344-332 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 344-332 model number is decoded

Cross-section geometry: the 20.0 mm half-section ((80−40)/2) of this 34400-series unit places the roller large-end pitch diameter at roughly 60 mm, and the 21 mm axial width is split between cone (12 mm) and cup rib (9 mm) — a geometry that sets the contact angle and, with the 470 g rotating cone mass, the critical speed at which cage-roller imbalance begins. Housing and abutment design flows from the cup: in 344 the 332 cup fixes the 80 mm OD, the outer-ring face position and the rib shoulder that the rollers contact under thrust, while the 344 cone determines the 40 mm shaft interface; the 21 mm width is the assembled pair value.In SKF catalogue PUB BU/P1 17000, 344 appears as SKF 344/332: an open, single-row tapered roller bearing in the 335-series, supplied with a pressed-steel cage as standard.The 335-series series assigns 40 mm bore, 80 mm OD and 21 mm width to 344; the cone and cup references are not interchangeable with other inch-series pairs even when the bore matches, because the cup profile and rib geometry are series-specific. The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. ); it is the dimensional series, not a separate part number. With C 87.6 kN and C0 80 kN, the 344 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 8,500 r/min. A single 344 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.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 40 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 344 pair heats, loses setting control and smears the roller-rib contact.
• The 320 series at 40 mm bore (80×21 mm) is the low-friction, higher-speed section; it carries less thrust than a 302 of the same bore, so verify the axial load share before swapping.
• A single 344 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.
• A single 344 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.
• Open 344 units need application-supplied sealing and a defined EP lubricant supply; the roller-rib contact is the first to fail when the additive film breaks down.
• The 87.6/80 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 344 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 344/332 designation when purchasing and match the execution to the mounting arrangement.