687-672 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 687-672 model number is decoded

Two catalogue entries share the 687 cone but use different cups; this one, 687, takes the 672 cup and is ground for the resulting 168.275 mm OD / 41.275 mm width envelope. Selecting a sibling cup produces a different boundary plan and a different order number, so the full designation is required at purchase.SKF 687 (SKF 687/672) is the 675-series tapered roller choice for a 101.6 mm shaft — one row of tapered rollers on an asymmetric raceway inside the 168.275×41.275 mm envelope.Reading the designation: 687 follows the Timken-style inch convention — the cone (inner ring with rollers) and cup (outer ring) are quoted as a pair separated by a slash, and the 675-series code identifies the dimensional series. The 101.6 mm bore, 168.275 mm OD and 41.275 mm width are the metric equivalents of the inch boundary dimensions. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. With C 288 kN and C0 365 kN, the 687 pair-sizing check is dominated by the axial share: keep the equivalent load P below the rating at the required L10, remembering one bearing alone cannot cover reversing thrust at 3,800 r/min. A single 687 locates the shaft in one axial direction only; mount it against a second bearing in O (back-to-back) or X (face-to-face) arrangement, and set the running clearance by the mounting procedure — not by feel. Cross-section geometry: the 33.3 mm half-section ((168.275−101.6)/2) of this 68700-series unit places the roller large-end pitch diameter at roughly 134 mm, and the 41.275 mm axial width is split between cone (23 mm) and cup rib (19 mm) — a geometry that sets the contact angle and, with the 3450 g rotating cone mass, the critical speed at which cage-roller imbalance begins.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Mount the 101.6 mm bore 687 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
• The 675-series inch series at 101.6 mm bore (168.275×41.275 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.
• At the 288 kN rating of 687, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 3,800 r/min speed end and heavier preload only where moment stiffness dominates.
• The tapered contact angle creates an induced axial load under pure radial force; include it in the 687 rating calculation (and account for it in both bearings of a pair) or the unloaded bearing skids its rollers.
• The 687 shares its ISO 355 envelope with other tapered bearings of the same code but is not a drop-in replacement for a ball bearing: it cannot run effectively under pure radial load without a minimum axial load, and a deep-groove bearing cannot replace its combined-load duty.
• The 288/365 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 687 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 687/672 designation when purchasing and match the execution to the mounting arrangement.