Fuji Bearing Lock Nuts

Used to locate and secure bearings or other shaft components into place, our range of bearing lock nuts were developed to simplify and reduce the overall cost of bearing assemblies.

Quality secure bearing locking solutions.

Bearing lock nuts are used to locate, secure, and pre-load bearings in position on a shaft, but may also be used to secure other shaft mounted components, such as gears and pulleys. The Fuji lock nut represents the pinnacle of design, eliminating the need for machined keyways and improving rotational balance.

See the full Fuji Locknuts Catalogue!

Fuji bearing lock nut with visible grooves and threads, used for securing bearings and shaft components.
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Markets

IEC have a range of mechanical solutions to suit a broad spectrum of markets and applications, from aerospace to skateboards.

Markets

IEC have a range of mechanical solutions to suit a broad spectrum of markets and applications, from aerospace to skateboards.

Markets

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Case Studies

We act as partners, making our customers’ engineering challenges ours to solve, removing stress and freeing up time to turn ideas in to innovation.

Product:
Bearings
Application:
Peristaltic pump
Challenge:
Peristaltic pumps use occlusion rollers and positive displacement to feed fluid in industrial and medical applications, regulating flow and eliminating the need for valves. Bearings fitted in occlusion rollers have a cycle of coming on and off load with the potential to skip.
Solution:
It is important to select a bearing with high quality machining of its raceways to allow the bearing to readily accept these changes in state.
Bearings for Electric Motors
Product:
Bearings
Application:
Co-ordinate measuring machines (CMM)
Challenge:
5-axis measurement represents the biggest step-change in measurement capability ever introduced, delivering unprecedented speed and measurement flexibility, whilst avoiding the speed versus accuracy compromises inherent in conventional techniques.
Solution:
Duty of CMMs is generally low hence there is intermittent operation of bearings. Machines do require high reliability so products are tested and developed continuously, meaning technical support from bearing OEMs is critical. Some bearings are supplied with specific profiled outer ring designs.
Product:
Bearings
Application:
High pressure pure air generators
Challenge:
High pressure pure air generators are designed to replace rechargeable gas bottles on modern military aircraft. The system draws in atmospheric air to provide a continuous supply of high-pressure pure air, which results in unlimited mission duration and eliminates the logistics burden associated with gas bottles.
Solution:
For critical applications, reliability and resilience is paramount. IEC supplied components are capable of operating with high degrees of accuracy under extreme load.
IEC precision engineering components catalogue.

Download technical documents and brochures.

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Fuji Bearing Locknuts Catalogue

FUJI BEARING LOCKNUTS

The Fuji Fine-U-Nut was developed to simplify the assembly and reduce costs involved in securing ball bearings.

The manufacturer has more than 30 years experience in locknut technology and their factory is ISO 9001 approved.

Construction & Function

The Fuji Bearing Locknut is a one piece item where the locking function is performed by a spring peened into the top of the nut. In use the spring bears on the flank of the shaft thread with force (P) generating reaction force (P’) in the screw threads with a resulting high friction torque (prevailing torque). The nut therefore remains locked in position. 

Fuji Bearing Locknuts are manufactured in carbon, high carbon and stainless steel and are a stock item at IEC in sizes from M10 to M100.

KEY BENEFITS

  • Unique slim body design
  • Secure locking without keyway and tab washer
  • Improved shaft strength and balance
  • Simple infinite adjustment
  • Re-usable up to 100 times
  • Sizes from M10 to M150
  • Carbon, high carbon and stainless steel versions
  • Resists vibration and shock
  • Equally effective for rotation in either direction even with rapid reversals
  • One piece construction reduces stock and allows simpler, quicker assembly

PROOF LOAD & MAXIMUM TIGHTENING TORQUE

Part NoSS (Low Carbon Steel)SC (High Carbon Steel)SUS (Stainless Steel)
Prevailing Torque (Nm)Proof Load (N)Max Tightening Torque (Nm)Proof Load (N)Max Tightening Torque (Nm)Proof Load (N)Max Tightening Torque (Nm)
FU001.4950013.31286017.677108.9
FU012.21108018.91500024.8900012.7
FU023.11781036.72412048.61447024.3
FU033.72018046.92733062.21640031.0
FU044.72902077.839300103.72358050.9
FU059.841160139.455740185.33344091.7
FU0612.749400199.466890265.540130130.6
FU0716.266500309.490050413.354030201.5
FU0819.687080458.4117920613.970750296.9
FU0923.5109720645.6148580865.989150416.6
FU1029.4134580877.21822501177.5109350565.2
FU1135.31451401041.11965401397.3117920670.8
FU1241.21583301238.12144101662.1128640797.6
FU1350.01886801595.22555002142.51533001026.5
FU1454.92031901847.02751602481.81650901187.4
FU1566.62375002310.93216203105.91929701484.9
FU1670.62955603049.84002304104.92401401953.2
FU1776.43364603679.84556204956.02733702353.5
FU1883.33562504123.14824305554.02894502636.2
FU1988.24011104889.45431806590.03259003122.3
FU2096.04486105748.46075007750.53645003668.1

SOCKET TOOLS FOR BEARING LOCKNUTS

Sizes available up to M50.

Quotations/dimensions for larger sockets can be supplied on request.

