51117 bearing: complete specifications & equivalents
The 51117 is a ISO 104 radial bearing sized 85 x 110 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 85 mm |
| Outer diameter D | 110 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 46 kN |
| Basic static load rating C0 | 150 kN |
| Fatigue load limit Pu | 6.8 kN |
| Limiting speed (mechanical) | 2100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 444 g |
| Manufacturer designation | NTN 51117 |
| Standard | ISO 104 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); 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 & 51100-series range
| Bore d | 3.346 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 0.748 in |
| ISO bore code | 17 |
| Radial section height (D−d)/2 | 12.5 mm |
| Smallest bore in 51100-series | 10 mm |
| Largest outer diameter in 51100-series | 640 mm |
| Width range across 51100-series | 9–85 mm |
| Bore position in 51100-series (smallest first) | 18 of 46 |
| Bore above smallest 51100-series size | 75 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51117-SKF | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
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 51117 model number is decoded
From the light-section 51100 thrust family, 51117 measures 85 mm through the shaft washer, 110 mm over the outside and 19 mm in assembled height. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 17 encodes the 85 mm bore (bore code x 5). The washer section here is 12.5 mm of radial height, and the catalogue couples it with Ca 46 kN / C0a 150 kN. For a 85 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts.
Typical equipment & failure modes
Common applications
- crusher main-shaft thrust supports
- large rotary-table and index-table thrust rings
- vertical water-pump and turbine thrust blocks
- large crane hook and swivel assemblies
Known failure patterns
- ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this
- fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track
- rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only
- lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced
- lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced
Selection pitfalls — read before you substitute
- At 85 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.
- The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 85 mm bore it gives up load to gain OD, height and limiting-speed headroom.
- A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.
- The 2,100 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.
- The C0a of 150 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.
- The Ca 46/C0a 150 kN ratings and 6.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51117; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 51117?
51117 is a single-direction thrust ball bearing to ISO 104: 85 mm shaft-washer bore, 110 mm outside diameter, 19 mm stack height (3.346 x 4.331 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 46 kN, C0a 150 kN and a 6.8 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 3,000 r/min; mass about 444 g.
How is the 51117 designation structured?
511 is the dimension series (light-section 51100 thrust family); 17 encodes the 85 mm bore (bore code x 5). The 110 mm OD and 19 mm height follow the ISO 104 boundary plan for that series.
Can 51117 carry radial load or reversing thrust?
No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution.
Why does NTN specify a minimum axial load for 51117?
At the 2,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling.
What should be checked before substituting another make for 51117?
The 85/110/19 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 46 kN / C0a 150 kN, the speed figures and the shaft/housing washer identification against the donor catalogue.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.