Precautions for purchasing four row cylindrical roller bearings-NEWS-www.fv-bearing.com

Precautions for purchasing four row cylindrical roller bearings

Aug 30, 2021


This is the first article in the "Kevin Words Bearing" column.  Mr Kevin will continue to update valuable experience every week and share them with you. 

KEVIN SAID BEARINGS

Four row cylindrical roller bearing is the most popular high-speed bar mill bearing in the world. But it is true that steel mills encounter many strange troubles in the procurement process. Our application engineers maintain long-term communication with users. Now summarize the following precautions to customers and give our solutions.

1. Application and material selection:

At present, small and medium-sized four row cylindrical roller bearings are most widely used in the field of long mill, and the inner diameter of the bearing is usually ≤ 340mm in China. The raw materials of this type of bearing are GCr15, GCr15SiMn and a small amount of GCr18Mo. The heat treatment of bearing parts is usually martensite hardening, bainite hardening and composite hardening. The hardness of the bearing is usually HRC 59-62. The four row cylindrical roller bearing made of this material and heat treatment process can be well used in hot-rolled bar and threaded steel mills. The price is very good.

Quality difference points: 1. Purity and oxygen content of steel    2. Heat treatment quality, conversion rate of martensite and bainite     3. Cage Quality 


Solution: confirm the raw material certificate, heat treatment certificate and hardness test report


2. Manufacturing accuracy of bearing

The bearing used in high-speed long strip mill usually has better rotation and dimensional accuracy than p6. Better rotation accuracy can improve the service life of the bearing and the quality of rolled steel bar. High precision bearings play a positive role in the reliability of the whole rolling mill system. However, the market is full of rolling mill bearings with accuracy lower than P6, P0 grade bearings and poor quality bearings.


Quality difference points: 1. Overall dimension accuracy      2. Rotation runout accuracy    3. (Rollers Quality *)


Solution: our engineers suggest to buy rolling mill bearings with accuracy better than p6.  Although the price is slightly more expensive, it has a longer working life. More competitive.


3. Internal clearance and interchangeability of bearing

The most special property of four row cylindrical mill bearings is their interchangeability. In the process of rolling steel, workers need to change rolls regularly. The inner ring of the bearing needs to be replaced together with the mill roll. This is a problem that breaks out frequently. The inner ring and outer ring components of four row cylindrical roller bearings can be separated. And the internal clearance is determined by the parts together. Please refer to the figure below, and I will give you an example (Model: 313812 C4 fou-row cylindrical roller bearing), which will help us understand the important line of this problem.  

four row cylindrical roller bearing 313812 drawing

International general standards:   Fw=202 (+0.025, 0) ; Raceway diameter of inner ring = 202 (-0.170 , -0.195)  Then the internail radial clearance 0.170 ~ 0.220mm    RIC=C4;

Some unknown brands have their own standards:   Fw=202 (+0.110, +0.085) ;  Raceway diameter of inner ring =  202 (-0.085, -0.110). Then the internail radial clearance also  0.170 ~ 0.220mm  RIC=C4 also;

If the user purchases bearings of different standards, there will be bad trouble: 
Case 1:   202 (+0.025, 0)   &   202 (-0.085, -0.110),  then the RIC= 0.085 ~ 0.135 mm   RIC=CN,  this clearance is too small.  

Case 1:   202 (+0.110, +0.085)   &   202 (-0.170, -0.195),  then the RIC= 0.255 ~ 0.305 mm   RIC=C5,  this clearance is larger than C4. 

Both cases may reduce the working life of the rolling mill bearing,  We need attention and control.


International standard for Inner Ring Interchange:

FV ROLLING MILL BEARINGS INNER RING FOR BAR MILL


Difference: it is not necessary to follow the interchange tolerance of ISO standard. Different manufacturers may have different standards.


Solution: strictly confirm the drawings before purchasing. The inner ring raceway diameter tolerance and the outer ring roller lower end diameter tolerance shall be confirmed. Confirm that it meets the exchange standard of the bearing currently in use before determining the purchase.