Order Ref NutDLh1h2s
FU00M10x0.7523364.4249.52 (3.8″)
FU01M12x1.027374.625
FU02M15x1.031385.726
FU03M17x1.034395.827
FU04M20x1.038.5406.928
FU05M25x1.545.546.58.130.512.7 (1/2″)
FU06M30x1.553508.134
FU07M35x1.560.553.59.237.5
FU08M40x1.5675710.241
FU09M45x1.574.560.511.244.5
FU10M50x1.5806412.248
Socket tool material FU00 to FU06 – Japanese steel grade SCM435H FU07 to FU20 – Japanese steel grade SCM440H

AXIAL IMPACT VIBRATION TEST

Test Conditions Machine – NAS high speed screw loosening tester
Sample sizeM20 x 1.0
Frequency21Hz
Excitation stroke11mm
Impact stroke10mm
Vibrating acceleration of excitation table10G
Test time60 minutes
Direction of impactBolt axis direction
Clamping torque53.9N.m (550kgf.cm)
Test Results
Sample NutExcitation Time (Minutes)       10           20            30           40           50          60Test Results
Standard bearing nut with tongued washerLooseness
Δ – x damaged washer (11 minutes) 20o
Nut came off
FUJI Locknut
No effect

Fuji Locknuts Rotational Life Test

Test Conditions
Sample sizeM55 x 2.0
Speed of revolution2,300rpm
Testing cyclesOne cycle (forward rotation, stop, reverse rotation, stop): 10 seconds
Stopping timeOne forward rotation: 0.30 seconds. For reverse rotation: 0.27 seconds
Internal force applied to the nut during stopping
Sample NutInertial Force : N.m (kgf.cm)
For forward rotationFor reverse rotation
Standard Bearing Nut0.14 (1.42)0.15 (1.57)
FUJI Locknut0.15 (1.52)0.17 (1.69)
RESULTS
Sample NutSample NoResult on endurance text
Standard Bearing Nut & Washer1Washer damaged & nut came off at approx. 110,000 cycles
2Washer damaged & nut came off at approx. 330,000 cycles
FUJI Locknut3No change after 500,000 cycles
4
An interesting point to note is the difference in failure times between the two lock washers caused by inconsistent assembly. This is avoided by using the FUJI Locknut.
External view of testing machineExternal view of damaged & detached washers (sample No 2)

BEARING LOCKNUT DIMENSION TABLE

SC SeriesSS SeriesSUS SeriesDesignation of Thread D1D3D4gTShHPerpend-icularity of Bearing Surface
FU00SCFU00SSFU00SUSM10x0.75180-0.513.50-0.514.40-0.51.83+0.245.2+0.30.05
FU01SCFU01SSFU01SUSM12x1.0221718.41.8345.4
FU02SCFU02SSFU02SUSM15x1.0252121.41.8456.5+0.5
FU03SCFU03SSFU03SUSM17x1.0282424.21.9456.4
FU04SCFU04SSFU04SUSM20x1.0322628.41.8467.7
FU05SCFU05SSFU05SUSM25x1.53832342.0579.1
FU06SCFU06SSFU06SUSM30x1.54538412.0579.1+0.8
FU07SCFU07SSFU07SUSM35x1.55244482.05810.2
FU08SCFO08SSFU08SUSM40x1.55850532.56911.2
FU09SCFU09SSFU09SUSM45x1.56556602.561012.5+1.0
FU10SCFU10SSFU10SUSM50x1.57061652.561113.5
FU11SCFU11SSFU11SUSM55x2.07567693.071113.50.07
FU12SCFU12SSFU12SUSM60X2.08073743.071113.5
FU13SCFU13SSFU13SUSM65x2.08579793.071215.0+1.5
FU14SCFU14SSFU14SUSM70x2.09285853.581215.0
FU15SCFU15SSFU15SUSM75x2.09890913.581315.8
FU16SCFU16SSFU16SUSM80x2.010595983.581518.6
FU17SCFU17SSFU17SUSM85x2.01101020-0.751033.58+0.31619.2
FU18SCFU18SSFU18SUSM90x2.01201081124.0101620.3
FU19SCFU19SSFU19SUSM95x2.01251131174.0101721.3
FU20SCFU20SSFU20SUSM100x2.01301201224.0101822.3
FU21SCM105x2.01401261304.0121822.3
FU22SCM110x2.01451331355.0121923.3
FU23SCM115x2.01501371405.0121923.3
FU24SCM120x2.01551381455.0122024.3
FU25SCM125x2.01601481505.0122125.40.10
FU26SCM130x2.01651491555.0122125.4+1.5
FU27SCM135x2.01751601636.0142226.6
FU28SCM140x2.91801601686.0142226.6
FU29SCM145x2.01901711786.0142428.6
FU30SCM150x2.01951711836.0142428.3
NUT THREAD ACCURACY * Dimensions may be subject to change without notice due to our policy of product improvements. ISO6H (JIS Class 2) Unit : mm

Fuji BEARING LOCKNUT MATERIALS

Friction ring – 301 stainless steel
MaterialJISISOBS
SS Low Carbon SteelSS400 (or equivalent)1.004443B
SC High Carbon SteelS45C (or equivalent)1.0503/1.1191/1.1201070M46/080M46/080A47
SUS Stainless SteelSUS304 (or equivalent)1.4301304S31

NOTES ON USE

Fine-U-Nuts are used for fastening critical components.  When using Fine-U-Nut, strict compliance with the following is required:

A lead in chamfer equivalent to one thread pitch is required. The screw thread should be to ISO 965. (Tolerance Class 6g)

Lubricate the shaft before assembly or removal of the nut. With shafts of low hardness use a high performance lubricant.

To maximise effectiveness ensure there are at least two full threads beyond the friction ring.

The squareness specified for the mating face is achieved with a tightening torque equivalent to x2 the prevailing torque – see our literature.

Do NOT use a high rotational speed impact wrench.

Do NOT use the nuts on shafts with keyways.

Do NOT screw in the nut from the friction ring side.

Stop using the nut when excessive deformation or other fault is found in the friction ring and the clamp.

For severe or unusual applications please ask for our advice on 01202 339559.

Get your bearings

Utilise our customised Bearing Selector tool here.

Utilise our customised Bearing Selector tool here.

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