Advanced Product Solutions

Four-Row Tapered
Roller Bearings

Four-row tapered roller bearings are designed specifically to support the work rolls of rolling mill stands. As their purpose suggests, they are engineered to withstand heavy and impact loads transmitted – radially and axially – as steel passes through rolling stands and is reduced in thickness by the work rolls. They must also accommodate wide speed variations with rapid acceleration and deceleration.

Equally challenging to these bearings is the environment: not only high temperatures but mill scale contamination and water penetration as well. NSK four-row tapered roller bearings are available with long-life Super-TF steel to deliver superior durability and wear resistance. For aggressive environments, NSK’s Sealed-Clean design offers improved heat- and water-resistant sealing protection, promoting reduced grease consumption and maintenance costs.

Proven Benefits

Higher reliability and longer operating life with Super-TF steel, reducing bearing replacement and maintenance intervals
Sealed-Clean solution extends bearing performance, promotes a cleaner work environment and significantly reduces grease consumption
Advanced AQGRD grease for sealed-type bearings provides optimal water-resistance, preventing grease deterioration and bearing damage

Design Features

Special design high load capacity four-row tapered roller bearing
With long-life Super-TF steel for dramatically longer service life under contaminated operating conditions
With machined steel window- and pin-type cages
Spiral groove on the inner ring bore to prevent creeping wear on the roll neck shaft
Available as open or advanced heat- and water-resistant sealed-type bearings
Sealed version available with long-life AQGRD R1 water-resistant grease
Corrosion resistant phosphate option for inner ring
With special radial and axial internal clearances
Available in inch and metric design types

Designation System (Sealed Type)

Bearing Dimensions and Operating Values (Sealed Type)

