Gearbox layshaft FAG ball bearing

Hi All.
I am usually to use the FAG 6203TB.P63.C3 balls bearing, those sugest by Mike Hemmings.
Bought new one but they havent the final code .P63.C3.
Bought one time also FAG 6203TB.P63 without C3 final.
Question is if they are really the same or only seem.
Thank you.
Piero

Hi Piero

I'll try and help.

The 'P63' part of the designation means as follows:
P63=Combination Of P6 (Dimensional And Running Accuracy To ISO Tolerance Class 6 (Better Than Normal)) And C3 (Internal Clearance Larger Than Normal).

So if not indicated as P63 the bearing will be in a lower tolerance class and will have the normal internal clearance Cn. I'm fairly sure that C3 tolerance is favoured for this use.

Based on Mick's experience I'd try and exchange the bearing for the correct one.

Just to confuse things the correct bearing may also be designated 6203-TB-P6-C3.
Hope this helps.
Andy

DevonNorton said:

Hi Piero

I'll try and help.

The 'P63' part of the designation means as follows:
P63=Combination Of P6 (Dimensional And Running Accuracy To ISO Tolerance Class 6 (Better Than Normal)) And C3 (Internal Clearance Larger Than Normal).

So if not indicated as P63 the bearing will be in a lower tolerance class and will have the normal internal clearance Cn. I'm fairly sure that C3 tolerance is favoured for this use.

Based on Mick's experience I'd try and exchange the bearing for the correct one.

Just to confuse things the correct bearing may also be designated 6203-TB-P6-C3.
Hope this helps.
Andy

Click to expand...

Hi.
Edit my topic.
What the differences between FAG 6203TB.P63 with and without C3?
Thank you so much.
Piero

pierodn said:

What the differences between FAG 6203TB.P63 with and without C3?

Click to expand...

The latest bearings are marked P6.C3 instead of P63 possibly because P6.C3 is easier to understand.

"6203-TB-P63"
" 6203-TB-P6-C3"

CN and C3 are the internal clearance.
For the big crankshaft roller bearings it is very important based on all the engines I have built.
For the gearbox bearing, IMO, it is not an issue at all.

dynodave said:

For the gearbox bearing, IMO, it is not an issue at all.

Click to expand...

Although all FAG 6203TB.P6 bearings appear to be C3 as I haven't found one that isn't, only "Standard precision" 6203TB.

Hi All,
and thank you so much for your kindly help.
I have in the hand the FAG:

6203-TB-P6-C3 made in Korea;​

6203-TB-P6 made in Germany;​

6203-TB made in Portugal.​

Easy to find 6203-TB and 6203-TB-P6, not the C3.
Sorry, can i use the 6203-TB-P6 (without C3)?.
Piero

dynodave said:

CN and C3 are the internal clearance.
For the big crankshaft roller bearings it is very important based on all the engines I have built.
For the gearbox bearing, IMO, it is not an issue at all.

Click to expand...

So Sorry,
what means IMO?.

pierodn said:

what means IMO?.

Click to expand...

Generally means 'In my opinion'.

pierodn said:

Easy to find 6203-TB and 6203-TB-P6, not the C3.

Click to expand...

pierodn said:

Sorry, can i use the 6203-TB-P6 (without C3)?.

Click to expand...

That is something for you to decide.


If P6 is standard (CN) clearance:
"00 FIT (ed. CN)"This grade of diametrical clearance is intended for use where only one ring is made an interference fit and there is no appreciable loss of clearance due to temperature difference. Ball journal bearings for general engineering applications are usually of this clearance"

When to use C3:
"000 FIT (ed. C3) "This grade of diametrical clearance should be used when both rings of a bearing are made an interference fit, or when only one ring is an interference fit but there is likely to be some loss of clearance due to temperature differences."