Bearing cross reference by part number, from a plant's worn-parts list to a draft quote.

The list comes as an email, a spreadsheet, a scanned page from a planner's notebook or a photo of a shelf tag. One line gives a maker's number with a suffix, the next an old number from a line you never stocked, and the next a bore, outside diameter and width in a mechanic's handwriting. Somebody works out the basic bearing, reads each suffix, looks up what you stock and decides what to offer.

For the test, AI reads copies of those lists and drafts each quote line: the number as written, the basic size, bore, outside diameter and width, the seal, cage, clearance and precision codes it found, and candidate interchanges from your own files with the reason for each. Where the number is ambiguous or a suffix changes the fit, the line says so and goes to a person.

The basic number gives an envelope, not a bearing. From bore code 04 upward, the last two digits times five give the bore in millimeters, and 00, 01, 02 and 03 stand for 10, 12, 15 and 17. ISO 15 sets preferred boundary dimensions for radial bearings, which is why a size can line up across makers. It also means a caliper reading of 25 by 52 by 15 fits a 6205 deep groove ball bearing, a 7205 angular contact bearing and an NU205 cylindrical roller bearing. The letters decide the rest: an NU lets the rings shift along the shaft, an NJ takes limited axial force one way, and on one maker's list an A, B or C after an angular contact number means 30, 40 or 15 degrees. A handwritten line with three dimensions gets candidates of each kind and a question about what came off the shaft.

Some numbers come in halves, and some in two spellings. A tapered roller bearing's cone and cup separate, and a list may name only the half that wore out. On one maker's inch list a 1.75-inch cone in the 355 series mates with cups numbered 352 and 354A, and those two cups have different outside diameters, about 3.548 and 3.347 inches. ABMA 19.2 is the inch-design standard, while ISO 355 gives metric tapered bearings boundary dimensions and a series designation of their own. Inch insert bearings split the other way: a 1-3/16-inch bore is a UC206-19 on one list, counted in sixteenths, and a UC206-103 on another, one inch and three sixteenths. A plain UC206 is a 30-millimeter bore, and 1-3/16 inches is 30.16, close enough that a caliper won't settle it. The draft keeps inch and metric candidates apart and asks.

On spherical roller bearings the suffix decides how it mounts. On one maker's list K means a 1:12 tapered bore, K30 a 1:30 taper, and W33 an annular groove with three lubrication holes in the outer ring. Another maker's code for that lubrication feature is E4. Cage codes travel worse. One list writes M for a machined brass cage; another writes MA for a machined brass cage centered on the outer ring and J for a stamped steel cage centered on the inner ring. The draft shows each spelling as the customer wrote it beside the candidate, and a line where the cage or bore code was dropped comes back marked.

Clearance and precision are separate scales, and they run opposite ways. ISO 5753-1 gives radial internal clearance values for radial bearings and sends insert bearings to a different standard, ISO 9628. On one maker's list C2 is less than Normal, C4 more than C3 and C5 more than C4, and Normal clearance is left off entirely. Precision runs on ABEC 1, 3, 5, 7 and 9, where a higher number is tighter, beside ISO Normal, 6, 5, 4 and 2, where a lower number is tighter, and Normal is left off the number too. Inch tapered bearings use another set again: Class 4, 2, 3, 0 and 00. So P6 on one line and ABEC 3 on the next may ask for the same tolerance class, and a missing code may mean Normal or may mean nobody copied it. The draft never assumes which.

A customer may tell you which makers it will take, and your reviewer checks all of it. The City of Winnipeg's 2012 bid form for bearings names acceptable makers line by line: nine on the first five lines, including 32310J2/Q and 32022 XU, four on the next six, two on the next five and one on the last. The draft keeps a list like that on the line and proposes nothing from outside it. Your reviewer, usually the person others call about an odd number, checks that the basic size was read right, that every suffix survived or was flagged, that a missing half or a missing code became a question, and that any number that could mean two things went to a person.

When your reviewer says yes against the success criteria, the same job runs on incoming lists for about 30 days.

A qualified person checks every interchange and approves each quote before it posts anywhere or reaches a customer. Anything the draft marked stays marked until someone settles it.

The live month carries a fixed price you see before signing, and the next job is priced on its own.