NA56424A Precision Class 3 Timken Tapered Roller Bearing Cone (0926)

Timken NA56424A (Precision Class 3) is a special/precision inner-ring (cone) for an imperial 56000-series tapered roller bearing assembly, typically paired with a 56650D double cup (TDO or similar double-row configuration). Key dimensions Bore (d): 4.2497 in (107.942 mm) Cone width (B): 1.6250 in (41.275 mm) Max shaft fillet radius (R): 0.14 in (3.5 mm) Cone Net weight: 4.245 lbs. NA56424A can pair with double cups corresponding to related 56000-series parts (e.g., those used with NA56393-SW). When used that way, subtract 0.2500 in (6.350 mm) from the catalog T-width values. Related standard 56000-series ratings (for context)The closely related NA56425SW / 56650D (or 56425 / 56650) parts share the same series and cup and have published ratings of this order: Dynamic radial C1 (1 million rev, two-row): ~88,600 lbf (394,000 N) Dynamic radial C90 (90 million rev, one-row): ~13,200 lbf (58,700 N) Dynamic thrust Ca90: ~11,200 lbf (50,000 N) K factor: 1.18 e (ISO): 0.50 Y1 / Y2: ~1.36 / 2.02 Static radial C0 (typical single-row equivalent): ~79,700 lbf Exact load ratings, stiffness, and speed limits for the Precision 3 NA56424A assembly can differ slightly because of the special cone width/bore and tighter class; confirm with a Timken catalog sheet or application engineer. Other notes Design: Tapered roller, typically TDO (double outer ring) or TNA-style double-row assembly, stamped-steel cage, open, uncoated steel. Precision Class 3 applies to inch tapered rollers (comparable in intent to higher ABMA/ISO precision classes). Applications: Precision machine-tool, spindle, or other applications needing tighter running accuracy than standard Class 2.