mm.
VEX and HX are the heavier 70 series. On that reading, a 40 mm bore gives the 7008 envelope — 40 x 68 x 15 mm.

The dimensions recorded on this listing are 40 x 68 x 15 mm, which is the VEX40 / HX40 (7008) envelope — not an SEA40. The two cannot both be right.

We can corroborate the SEA convention from our own stock rather than from theory: we also hold an SNFA SEA110, and its dimensions are 110 x 140 x 16 mm, which is exactly the 71822 envelope. That confirms SEA maps to the 718 extra-thin series, and therefore that SEA40 should be a shallow 40 x 52 x 7 mm bearing, not a 40 x 68 x 15 mm one.

So either the part in hand is an SEA40 and the dimensions are wrong, or the dimensions are right and the part is a VEX40 or HX40 rather than an SEA40. We have published neither as fact. Bore, outside diameter and width are all left unstated pending measurement.

The contact angle is also unresolved

The recorded suffix is 7CE13. SNFA’s published forms are 7CE1 and 7CE3, which are different bearings — 7CE1 corresponds to a 15° contact angle and 7CE3 to 25°. “7CE13” appears to be the two forms run together at listing time. We are not guessing which one this is, because a 15° and a 25° bearing behave very differently in a spindle: the 15° runs faster and cooler, the 25° is markedly stiffer axially. The trailing TD is an SNFA arrangement suffix for which we found no published decode, so it is retained as a search term only.

Quantity is also unresolved

The listing title says “3 Pcs” while our stock record shows a quantity of 20. Those are not reconcilable from the data, and SNFA spindle bearings are routinely sold in matched sets, so the 20 could be individual bearings or sets. We have not changed the inventory figure and we are publishing no quantity claim.

What to do before ordering

Please contact us. We will measure the outside diameter and width, read the ring etching for the exact contact-angle suffix and arrangement, and give you a confirmed physical count. All three questions are answerable in a few minutes with the parts in hand, and we would rather do that than have you fit the wrong bearing to a spindle.

What we can say with confidence

Whichever envelope it turns out to be, this is a super-precision angular contact spindle bearing, not a general-purpose one. SNFA’s spindle range is built for high-speed machine-tool and ball-screw support duty, held to close running-accuracy limits, and intended to be mounted in matched, preloaded arrangements. Universally ground spindle bearings of this kind must never have their faces shimmed, lapped or reground — the preload is built into the ring faces — and they must be fitted observing the thrust-direction marking on the outer ring.

Published ratings and mounting data

Load ratings and limiting speeds are deliberately blank. With the envelope and the contact angle both unresolved, any figure we quoted would be a guess. Once the measurement is done we can identify the exact SNFA or SKF designation and point you at the manufacturer’s published data.

Interchange guidance

SNFA super-precision numbering crosses into SKF’s range following the acquisition. If the part proves to be a 7008 envelope, the ISO base number is 7008; if it proves to be a 71808, the base number is 71808. Those are very different bearings despite the shared 40 mm bore, which is precisely why we are not guessing.