The 63/28/25 (28×63×25 mm / 1.102×2.480×0.984 in) is a non-standard deep groove ball bearing manufactured to a customer-specific dimension outside standard ISO sizing. This is a real, recurring size we manufacture for OEM replacement — the "63/28/25" designation reflects the series and key dimensions rather than an official catalog part number.

No common standard catalog bearing matches the complete 28 × 63 × 25 mm dimensional combination. This makes the bearing difficult to replace with an off-the-shelf standard bearing and is why an OEM-matched replacement may be required.

Manufactured to match original OEM tolerances, load balance, sealing performance, and internal clearance, the 63/28/25 is built as a true drop-in replacement — no shaft grinding, housing machining, or shimming required.

Note: This is a different size from our 63/28 2RS C3 (28×68×18 mm) and 63/28X (28×72×18 mm). All three belong to the broader 63/28 non-standard family but are not interchangeable — confirm your equipment's exact OD and width before ordering.

Technical Specifications

Available Configurations

• 63/28/25 Open Type — no seal, for high-speed or easy-maintenance applications

• 63/28/25 ZZ — double metal shield

• 63/28/25 2RS — double rubber seal, dustproof and waterproof (most common configuration)

• Optional C3 / C4 internal clearance — for high-temperature and high-vibration operating conditions

Why This Size Is Difficult to Replace

The complete 28 × 63 × 25 mm combination is not a common standard deep groove ball bearing size. Standard bearings with similar dimensions may differ in bore, outer diameter, or width, making them unsuitable as direct replacements.

Using a bearing with the wrong bore can result in an improper shaft fit. A mismatched outer diameter can cause incorrect housing fit, while an incorrect width can create axial positioning problems.

For legacy OEM equipment, these dimensional differences can lead to vibration, abnormal noise, uneven load distribution, and premature bearing wear. The 63/28/25 is manufactured to match the required OEM dimensions without shaft grinding, housing machining, or shimming.

Typical Applications

• Legacy Industrial Equipment: Discontinued OEM machinery built with this exact cavity size

• Heavy-Duty Transmission Assemblies: Applications with specific housing depth, axial positioning, or load-distribution requirements

• Agricultural Machinery: Tractors, harvesters, and transmissions operating in dusty, high-vibration conditions

• Custom & Export-Grade Mechanical Units: Equipment manufactured to non-ISO specifications

Cross-Reference & Interchangeability

The 28×63×25 mm dimension is not covered by any standard ISO or ABMA catalog size. It corresponds to a customer-specific OEM cavity, most commonly found on legacy or imported equipment.

If you have a sample, drawing, worn part, or the equipment's model number, our engineering team can measure and confirm the exact specification — including which variant within the 63/28 family your equipment requires — before you order.

Customization Options

• Material: GCr15 chrome steel (standard), stainless steel options available

• Seal Type: Open, ZZ, or 2RS

• Clearance: Standard, C3, or C4

• Precision: P0 standard, P6 custom

• Lubrication: Custom grease options for high-temperature or low-noise requirements

Frequently Asked Questions (FAQs)

Q: Is "63/28/25" an official bearing part number?

A: No. It reflects the series and key dimensions (28 mm bore, 25 mm width) rather than an official catalog code. The exact specification is 28×63×25 mm, manufactured to match your OEM requirements.

Q: How is this different from the 63/28 2RS C3 or 63/28X?

A: All three are non-standard 63/28-family bearings with the same 28 mm bore, but different outer diameters and widths — 68×18 mm, 72×18 mm, and 63×25 mm respectively. They are not interchangeable. Confirm your equipment's exact OD and width before ordering.

Q: Can I replace the 63/28/25 with a standard bearing of similar size?

A: Not necessarily. A similar-looking bearing may have a different bore, outer diameter, or width and therefore may not fit the original shaft and housing correctly. For OEM replacement, we recommend confirming all three dimensions — 28 × 63 × 25 mm — before ordering.

Q: What is the lead time for custom orders?

A: Standard samples are available in 7–10 days; mass production lead time is 15–25 days, depending on order quantity and customization requirements.

Q: Do you offer stainless steel versions?

A: Yes, stainless steel material options are available for corrosion-resistant applications — let us know your operating environment when ordering.

Call to Action

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