4. Bearing design details


There are many manufacturers of rolling mills or rolling mill bearing housings in the world. The lubrication system of the bearing housing must match the bearing. The number, position and size of lubrication holes or grooves on the bearing outer ring or inner ring shall be correct. At present, whether the outer diameter and four end faces of small four row cylindrical roller bearings need lubrication grooves. This will affect the service life of the bearing.

four row cylindrical roller bearing drawing

Does the cage material and interior of the bearing need improved design? Generally, the most common is the turning solid copper / steel cage. At present, there will be some upgraded designs on the market to change the diameter, length and quantity of internal rollers. The bearing can be added with a certain load rating, such as the solid window cage design. Improved design does not necessarily apply to all users. The customer needs to try before deciding.

Difference:  whether there is correct lubrication / disassembly lubrication groove. Is it in line with the original design?


Solution: the mechanical maintenance engineer shall carefully check the original drawings and the design of the bearing housing. Ensure that grease can be smoothly injected into the bearing. Ensure that the maintenance engineer needs these lubrication grooves.


5. Professional suppliers and manufacturers

There are thousands of bearing brands in the world. There are more than tens of thousands of bearing models. Not every bearing brand focuses on rolling mill bearings. Rolling mill bearings are only a small series in the bearing family. Many bearing brands do not understand the application of bearings. They don't understand the above 1-4 problems. These bearing brands may not know more about these rolling mill bearings than customers. Do not ask the price before purchasing all rolling mill bearings. Please be sure to ask the supplier if they know about rolling mill bearings.  Does the supplier have its own professional rolling mill bearing catalgue and samples.  I believe users should ask some professional questions to test the professional ability of bearing suppliers. 


Difference: is it a professional rolling mill bearing supplier


Solution: it is recommended that steel mill users contact China FV bearing company, or SKF, Timken and other international brands. Because FV not only supplies bearings, but also helps users solve many difficult problems in the production process. FV is a knowledge-based industrial bearing brand.

FV have shown bearing model list of wire rod mill that FV can supply.     Please collect and share. 

