FAG6005.TB.P63Single Row Deep Groove Ball Bearing 25x47x12 mm, P6 Tolerance with C3 Internal Clearance

Product Description

What this part is:

A single-row deep groove ball bearing, 25 mm bore × 47 mm outside diameter × 12 mm width, in the 6000 light series. Deep groove ball bearings take radial load with moderate axial load in either direction and locate a shaft on their own. This one is specified with a combined tolerance and clearance suffix, which is the interesting part of the designation.

Decoding the designation:

• 6005 – ISO base number for the single-row deep groove ball bearing with the 25 × 47 × 12 mm envelope.
• TB – a FAG cage code. The TB family is associated with a fabric-reinforced phenolic (laminated textile) cage, machined and typically ball-guided, of the type used on higher-speed and spindle bearings. This should be confirmed against the physical cage before being relied on, so it is published here as an identification rather than a certified specification.
• P63 – a combined FAG code, not a single class. It means dimensional and running tolerance to P6 together with radial internal clearance class C3 (greater than normal). This is a real and useful decode: the two halves of the code control different things and both matter.

Correcting the source data:

The previous listing described the part as ABEC3. ABEC 3 corresponds broadly to ISO P6 in tolerance terms, so the claim is in the right neighbourhood, but the designation on the bearing says P6 and the two systems are not interchangeable class for class. The tolerance is stated here as P6, taken from the part number itself, rather than repeating the ABEC figure. The previous title and description also stated the listing included 10 pieces, which does not match the recorded stock. See the quantity section below.

What P6 with C3 means in practice:

P6 tightens the bore, outside diameter, width and running accuracy relative to the normal P0 class. That is what you want when the shaft has to run true — less runout means less vibration and a smoother, quieter drive at speed.

C3 works in the opposite direction internally: more free radial play in the unmounted bearing than normal. Clearance is consumed once the bearing is installed. A press fit on the shaft expands the inner ring and takes clearance away, and a hot inner ring grows more than a cooler outer ring, taking more away again. C3 leaves headroom so that after those losses there is still working clearance at running temperature.

Pairing them is deliberate: accurate geometry, plus enough internal room that a tight fit or a temperature gradient does not preload the bearing into early failure. The mismatch cuts both ways. Fit a C3 bearing into a normal-clearance application and it keeps too much play when running — a narrower load zone, fewer balls sharing the load, more noise and higher raceway stress. Fit a normal-clearance bearing where C3 was specified and on a hot or tightly fitted shaft it loses all its clearance, goes into preload, generates its own heat and seizes.

Published ratings and mounting data:

Figures below are catalogue values for the 6005 envelope in open form. They come from distributor catalogue data rather than a Schaeffler publication for this exact suffix, so treat them as provisional. Note also that a phenolic cage generally lowers the permissible operating temperature relative to a steel cage, so if the TB cage is confirmed, temperature limits are set by the cage rather than the steel.

• Basic dynamic load rating (C): approximately 11.9 kN
• Basic static load rating (C0): approximately 6.55 kN
• Fatigue load limit (Pu): approximately 0.275 kN
• Reference speed: approximately 32 000 r/min

The static rating sitting below the dynamic rating is expected on a deep groove ball bearing and is not a data error — the two figures describe different failure modes.

Quantity and configuration:

No total piece count is published for this listing. The previous title advertised 10 pieces while the stock record shows a different figure, and rather than pick one of two conflicting numbers, the count is being resolved by a physical shelf count. Confirm the quantity before ordering against a multi-bearing job.

Fitting notes:

Press only against the ring taking the interference fit so no load passes through the ball complement. If the TB phenolic cage is confirmed, avoid steam cleaning, hot solvent baths or induction heating well above the cage rating — phenolic cages will not tolerate the temperatures a steel cage shrugs off. Check the machine’s specified clearance class before substituting; a plain 6005 or a 6005 P6 without the C3 half of the code is not the same bearing in service.

Interchange guidance:

The 6005 base number is universal, so SKF 6005, FAG 6005, NSK 6005, NTN 6005, Koyo 6005 and Timken 6005 all share the 25 × 47 × 12 mm envelope. The differentiators are cage material, tolerance class and clearance class. A like-for-like substitute needs P6 tolerance and C3 clearance together, and if the application depends on the phenolic cage’s speed capability, a steel-caged equivalent is not a straight swap.