I'm replacing the the drive spindle bearings and lower spindle bearings in my Central Machinery T-5980 mill/drill/lathe and am confused concerning the bearing numbers. It lists numbers as 205, 206, and 207. When I search these bearings, there are usually 2 or 3 digits preceding these numbers. Are these workable as long as the "205" etc. are included in these numbers? Thanks.
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Bearing replacement
- Thread starter supersix
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Those are good bearing numbers, just not necessarily complete. They are missing additional characters which show the variations, and manufacturers change the numbers, the prefixes, and the suffixes to try to keep you a customer. The Chinese just put the base numbers on them, so that number does not tell the whole story.
You will find stuff like:
205 typically an open ball bearing, no shields or seals
205ZZ double shielded Z would be single side shielded, though not dirt proof
205SS double sealed with rubber seals, keeps grit out
6205 variations (and thousands more)
bottom line, it is likely a 200 series bearing, 25mm bore, 52mm OD, 15mm thick. Confirm that...
A local bearing house will be able to help if you bring in a sample and tell them it is for a metal working machine. I recommend you do NOT buy the really cheap bearings from China (regardless of cost.) Get good American or European bearings, and watch out for counterfeits, which are everywhere. Use a provider who can be trusted. Unless there is a specific good reason not to, I would use double sealed bearings every time unless there is a specific reason for doing otherwise. HF only wants it to run during the short warranty period, you want it to live forever so you don't have to tear it down again, and run smoothly and quietly. Saving a couple dollars and having further problems, even damaging machine components, is not a smart repair.
Bottom line, those bearings are common and cheap, and easy to find. Get some decent ones. Sources like Fastenal, Grainger, and others usually have decent quality stuff. The best bet is to take a sample with you, and explain the application. Hope that helps.
You will find stuff like:
205 typically an open ball bearing, no shields or seals
205ZZ double shielded Z would be single side shielded, though not dirt proof
205SS double sealed with rubber seals, keeps grit out
6205 variations (and thousands more)
bottom line, it is likely a 200 series bearing, 25mm bore, 52mm OD, 15mm thick. Confirm that...
A local bearing house will be able to help if you bring in a sample and tell them it is for a metal working machine. I recommend you do NOT buy the really cheap bearings from China (regardless of cost.) Get good American or European bearings, and watch out for counterfeits, which are everywhere. Use a provider who can be trusted. Unless there is a specific good reason not to, I would use double sealed bearings every time unless there is a specific reason for doing otherwise. HF only wants it to run during the short warranty period, you want it to live forever so you don't have to tear it down again, and run smoothly and quietly. Saving a couple dollars and having further problems, even damaging machine components, is not a smart repair.
Bottom line, those bearings are common and cheap, and easy to find. Get some decent ones. Sources like Fastenal, Grainger, and others usually have decent quality stuff. The best bet is to take a sample with you, and explain the application. Hope that helps.
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Those appear to be standard metric bearing sizes- the other digits/letters should indicate presence/absence of seals, type of seals/shields
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Other descriptive numbers/characters will indicate the angular contact type of bearing very likely to be used on a machine spindle, especially the lower bearings; as was suggested, take the old bearings with you to the bearing house, just the bearing numbers that you quoted, do not mean much in the larger scheme of things.
Look for numbers on the bearings themselves, the harbor freight parts diagrams are about useless for bearing replacement. They want you to order them through them by their part #.
If no #'s on the bearings either measure them or take them with you to a bearing shop.
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RobertB is quite correct- the numbers in the parts list are only reference numbers for ordering from the factory, the actual bearing numbers are the ones printed on the bearings themselves
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With bearing replacement the tolerance matters. I changed out the tapered roller bearings on my Wabeco D6000 lathe and it was interesting to me at the time the actual number on the bearing also was for a car wheel bearing but the tolerance was P5 for precision. There was a big difference in price for the precision bearings but being for the lathe spindle it was necessary.
There is an inverse relationship with durability and precision. So a high precision bearing in a car wheel bearing having thousands of pounds on it would not hold up but same high precision bearing on a machine tool would.
When getting bearings be sure the person you speak to knows what it is for. The larger bearing places have people that will talk to you on the phone to order the right things.
There is an inverse relationship with durability and precision. So a high precision bearing in a car wheel bearing having thousands of pounds on it would not hold up but same high precision bearing on a machine tool would.
When getting bearings be sure the person you speak to knows what it is for. The larger bearing places have people that will talk to you on the phone to order the right things.
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I never heard that before, Cadillac, and I bought and sold all sorts and types of bearings commercially for 35+ years. Could you elaborate, please?
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When I was looking into the bearing issue a few years back I did a lot of web surfing about it. There is a lot of skateboard information with people wanting better bearings because that is something the user could change out easily on their own.
The point was made that you could use the highest precision bearings but they never would hold up for long so it was better not to use the very highest precision in that situation. I don’t recall the specific ABEC ratings they were comparing.
That is where I heard it and it made sense.
It is true there is no difference in durability based on precision? Nice to know.
I wonder if extreme precision bearings were used for car wheel bearing sets it would lead to better coasting and better miles per gallon.
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I think the issue with skateboard bearings is that they are not properly sealed, and run in a dirty environment, ruining the balls and races fairly quickly. Trash would attack all bearings equally, indeed. I took your post to say that more accurate bearings do not hold up to usage as well as less accurate bearings, and thought that there might be some truth to that if they are precision ground hardened balls instead instead of ones segregated by bounce testing, which is used in many bearings to check the heat treatment and also to separate the round balls from the not so round balls. That 'might' perhaps make a difference in longevity due to a harder and smoother 'skin' on the not ground bearing rolling surfaces, with all other factors being the same. Grinding the balls leaves the surfaces pitted on a microscopic level. Maybe...