Four row cylindrical roller bearings for Wire,bar long production rolling mill

CHINABoundary dimensionOther brands replaced
ModeldDBFwSKFFAGNSKNTNKOYO
FC16231088011510890
FC1828709014070105
672718
FC1828749014074105
FC182810590140105105
672718K
FC20278010013580110
FC20287010014070111
FC20288010014080111
FC2028104100140104111
100RV1401
FC20297010014570113
20FC1570
FC2030106100150106113
FC22349011017090127
22FC1790
FC2234120110170120127
110RV1701
FC24369211018092137
4R2437
FC2436105110180105135
4R24384CR120
FC2640104130200104150
4R262826FC20104
FC2640125130200125149
130RV2001
26FC20125
FC2838119140190119154
4R283228FC19119W
FC28428014021080156
FC2842106140210106158
FC2842125140210125158
FC2842155140210155158
FC2942155145210155166314625511605145RV21014R290629FC21155
FC2945156145225156169313924A538522145RV22014R2904313924
FC3040120150200120162
30FC20120
FC3042120150210120166
FCD3042120150210120166
FCD3042120150210120168.5
30FC21120
FC3042150150210150165
30FC21150
FC3044120150220120167
FC3044127150220127168
4R3036
FC3044150150220150170
4R303130FC22150
FC3044150A150220150168
150RV22014R305630FC22150A
FCD3045112150225112170
FC3045120150225120169
FCD3045120150225120169
FC3045150150225150169
FC3045150A150225150168.5
150RV2203
FC3045136150225136168.8
150RV2204
FC3046130150230130174
150RV23014R3029
FC3046156150230156174313891A506962150RV23024R3040313891-1
FC3046168150230168178
4R3042
FC3050120150250120178
FC3050150150250150177
4R3039
FC3244180160220180177
4R322432FC22180
FC3246130160230130180314190502894
4R3226314190
FC3246130A160230130178
160RV2301
FC3246168160230168179315189A510150B
4R323232FC23170B
FC3246168A160230168180
160RV23024R322932FC23170A
FC3246168A1160230168182
4R323132FC23170
FC3246180160230180177
4R322832FC23180A
FC3246180A160230180178
160RV2303
FC3248120160240120183
160RV2401
32FC24120W
FC3248124160240124183
FC3248145160240145180
160RV2403
FC3248168160240168183
FCD3248168160240168183
FC3248170160240170183
160RV24024R322532FC24170
FC3446120170230120187
170RV23014R3426/4R344334FC23120
FC3446130170230130188.5313673508370
FCD3446160170230160185.5
567622
FC3446180170230180186
FC3448130170240130190BC4B635122510440B
FC3448156170240156189
4R342934FC24156B
FC3448156A170240156190
34FC24156A
FC3448160170240160190
170RV24024R3423
FC3448190170240190187
34FC24190
FC3450168170250168192
170RV2501
34FC25168
FC3450168A170250168193
4R3432/4R3428
FC3450170170250170192
170RV2502
34FC25170
FC3451180170255180193
170RV25034R3425
FC3452120170260120195
FC3452150170260150195
170RV2602
34FC26150
FC3452150A170260150192
4R3433
FC3452170170260170195
FC3452225170260225196313587B505470
4R3431
FCD3650100180250100200
FC3650120180250120200
FC3650156180250156200
180RV25014R362536FC25156A
FC3650168180250168202
180RV26014R363936FC26168
FC3652120180260120202
FC3652124180260124202
FC3652168180260168202313812507536180RV26014R3628313812W
FCD3652168180260168202
FC3653180180265180204
180RV26024R3618
FC3653180A180265180203
180RV2603
36FC27180
FC3656180180280180206
524372
FC3645180A180280180205.1
180RV2802
FC3852124190260124212
FC3852124A190260124208
FC3852168190260168212313651507735190RV26014R382038FC26168-1
FC3852168A190260168208
FC3853124190265124213
FC3854168190270168212
FC3854170190270170212
190RV2703
38FC27170
FC3854170A190270170213
190RV27024R381838FC27170A
FC3854200190270200212314199B508657190RV27014R3821/4R3817314199
FC3856200190280200214314049A510199190RV28014R3823/4R383038FC28200
FC3856200A190280200222313583
FC3858190190290190215
38FC29190
FC4050200200250200215
200RV2521
FC4054170200270170222314553522742B
4R4039314553
FC4056152200280152222
4R405440FC28152BW
FC4056170200280170222314385507344
4R404840FC28170
FC4056170A200280170223
549864200RV2804
FC4056188200280188222
40FC28188
FC4056190200280190223
200RV2803
4R402640FC28190A
FC4056200200280200222313893508726200RV28024R4037313893-1
FC4056200A200280200224
200RV28014R402740FC28200
FC4058130200290130226
