Re: Replacement blade guide bearings

Hi Terry
I presume from the header you need new guide bearings.
All Taiwanese and Chinese manufactured saws have metric bearing sizes even if they have UNC threads on their (metric headed) bolts. Some early American made saws had special bearings with a flange on the outer race instead of a rear guide-roller and some had cam-follower bearings, these may have been inch sizes.

The following metric size deep groove ball bearings have been used:

Inside Diameter (mm)	Outside Diameter (mm)	Width (mm)	?滨苍迟’濒.[1] Bearing code	Preferred Radial Internal Clearance grade	Comment
5	16	5	625	MC3	as rear guide-roller
8	22	7	608	MC3	as rear guide-roller
9	26	8	629	MC3	as rear & side guide-rollers
10	26	8	6000	CM or Normal	as side guides on later saws
10	30	9	6200	CM or Normal	most popular, esp up to y2000 from Taiwan
12	32	10	6201	CM or Normal	only some older saws

?These bearings are used at v.low speed and low load, so the ABEC rating[2] is not applicable, however the Radial Internal Clearance[3] grading should be considered.
Just measure the bearings ID, OD and Width and pick out the ones you need - jv

[1] Not all mnfr’s follow the international codes for similar size bearings e.g. SKF, who work off IDxODxW.

[2] ABEC scale is a bearing industry standard for manufacturing tolerances on every measurable dimension except internal clearance. Higher ABEC ratings allow those bearings higher operational speeds, in excess of 30,000rpm, but no more load and even less shock resistance. ABEC 1 are cheap and wear out quickly, these are what you will get if you do not ask for better. ABEC 3 or 5 are usually better manufactured and still reasonably inexpensive.? You’ll pay 5-10x as much for ABEC 7 or 9 for absolutely no measurable difference in performance over ABEC 3 in a 4x6. You can even buy an ABEC 9 bearing with C5 radial internal clearance (for high speed roller skates) that is worse for side guide rollers than a much cheaper ABEC 3 with even C3 radial internal clearance.

[3] Radial internal clearance is essentially the amount of up&down movement the bearing will allow.? Less is better for 4x6? guide rollers.

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Re: Replacement blade guide bearings

[1] Not all mnfr’s follow the international codes for similar size bearings e.g. SKF, who work off IDxODxW.

[3] Radial internal clearance is essentially the amount of up&down movement the bearing will allow.? Less is better for 4x6? guide rollers.