6315-2RS-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 6315-2RS-NSK model number is decoded

6315-2RS 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 medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 15 by five gives the 75 mm bore; the 160 mm outside diameter and 37 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 6315DDU (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 6315 against the shaft shoulder while it cools so the ring cannot creep back.
• The 63xx medium section at 75 mm bore gains dynamic rating through larger rolling elements on a 160 mm OD; the penalty is mass and a lower limiting speed than the 6215 — do not specify it for speed-critical shafts.
• Contact seals add drag and heat: 6315-2RS-NSK runs slower and cooler-limited than the open 6315; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
• Heat is the enemy of the sealed 6315-2RS: 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.
• 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 6315-2RS-NSK.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 37 mm-wide ring of 6315-2RS-NSK drags the lip and overheats it.
• NSK catalogues the contact-sealed version as 6315DDU (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 6315 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.
• At 125 kN dynamic load rating (C) and 77 kN static (C0), 6315 is a heavy-load NSK bearing for industrial gearboxes and large conveyors; NSK expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.
• At 3080 g (3.1 kg), 6315 needs mechanical handling for mounting; NSK recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.
• The 75×160×37 mm envelope of 6315 gives a D/d ratio of 2.13 and 42.5 mm radial section height — a heavy NSK section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
• The 125/77 kN load ratings, mass 3080 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6315DDU on the 75×160×37 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6315 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 supplies its sealed units pre-greased for general duty between roughly -10 and +110 °C; low-temperature, food-grade and high-temperature fills are special executions — ask at order time, because DDU/VV units are not designed to be opened and repacked.
• NSK's VV non-contact seal keeps frictional torque close to the open 6315; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.