FC4058192200290192226313811512580B200RV29014R4041313811
FCD4058192200290192226
FC4062160200310160232
40FC31160
FC4062206200310206227
40FC31206
FCD4062230200310230229
503901.N12BA200RV3102
FCD4062265200310265227
514958
FC4064216200320216231
200RV3231
FC4258192210290192234313646
FC4258192A210290192236
507628210RV29014R420642FC29192
FC4260170210300170234
FC4260210210300210234
42FC30210
FCD4260210210300210234
FC4458192220290192239
4R4413
FC4460150220300150240
44FC30150W
FC4460160220300160245
4R4419/4R4445
FC4460192220300192242
FCD4460200220300200240
567623
FC4462192220310192246313839507333
4R4426313837A
FC4462192A220310192247
220RV31014R4410313837-1
FC4462192A1220310192245
44FC31192W
FC4462204220310204247
4R4425
FC4462215220310215242
4R4420
FC4462225220310225245
506869220RV31024R4416
FC4462225A220310225246
FC4462225A1220310225244313894B514461
4R444944FC31225A
FC4464160220320160245
4R4428
FC4464210220320210248
509216220RV32014R442944FC32210-1
FC4464210A220320210246
220RV32034R444444FC32210
FC4466230220330230249314889541452
FC4468180220340180256
44FC34180A
FCD4468290220340290250
525147
FC4666170230330170260
FC4666206230330206260313824508727B230RV33014R4610313824A
FC4666206A230330206258
4R4614
FC4668260230340260261
230RV34014R461146FC34260
FCD4668260230340260261
FC4673250230365250266313581A529113230RV3601
FC4866180240330180265
504547
FC4866220240330220264
4R481948FC33220
FCD4866220240330220264
FC4866220A240330220268
4R482148FC33220BW
FC4866220A1240330220270313921508368240RV33014R4811/4R4804312943/1YD
FC4866250240330250263
48FC33250W
FC4868192240340192266
FC4868200240340200266
512972
48FC34200
FC4868220240340220268
513703240RV34034R480648FC34220
FCD4870220240350220270
FC4872220240360220272
240RV3601
FC4872220A240360220274
4R4807/4R4813
FCD4872290240360290270
514959
FC5068170250340170274
FCD5068220250340220274
FC5068230250340230276
522310
FC5070220250350220278
250RV35014R500850FC35220
FCD5070220250350220278
FC5072220250360220282
FCD5271260260355260286
260RV3521
52FC35260
FC5272192260360192288
FC5272192A260360192287
52FC36192W
FC5272200260360200287
52FC36200
FC5272220260360220292
4R5521
FC5272200260360200288
FC5272230260360230292.2
533880
FC5272230A260360230292.5
52FC36230CW
FC5272230A1260360230292
52FC36230D
FC5272260260360260287
4R5231
FCD5272260260360260287
52FC36260
FC5274200260370200292
FC5274220260370220292313823507336260RV37014R5217/4R5208313823
FC8274220A260370220290
313823A
FC5274230260370230292
FC5274260260370260290
52FC37260
FC5276220260380220292
FC5276280260380280294
260RV38014R5213
FCD5276280260380280294
FC5280290260400290296
260RV4001
FCD5280290260400290296313427518214
4R5218
FCD5280335260400335294
521065
FC5476230270380230298
270RV3801
54FC38230
FC5476280270380280297
4R5407
FCD5476280270380280299.7
4R5405
FC5476275270380275298
FC5478220270390220306
54FC39220
FC5478240270390240298
FC5670208280350208298
4R5614
FC5675200280375200307
FC5676170280380170306
56FC38170W
FC5676192280380192310
56FC38192
FCD5676290280380290308
FC5678220280390220312313822507339B280RV39014R5611/4R5604313822/313822D
FCD5678220280390220312
FC5678220A280390220308
313822A
FC5678220A1280390220306
313822C
FC5678240280390240312
280RV3902
56FC39240
FC5678275280390275312
513729A
4R5612
FCD5678275280390275308314719C527104
56FC39275J
FC5678275A280390275308
280RV3903
FC5678275A1280390275309
56FC39275B
FCD5680285280400285316
513342.N12BA280RV4021
FCD5682300280410300313
510350.C4.N12BA
FCD5684280280420280318
FC5684280A280420280323
4R5605
FC5878234290390234320
290RV3901
58FC39234
FC5880180290400180320
58FC40180W
FC5882240290410240320
290RV41014R580658FC41240
FCD5882240290410240320
FC5884300290420300327
290RV42014R580558FC42300
FC5888310290440310328
517796
FC6080300300400300328
300RV40214R601460FC40300A
FC6084218300420218332
60FC42218
FC6084240300420240332
300RV42014R602760FC42240
FC6084240A300420240334
4R6012/4R6017
FC6084240A1300420240336
4R6023
FCD6084240300420240332
