6315-2RS-NTN bearing: complete specifications & equivalents
The 6315-2RS-NTN is a ISO 15 radial bearing sized 75 x 160 x 37 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 160 mm |
| Width B | 37 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 126 kN |
| Basic static load rating C0 | 77 kN |
| Fatigue load limit Pu | 5.55 kN |
| Limiting speed (mechanical) | 2900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3020 g |
| Manufacturer designation | 6315LLU |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) |
| Last verified | 2026-09-25 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & 6300-series range
| Bore d | 2.953 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.457 in |
| ISO bore code | 15 |
| Radial section height (D−d)/2 | 42.5 mm |
| Smallest bore in 6300-series | 2 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 3–95 mm |
| Bore position in 6300-series (smallest first) | 22 of 40 |
| Bore above smallest 6300-series size | 73 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6315-2RS-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6315-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 315 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 315-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
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-NTN model number is decoded
In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6315 carries bore code 15 = 75 mm. Outside diameter 160 mm and width 37 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 75 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6315LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.
Typical equipment & failure modes
Common applications
- gearboxes and speed reducers
- conveyor drives
- material-handling equipment
- industrial fans
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- brinelling from static overload or hammering during mounting
- false brinelling from vibration while the shaft is stationary
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-NTN 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.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 160 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6315-2RS-NTN.
- The housing bore for the 160 mm OD should be round within IT7; an oval bore pinches the outer ring of 6315-2RS-NTN and shows up later as two-point loaded raceway wear.
- NTN catalogues the contact-sealed version as 6315LLU (suffix LLU), 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.
- At 75 mm bore 6315 is in NTN'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 NTN channel if the application sees impact loads.
- NTN lists the grease limiting speed at 2900 r/min for 6315; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
- At 126 kN dynamic load rating (C) and 77 kN static (C0), 5.55 kN fatigue load limit Cu, 6315 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN 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 3020 g (3.0 kg), 6315 needs mechanical handling for mounting; NTN 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 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 126/77 kN load ratings, 5.55 kN fatigue load limit Cu NTN lists the grease limiting speed at 2900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 3020 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6315LLU 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.
- Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.
- NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6315 is listed.
Frequently asked questions
What are the dimensions of a 6315-2RS-NTN bearing?
A 6315-2RS-NTN deep-groove ball bearing has a 75 mm bore, 160 mm outer diameter and 37 mm width (2.953 × 6.299 × 1.457 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased.
Are 6315 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6315 uses the same ISO 15 envelope (75×160×37 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar).
What internal clearance does 6315-2RS-NTN have?
Unless a clearance suffix says otherwise, 6315-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6315 and verify the residual clearance after mounting.
What is the NTN suffix for a sealed 6315?
NTN uses suffix LLU for the contact rubber seal (catalogue number 6315LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 75×160×37 mm ISO 15 envelope.
Does NTN offer 6315 with C3 clearance?
Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6315LLU is the correct choice.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) on 2026-09-25. Read our editorial & correction policy.