2788-2720 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB) · extracted 2026-09-28

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the 2788-2720 model number is decoded

Inch tapered bearings are matched sets, not mix-and-match components: 2788 pairs the 2788 cone with the 2720 cup under the 2700-series boundary plan, and although the same cone shows up against other cups in the catalogue, each pairing yields a distinct assembled width and a distinct rating row.The SKF 2788/2720 is a 38.1×76.2×23.812 mm single-row tapered roller bearing — an inch-series entry with an asymmetric raceway cut for thrust capacity and separable mounting.Numbering ties the bearing to its inch-series envelope: 2788 means a cone and cup matched pair in the 2700-series series — which is why the 38.1×76.2×23.812 mm outline swaps dimensionally with other inch-series bearings of the same code. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. Selection arithmetic: the C0/C ratio is about 1.01 (static 93 kN against dynamic 92.1 kN), typical of a tapered roller sized for axial capacity, and the 10.4 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. Fit selection follows the rotating ring — interference on a rotating cone — and two 2788 units are required to take reversing thrust; keep the induced axial load inside the rated capacity when calculating the pair. Operating context for the 38.1 mm bore: a shaft of this diameter in the medium-bore band typically runs between 30480 and 45720 r/min in real machinery, and the 76.2 mm outside diameter places the housing shoulder at 84 mm outer abutment; the 23.812 mm width and 500 g mass together set the shaft critical speed and the housing resonance check for this 27800-series envelope.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 38.1 mm bore, interference and temperature rise consume clearance inside a preloaded pair; calculate the residual clearance after mounting and at operating temperature — an over-tight 2788 pair heats, loses setting control and smears the roller-rib contact.
• The 2700-series inch series at 38.1 mm bore (76.2×23.812 mm) follows the Timken cone/cup convention; substitutions must match both the cone and cup reference exactly — interchanging with another series or a metric 3xxxx bearing of the same bore changes OD, width and contact angle, so re-run the pair setting and shoulder-diameter checks before swapping.
• A single 2788 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
• Setting is a design value, not an assembly feel: excessive preload in the 2788 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
• Shaft and housing fillets must clear the bearing chamfer so the 23.812 mm-wide cup seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
• The 92.1/93 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
• SKF lists several executions of 2788 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 2788/2720 designation when purchasing and match the execution to the mounting arrangement.