FC6084300A300420300334
4R6015
FCD6084300300420300332314484D524289B300RV42214R602060FC42300W
FCD6084300A300420300331
4R603060FC42300DW
FCD6084320300420320332
4R6018
FC6086240300430240338
4R6021
FC6092270300460270344
4R6019
FCD6092350300460350341
517795
FC6284300310420300338
310RV4201
62FC42300
FC6286240310430240344.5
310RV43014R620262FC43240
FC6288240310440240345
574469
FC6288240A310440240341
62FC44240
FC6488230320440230351
64FC44230/240
FC6488240320440240351
4R6414
FCD6488240320440240351
FCD6488300320440300352
FC6490240320450240355
320RV4502
64FC45240
FCD6490240320450240355
FC6490240A320450240358
320RV45014R64114CR320/64FC45240CW
FC6492240320460240364
804571
FCD6492300320460300357
FC6492340320460340360
4R641264FC46340A
FCD6492340320460340360
FCD6494350320470350361.7
4R6406
FCD6496290320480290364
FCD6496290A320480290361
64FC48290
FCD6496350320480350364314274B541851320RV4811
341274A
FC6686230330430230358
330RV4301
FC6688200330440200360
330RV44014R6603/4R660866FC44200W
FC6688200A330440200358
66FC44200AW
FC6692340330460340365
330RV46014R6605
FCD6692340330460340365313445C543447
FC6692340A330460340368
4R660266FC46340B
FC6692340A1330460340364
66FC46340
FC6692380330460380364
66FC46380W
FC6889250340445250367
68FC45250W
FC6890250340450250364
FCD6890250A340450250369
FC6890250A1340450250371
340RV4501
FCD6890250A1340450250371
FC6890250A2340450250366
FC6890250A3340450250368
340RV4502
68FC45250BW
FCD6892260340460260370
FCD6896280340480280374
340RV4801
FCD6896350340480350378314485C527634340RV4812E4R681968FC48350-2
FCD6896350A340480350376
68FC48350L
FC6896370340480370378
4R6811
FCD6896385340480385378
68FC48350N
FC6898300340490300377
4R6804
FC6898300A340490300380
4R680568FC49300
FC6898300A1340490300379
68FC49300A
FCD68100370340500370385
517794
FCD68112380340560380396
545171
FCD70100380350500380389314563532381.N12BA
FCD70100410350500410388
532001
FCD70100460350500460388
70FC50460
FCD70104300350520300401BC2B319878568450
FC7296290360480290388
4R7207
FC7296290A360480290394
360RV4801
FC7296290A1360480290392
72FC48290
FCD72100250360500250394BC2B320075
72FC50250
FC72102370360510370400
360RV51014R721272FC51370
FCD72102370A360510370397
FCD72102380360510380399316890B
FC72102400360510400397
4R7203
FCD72102400360510400399
4R7205
FCD72104380360520380405314486A562913
72FC52380
FC7496230370480230400
4R7405
FC7496250370480250401
370RV48014R7408
FC74104380370520380409
370RV52114R7411
FCD74104380370520380409
543975
74FC52380
FC74104400370520400409
4R7404
FCD74104400370520400413
74FC52400W
FC74108400370540400415
370RV5401
74FC54400A
FC76100290380500290414
380RV5001
FC76104280380520280417
380RV52024R760576FC52280
FC76104290380520290418
576360380RV5201
76FC52290
FC76104290A380520290417
4R7617
FC76104300380520300416
4R7607
FCD76108300380540300421
541982
76FC54300
FC76108340380540340424
380RV5431
FCD76108340380540340422
76FC54340W
FCD76108360380540360422
76FC54360
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4R7604
FCD76108400380540400422
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FC76108400380540400424
380RV54014R7613
FC78102290390510290424
390RV5101
FCD78108320390540320431
578278
FCD78110400390550400434
390RV5521
78FC55400AW
FC80104250400520250432
400RV5202
80FC52250W
FC80110300400550300441
400RV5501
FCD80112360400560360441
80FC56360
FC80112400400560400446
400RV56214R8007
FCD80112400400560400446
400RV5612
FCD80112410400560410445
513769A400RV56114R801080FC56410
FC80118420400590420450
4R8011
FCD80118440400590440450
542395
FCD80120380400600380450
80FC60380
FCD82112400410560400450
543736
FCD82120440410600440460
517436410RV6011
82FC60440
FC84112280420560280457
420RV56014R840384FC56280
FCD84112400420560400458
420RV5602
84FC56400
FC84116230420580230466
4R8404
FCD84116320420580320463
533053.N12BA
86FC58320
FCD84120440420600440469.6
4R8407
FCD84120440A420600440470
565467420RV6011
4CR420A


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