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Sourcing note
A bearing cross reference chart looks like a simple tool. One column of numbers goes in, another column comes out, and the part you need appears on the right. On paper that is the whole job.
On the bench it rarely ends there. Two charts from two suppliers often list a different match for the same number, and neither chart knows what the bearing has to survive.
01What a Chart Can and Cannot Do
A chart is a lookup table. Someone at a distributor or a maker built it by comparing catalog data across brands, using bore, outside diameter, width, and ring type. You give it a number and it hands back the closest equivalent.
That is the full extent of what it does. It does not know your clearance class, whether the original part was sealed on both sides, or how far the housing bore has worn since the machine was built. Those details live in the drawing.
Most of what a maintenance team handles falls into one family, so the lookup is often easy. Deep groove ball bearings cover a large share of pumps, fans, conveyors, and small gearboxes, and their numbering stays fairly consistent across makers.
02Read the Number in Blocks, Not as a Whole
Metric ball bearing numbers follow the same rough pattern almost everywhere. Split a code into blocks before you open any chart and half the confusion goes away on its own.
The Series Block
The first two digits set the type and the size series. Numbers starting with 60 are a light series, 62 is a medium-light series, and 63 is heavier for the same bore. A 6304 ring is wider and thicker than a 6204 that fits the same shaft.
The Bore Block
The last two digits give the bore. From 04 upward, multiply by five and you have the bore in millimeters. A number ending in 04 fits a 20mm shaft, so a 6204 bearing and a 6304 share a journal and differ in outer size. A 6004 bearing takes the same 20mm shaft in a smaller envelope again, which is why the outside diameter has to be checked before a swap.
The Suffix Block
Everything after the digits describes how the part is closed, greased, and graded. ZZ is a pair of metal shields, 2RS is a pair of rubber seals, C3 is a looser internal clearance than the standard build. Read this block before you accept any match.
What the Chart Leaves Out
Most tables stop at boundary dimensions. Precision grade, cage material, and grease fill are usually absent, and any one of them can decide whether a replacement lasts a season or a month.
A plain walk through the whole code, suffix included, sits in our note on how to read a bearing code if you want the longer version.
03The Four Checks Before Any Swap
Before a cross reference number turns into a purchase order, four things need to agree. Three of them are dimensional. The fourth decides how the bearing behaves once it is warm.
| Check | What to confirm | Why it decides the outcome |
|---|---|---|
| Boundary dimensions | Bore, outside diameter, and width measured on the part, not copied from the label | A housing worn oversize changes the fit even when the numbers agree |
| Shoulder and fillet | Shoulder height on both rings and the corner radius of the shaft | A wider ring or a larger fillet can stop the part from seating |
| Internal clearance | C2, CN, C3, or C4 as marked, plus the fit and the running temperature | A tight fit or a hot housing eats clearance and the bearing runs preloaded |
| Sealing and lubrication | Shield or contact seal, and the grease the duty actually needs | A shielded part in a wet or dusty spot fails early and looks like a quality problem |
Four lines. If the supplier can answer all four from the drawing and the marked part, the substitute is worth a trial. If any line comes back as an estimate, keep looking.
The trial itself should be short and boring. Fit one unit in the position, run it through a normal shift, and check the housing temperature by hand before you shut down. A part that runs cool and quiet has passed the only test that matters.
04Where Two Charts Disagree
Two charts can disagree for reasons that have nothing to do with error. One may have been built on inch sizes converted to metric. Another may treat a thin-section series as interchangeable with a standard series because the boundary dimensions line up.
Neither chart is wrong on its own terms. They were answering slightly different questions, and neither was answering yours. That is why a chart is a starting point and never a release document.
There is a third case worth knowing about. Machine builders sometimes print their own house numbers on a drawing, and those numbers may not appear in any public chart at all. When that happens, the drawing and the marked part are the only reliable sources, and a distributor who claims otherwise is guessing.
05If All You Have Is the Old Bearing
Measure the part. Bore, outside diameter, width, and the seal type place a bearing in the right family quickly, even when the marking is worn past reading.
Then read whatever is left of the code. The series digits and the suffix usually survive on the ring face even when the middle of the number is gone, and the suffix is where most substitution mistakes begin.
If a machine runs several sizes, keep a short record per position. A 6205 bearing on a fan shaft and the same size on a pump shaft may need different clearance and different sealing, and the paperwork is what tells them apart two years later.
06When the Suffix Is the Whole Story
Two parts can share a code and still behave differently. The digits describe geometry. The suffix describes the build, and the build is what the application actually feels.
Ask what the original part was doing. A bearing in a washdown area with metal shields was the wrong choice from day one, and matching it exactly repeats the mistake. A bearing in a hot housing with standard clearance may have been running tight for years.
A habit worth keeping
When a number is offered as a match, ask for the suffix breakdown in writing. Two lines from the supplier settle most arguments before the part ships.
07Send the Number Instead of a Guess
Not every code can be placed from a catalog page. Mixed prefixes, retired series, and numbers from a machine builder’s own drawing all need a second look before anyone commits to stock.
Working from a number you cannot place
Send the marked code, a photo of the ring face, and the shaft and housing dimensions. An application engineer at Yuanhe will check it against the drawing and tell you what matches, what does not, and where the difference sits. Use the contact form or write to sales@yuanhecd.com.
08Questions Buyers Ask Before a Swap
Can a cross reference chart replace a drawing?
No. A chart maps published dimensions. It cannot confirm the fit in your housing, the clearance the duty needs, or the sealing the environment demands. Use it to narrow the field, then confirm against the drawing.
What if the chart lists two matches with different suffixes?
Treat them as two different parts. Compare bore, outside diameter, and width first, then clearance and sealing. The one that matches all four is the candidate. The one that matches three is a risk.
Is a heavier series always the safer substitution?
Not automatically. A 63 series ring is thicker and wider than a 62 of the same bore, and it may not clear the shoulder or the housing wall. Extra capacity you cannot fit is worth nothing.
How do I confirm a match before ordering volume?
Take a sample, measure it, and run it in the position. Watch temperature and noise through the first hours of running. A trial unit costs far less than a pallet of the wrong part.
Do inch and metric bearings cross over cleanly?
Rarely without a check. A converted inch size can land on a metric number that looks close but is not identical, and the difference often shows up in width or in the corner radius. Measure both parts before you treat them as the same.
09Keep a Record of What You Swapped
Every substitution is a small decision that someone will have to repeat in two years. Write down the old number, the new number, the date, and who approved it. Note the suffix difference in one line.
That record is what turns a chart into a system. When a 6304 bearing is approved as a replacement in one position, the next person should not have to rediscover why.
It also gives you a way to check a supplier later. If two shipments behave differently, the record shows whether the specification changed or the part did.
Next step
Send the number you are trying to match. A photo of the marking, the shaft size, and the housing bore are usually enough for a first answer.
Email sales@yuanhecd.com or use the contact form. We will reply with the dimensions we can confirm and the points we still need from you.