STF170KVS2401Eg 170 240 175 175 2.5 2.5  1 020  2 010 0.32 3.2 2.1
STF215KVS2851Eg 215.9 288.925 177.8 177.8 3.3 0.8  1 070  2 350 0.49 2.1 1.4
STF216KVS3351Eg 216.103 330.2 263.525 269.875 3.3 1.5  2 290  4 550 0.46 2.2 1.5
STF220KVS3301Eg 220 330 260 260 3.0 4.0  2 330  4 800 0.40 2.5 1.7
STF220KVS3151Eg 220.662 314.325 239.712 239.712 3.3 1.5  1 960  4 350 0.33 3.0 2.0
STF228KVS3151Eg 228.6 311.15 200.025 200.025 3.3 1.5  1 560  3 500 0.33 3.0 2.0
STF234KVS3251Eg 234.95 327.025 196.85 196.85 3.3 1.5  1 550  3 200 0.46 2.2 1.5
STF241KVS3451Eg 241.478 349.148 228.6 228.6 3.3 1.5  2 020  4 150 0.35 2.9 1.9
STF244KVS3251Eg 244.475 327.025 193.68 193.68 3.0 1.5  1 370  3 050 0.40 2.5 1.7
STF245KVS3402Eg 245 345 310 310 3.0 2.0  2 700  6 650 0.40 2.5 1.7
STF254KVS3552Eg 254 358.775 269.875 269.875 3.3 1.5  2 420  5 500 0.40 2.5 1.7
STF260KVS3601Eg 260 365 340 340 4.0 2.7  2 960  7 350 0.40 2.5 1.7
STF260KVS3651Eg 365 340 340 4.0 2.5  2 960  7 350 0.40 2.5 1.7
STF260KVS4251Eg 260.35 422.275 314.325 317.5 3.3 6.4  3 600  7 050 0.33 3.0 2.0
STF266KVS3551Eg 266.7 355.6 230.188 228.6 3.3 1.5  1 960  4 600 0.35 2.9 1.9
STF275KVS3801Eg 275 380 340 340 3.0 3.0  3 100  7 750 0.32 3.2 2.1
STF276KVS3952Eg 276.225 393.7 269.875 269.875 3.3 1.5  2 720  6 100 0.45 2.2 1.5
STF279KVS3952Eg 279.4 393.7 269.875 269.875 6.4 1.5  2 720  6 100 0.45 2.2 1.5
STF279KVS3954Eg 393.7 320 320 6.4 1.5  3 100  7 350 0.40 2.5 1.7
STF280KVS3801Eg 280 380 290 290 3.0 3.0  2 690  6 500 0.33 3.0 2.0
STF280KVS3804Eg 380 340 340 4.0 1.5  2 870  7 650 0.33 3.0 2.0
STF280KVS4301Eg 430 350 350 3.5 2.0  4 100  8 558 0.40 2.5 1.7
STF290KVS4001Eg 290 400 346 346 4.0 3.0  3 250  8 400 0.40 2.5 1.7
STF304KVS4351Eg 304.648 438.048 280.99 279.4 3.3 3.3  3 100  6 750 0.45 2.2 1.5
STF304KVS4155Eg 304.8 419.1 269.875 269.875 6.4 1.5  2 850  6 550 0.33 3.0 2.0
STF304KVS4152Eg 304.902 412.648 266.7 266.7 3.3 1.5  2 760  6 500 0.33 3.0 2.0
STF310KVS4301Eg 310 430 310 310 3.0 3.0  3 350  8 200 0.46 2.2 1.5
STF310KVS4302Eg 430 350 350 3.0 2.7  3 700  9 550 0.46 2.2 1.5
STF317KVS4251Eg 317.5 422.275 269.875 269.875 3.3 1.5  2 740  6 750 0.34 3.0 2.0
STF317KVS4451Eg 447.675 367 367 3.0 3.6  3 850  9 500 0.33 3.0 2.0
STF343KVS4551Eg 340.052 457.098 254 254 3.3 1.5  2 830  6 700 0.45 2.2 1.5
STF355KVS4551Eg 355.6 457.2 252.412 252.412 3.3 1.5  2 650  6 750 0.32 3.2 2.1
STF355KVS4851Eg 482.6 265.112 269.875 3.3 1.5  3 100  7 200 0.47 2.1 1.4
STF374KVS5051Eg 374.65 501.65 250.825 260.35 3.3 1.0  2 970  7 150 0.47 2.1 1.4
STF384KVS5451Eg 384.175 546.1 400.05 400.05 6.4 3.3  5 250  12 400 0.33 3.1 2.1
STF385KVS5151Eg 385.762 514.35 317.5 317.5 3.3 3.3  4 150  10 400 0.33 3.0 2.0
STF390KVS5101Eg 390 510 350 350 3.0 1.5  3 900  10 800 0.35 2.9 1.9
STF406KVS5451Eg 406.4 546.1 288.925 288.925 6.4 1.5  3 950  9 450 0.48 2.1 1.4
STF406KVS5452Eg 546.1 330 330 6.4 1.0  4 350  11 000 0.48 2.1 1.4
STF406KVS5651Eg 562 381 381 6.4 3.3  4 950  11 900 0.33 3.0 2.0
STF409KVS5451Eg 409.575 546.1 334.962 334.962 6.4 1.5  4 500  11 700 0.40 2.5 1.7
STF450KVS5901Eg 450 595 368 368 5.0 4.0  5 550  15 000 0.33 3.0 2.0
STF457KVS5951Eg 457.2 596.9 276.225 279.4 3.3 1.5  4 000  9 850 0.47 2.2 1.4
STF482KVS6151Eg 482.6 615.95 330.2 330.2 6.4 4.3  4 900  13 500 0.33 3.1 2.1
STF489KVS6351Eg 489.026 634.873 320.675 320.675 3.3 3.3  4 850  12 500 0.38 2.7 1.8
STF490KVS6201Eg 490 625 385 385 3.0 3.0  5 650  16 600 0.32 3.2 2.1
STF558KVS7353Eg 558.8 736.6 455.6 457.2 6.4 3.3  8 300  23 000 0.35 2.9 2.0
STF585KVS7751Eg 585.788 711.525 479.425 479.425 6.4 3.0  8 250  22 700 0.33 3.0 2.0
STF660KVS8151Eg 660.4 812.8 365.125 365.125 6.4 3.3  6 050  17 700 0.33 3.0 2.0
STF708KVS9351Eg 708.025 930.275 565.15 565.15 6.4 3.3  12 000  34 000 0.33 3.0 2.0

Extra-Capacity Sealed-Clean Four-Row Tapered Roller Bearings are made of NSK Super-TF material as the standard specification

Bearings marked ● are inch design.

Additional bearing designs / sizes are available. Please contact NSK for additional information.