61815-2RS-NSK bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24

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 61815-2RS-NSK model number is decoded

61815-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 15 by five gives the 75 mm bore; the 95 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 75 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NSK's contact-seal catalogue number is 6815DDU (suffix DDU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 75 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61815 against the shaft shoulder while it cools so the ring cannot creep back.
• The 618xx thin section at 75 mm bore has only a 10.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6215.
• Heat is the enemy of the sealed 61815-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.
• Never wash a sealed 61815-2RS-NSK in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
• Measure the shaft, do not trust the drawing: a 75 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61815-2RS-NSK.
• Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.
• NSK catalogues the contact-sealed version as 6815DDU (suffix DDU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing. NSK's DDU lip design is single-lip contact, so grease life is longer than VV but drag torque is higher.
• At 75 mm bore 61815 is in NSK's upper general-purpose range; the pressed-steel cage is standard, but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NSK channel if the application sees impact loads.
• NSK rates 61815 at 13.8 kN dynamic (C) and 13.9 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.
• At 149 g, 61815 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
• The 75×95×10 mm envelope of 61815 gives a D/d ratio of 1.27 and only 10.0 mm radial section height — this is an ultra-thin section in NSK's E1103 catalogue where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.
• The 13.8/13.9 kN load ratings, mass 149 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6815DDU on the 75×95×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61815 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
• NSK does not recommend washing new shielded or sealed bearings; the rust-preventive film on open units is compatible with standard lithium greases and needs no removal unless the application demands a special fill.
• Keep NSK bearings in the original packaging until fitting: the wrapper carries the production lot, and the unopened shelf life of greased sealed units is typically quoted at three to five years in dry, vibration-free storage.