UCFLX06 bearing: complete specifications & equivalents
The UCFLX06 is a JIS B 1559 radial bearing sized 30 x 72 x 42.9 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 | 30 mm |
| Outer diameter D | 72 mm |
| Width B | 42.9 mm |
| Seal / shield | 2RS |
| Basic dynamic load rating C | 28.4 kN |
| Basic static load rating C0 | 15.3 kN |
| Fatigue load limit Pu | 1.09 kN |
| Mass | 1400 g |
| Housing height H | 156 mm |
| Housing overall length L | 95 mm |
| Mounting bolt center distance J | 130 mm |
| Mounting hole diameter N | 16 mm |
| Manufacturer designation | UCFLX06 |
| Standard | JIS B 1559 |
| Catalog version | CAT. No. 2203-3/E 2024 |
| Last verified | 2026-09-25 |
Source: catalog reference (CAT. No. 2203-3/E 2024) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (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 & UCFL-series range
| Bore d | 1.181 in |
|---|---|
| Outer diameter D | 2.835 in |
| Width B | 1.689 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 21 mm |
| Smallest bore in UCFL-series | 12 mm |
| Largest outer diameter in UCFL-series | 300 mm |
| Width range across UCFL-series | 31–145 mm |
| Bore position in UCFL-series (smallest first) | 6 of 25 |
| Bore above smallest UCFL-series size | 18 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| UCFLX06 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range. Brand-specific OEM equivalents pending multi-source data. |
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 UCFLX06 model number is decoded
UCFLX06 belongs to NTN's UCFL line of two-bolt rhombus flanged units, built on a JIS B 1558 UCX06D1 insert in a JIS B 1559 FLX06 housing. On the nameplate, UCFLX06 decodes as a UC wide-inner-ring insert in a FL diamond flange, X-series duty, 30 mm bore; the UCX06D1 designation shows the D1 greasable execution. Boundary data for the 30 mm bore: 156 mm high flange, 95 mm long over the rhombus, 130 mm hole centres for M14 fasteners through 16 mm holes; insert OD is 72 mm. The X section is NTN’s intermediate-duty build: a wider UCX insert with a higher rating sits in a longer, sturdier housing than the 2-series unit at the same bore. The diamond flange carries the shaft square to a vertical face — a welded frame, side plate or gearbox wall — so no base plinth and no shim pack under the bearing are required. The 25–50 mm bore band is the workhorse of industry — belt conveyors, fans, agricultural drives and small process machines — which is why this range has the fullest choice of series and cover options. Sawmill and woodworking machinery mounts this unit on saw arbors and feed rolls, where vibration is continuous and the setscrews must be re-checked after the first hours of running. After the first 24–48 running hours, re-torque both setscrews and the foundation bolts — seating of the inner ring on the shaft and crush of any paint under the feet otherwise leaves the bearing loose at the worst possible time. Basic ratings of the UCX06D1 insert are 28.4 kN dynamic and 15.3 kN static; the assembled UCFLX06 weighs about 1.4 kg.
Typical equipment & failure modes
Common applications
- textile line-shafting
- machine-tool chip conveyors
- belt conveyor head, tail and bend pulleys
- washdown-duty food and pharmaceutical areas using purge relubrication
Known failure patterns
- housing-foot cracking beside an over-torqued or under-supported foundation bolt
- grease starvation on long intervals in hot positions, with the ball set running on dried thickener
- fretting corrosion of the shaft journal under the wide inner ring after years of micro-creep
Selection pitfalls — read before you substitute
- UCFLX06 is located on the shaft by setscrews only; for shock reversing drives consider an adapter-lock insert family instead, since setscrew points indent the 30 mm journal over time.
- In this bore band the temptation is to choose UCFLX06 on shaft size alone; belt pull often dominates the radial load, so rate the unit against the overhung pulley force, not just transmitted power.
- The X insert of UCFLX06 is wider and rated above the 2-series part at 30 mm, but it is not interchangeable with a 3-series unit in a damaged application — check the housing length and bolt centres before swapping.
- As a rhombus flange, UCFLX06 pulls against the frame through only two M14 bolts on 130 mm centres; the mounting plate must be stiff enough not to bend between them under belt load.
Frequently asked questions
How is UCFLX06 locked to the shaft, and how tight should the setscrews be?
The UCX06D1 insert uses two collar setscrews on the 30 mm shaft. Tighten them to NTN's torque table for this bore size in sequence — half torque on the first, full on the second, then back to the first — and re-torque after the first 24–48 running hours once the collar has seated.
When should I choose a rhombus flange unit like UCFLX06 instead of a pillow block?
Choose the UCFLX06 two-bolt flange when the 30 mm shaft meets a vertical frame or side plate: the diamond housing bolts flush with two M14 bolts on 130 mm centres. A UCP pillow block is used when the shaft runs above a horizontal mounting surface.
What are the dimensions of an UCFLX06 mounted bearing?
UCFLX06 takes a 30 mm shaft (insert UCX06D1, 72 mm OD) and has a unit mass of about 1.4 kg. Flange figures: height H 156 mm, length L 95 mm, bolt centres J 130 mm, holes 16 mm for M14 bolts.
What does the UCFLX06 designation mean?
UC identifies the wide-inner-ring, setscrew-locking ball bearing insert; FL the two-bolt rhombus flange housing; X is the duty series; the last digits encode the 30 mm bore. UCFLX06 is built from housing FLX06 plus insert UCX06D1 (D1 = greasable).
Reviewed & verified by the MPN Base engineering desk against source catalog CAT. No. 2203-3/E 2024 on 2026-09-25. Read our editorial & correction policy.