2788 Bearing Dimensions
2788 inch tapered roller bearing cone, paired with the 2720 cup: 38.1 mm (1.500 in) bore, 76.2 mm OD, 23.812 mm width (FULI catalog). Quote.
2788 specifications
| Cone bore d | 38.1 mm (1.500 in) |
|---|---|
| Cone width B | 25.654 mm |
| Matching cup | 2720 |
| Cup outside diameter D | 76.2 mm (3.000 in) |
| Total width T | 23.812 mm (0.937 in) — assembled width of cup and cone |
| Seal / shield options | Open (cup and cone, no seals) |
| Material | GCr15 chrome bearing steel (rings and rolling elements) |
| Radial clearance | Set during mounting (adjustable, not a C-class value) |
| Load ratings | See the cone and cup pairs table below |
2788 cone and cup pairs
| Cone | Cup | Bore d | OD D | Width T | Cr (kN) | C0r (kN) |
|---|---|---|---|---|---|---|
| 2788 | 2720 | 38.1 mm (1.500 in) | 76.2 mm (3.000 in) | 23.812 mm (0.937 in) | 80.4 | 102 |
Dimensions from FULI's catalog. A cone (inner ring with rollers and cage) and a cup (outer ring) make up one bearing; the pairs above are the matching numbers listed in FULI's catalog. Values from FULI's catalog; confirm for your application.
How to read the 2788 designation
| Segment | Meaning |
|---|---|
| 2788 | Designation breakdown not available for this model. |
2788 interchange
2788 is an inch tapered roller bearing cone. Inch tapered roller bearings are ordered by cone number and cup number. Most makers use the same cone and cup numbers for the same size, but always check the cup number as well. Send us the numbers on your old bearing and we confirm the match before quoting.
Brand names are trademarks of their respective owners. FULI is not affiliated with, authorized by or endorsed by these companies. Part numbers are shown for interchange reference only. FULI dimensions, load ratings and speeds come from the FULI catalog.
2788 compared with nearby cone sizes
The 2788 cone has a 38.1 mm (1.500 in) bore and a cone width of 25.654 mm. FULI's catalog pairs it with cup 2720 (76.2 mm outside diameter, 23.812 mm total width).
The next smaller cone on this site is HM89449, with a 36.512 mm bore (1.59 mm smaller) and cup HM89410.
The next larger is LM29748, with a 38.1 mm bore (0 mm larger) and cup LM29710.
Cup 2720 is also listed with 2790, so the same housing bore can take a different cone if the shaft size changes.
The metric tapered bearing on this site closest in bore is 32008 (40 × 68 × 19 mm). Its sizes differ from the 2788 pair, so the two are not interchangeable; it is given only as a size reference.
| Cone | Cup | d × D × T | Cr (kN) |
|---|---|---|---|
| L68149 | L68110 | 34.988 × 59.131 × 15.875 mm | 34.9 |
| JL68145 | L68111 | 35 × 59.974 × 15.875 mm | 34.9 |
| HM89449 | HM89410 | 36.512 × 76.2 × 29.37 mm | 80.1 |
| 2788 | 2720 | 38.1 × 76.2 × 23.812 mm | 80.4 |
| LM29748 | LM29710 | 38.1 × 65.088 × 18.034 mm | 43.4 |
| LM29749 | LM29711 | 38.1 × 65.088 × 19.812 mm | 43.2 |
| U399 | U360L | 39.688 × 73.025 × 19.395 mm | 55.1 |
Sizes and Cr from FULI's catalog; — = not listed on this site.
2788 load ratings
2788/2720 has a dynamic load rating Cr of 80.4 kN and a static rating C0r of 102 kN in FULI's catalog. The ratings belong to the cone and cup as a pair; a different cup changes them.
Speed limits and weights for inch cones are not listed in the catalog; ask us and we send them with the quotation.
Values from FULI's catalog; confirm for your application.
2788 size in inches and millimetres
2788 is made to inch sizes. The 38.1 mm bore is 1-1/2 in. The millimetre values in the catalog are conversions of the inch sizes.
| Dimension | Millimetres | Inches |
|---|---|---|
| Cone bore d | 38.1 mm | 1.5000 in |
| Cup outside diameter D (2720) | 76.2 mm | 3.0000 in |
| Total width T | 23.812 mm | 0.9375 in |
| Cone width B | 25.654 mm | 1.0100 in |
| Cup width C | 19.05 mm | 0.7500 in |
Converted at 1 in = 25.4 mm and rounded to four decimals.
Mounting 2788 (general guidance)
General guidance, not a FULI specification: on a turning shaft the cone is a tight fit on the shaft and the cup a lighter fit in the housing, so the cup can be moved when the bearing pair is adjusted. Inch bearing fits are given as shaft and housing limits in inches in the bearing makers' tables; follow the drawing of your machine.
Tapered roller bearings carry radial load and axial load in one direction, so 2788 is normally used as one of a pair, and the end play or preload is set at mounting.
If the outer ring turns and the shaft stands still, as in an idler pulley or a wheel hub, the fits are reversed: the housing gets the interference fit (for example N7 or P7) and the shaft a sliding one (g6 or h6).
Grease for 2788
FULI supplies tapered roller bearings rust-protected and normally without grease; grease is packed in when the bearing is mounted. Relubricating 2788/2720 from the side takes about 9.07 g each time by the formula in our grease calculator: 0.005 × D × T = 0.005 × 76.2 × 23.81.
How FULI supplies 2788
2788 is supplied as a cone, as a cup or as a complete cone and cup pair, as your order states. Where an order states a requirement for the total width T (23.812 mm for 2788/2720), each set is checked on a height gauge before packing.
Rings are marked with a brand you are authorised to use, with the FULI brand, or left neutral, as your order states. The box is printed with the model, precision class and brand.
Inquiries that give only one number are the usual cause of a wrong quote, so write both the cone and the cup number, for example 2788/2720.
Tools and guides for 2788
Typical applications
- Vehicle wheel hubs and axles
- Gearboxes and reducers
- Agricultural machinery
- Conveyor pulleys
FAQ
What size is 2788 in mm?
The 2788 cone has a 38.1 mm bore (1.500 in). With cup 2720 the bearing is 38.1 × 76.2 × 23.812 mm (d × D × T).
What is the difference between 2788 and LM29748?
LM29748 has a 38.1 mm bore against 38.1 mm for 2788, and pairs with cup LM29710 (38.1 × 65.088 × 18.034 mm) instead of 2720 (38.1 × 76.2 × 23.812 mm). The two are not interchangeable; order by the numbers on the old cone and cup.
How much grease does 2788/2720 need?
About 9.07 g each time it is relubricated from the side (0.005 × 76.2 × 23.81). FULI ships it rust-protected without grease, so the first fill is made at mounting.
Which cup goes with the 2788 cone?
FULI's catalog pairs the 2788 cone with cup 2720. Tell us whether you need the cone, the cup or both when you send the inquiry.
Is 2788 the same size across brands?
2788 is an inch tapered roller bearing cone number. Most makers use the same cone and cup numbers for the same size, but check the cup number too. Send us the numbers on your old bearing and we confirm the match.