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Inner ring and roller set for a double-row cylindrical roller bearing, 105 mm tapered bore (1:12), 41 mm wide, machined brass cages, P4 super-precision, C1 clearance. Supplied without the outer ring. 1 Pc.
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| MFR / Brand | NTN |
|---|---|
| MPN | NN3021KC1NAP4 |
| Model | NN 3021 K C1 NA P4 |
| Bearing Type | Cylindrical Roller Bearing, Open |
| ID | 105 mm |
| OD | 160 mm |
| Width | 41 mm |
| Material | Bearing Steel |
|---|---|
| Series | NN 30 |
| Condition | New – Open box |
| Bore | Taper Bore |
| Base Number | NN3021 |
| Industry Terms | double row cylindrical roller bearing, inner ring and roller set, tapered bore spindle bearing, machine tool spindle roller bearing, super precision cylindrical roller, NN series bearing |
| Common Misspellings | NN3021 K C-1 NA P4, NN 3021KC1NAP-4, NTN NN3021KCINAP4, cylindrical rollor bearing, cylinderical roller bearing |
| Application Types | Machine tool spindles, grinding and boring spindles, precision gearboxes, rotary tables |
| Condition Note | Made In Japan, New Old Stock, No Outer Race |
| Bore Shaft Size | 105 mm (1:12 tapered bore, mounts direct on a tapered journal) |
| Mpn Variants | NN3021KC1NAP4, NN3021-K-C1-NA-P4, NN 3021 K C1 NA P4, NN3021KC1P4, NN3021KP4, NN3021K, NN3021, NN-3021 |
| Compatible With Replaces | ISO NN3021 K double-row cylindrical roller envelope, 105 x 160 x 41 mm, tapered bore, super-precision class |
| Arrangement Configuration | Inner ring and roller set only, no outer ring. Radial load only, no axial location. |
| Precision Class | P4 / ISO class 4 |
| Min Temp | -40°C |
| Cage Type | Machined |
| Dynamic Load Rating | 159 kN |
| Static Load Rating | 269 kN |
| Precision Rating | ABEC 7 / P4 |
| Rolling Elements | Cylindrical |
| Max Temp | 120°C |
| Item Weight | 5.84 lbs |
| Cage Material | Brass |
| Number Of Rows | 2 |
| Bore Type | Tapered 1:12 (K) |
| Snap Ring Included | Without Snap Ring |
| Harmonization Code | 8482.50.00.00 |
| Design Units | Metric |
| Bearing Material | Bearing Steel |
| Internal Clearance | C1 |
| Part Number | NN3021-K-C1-NA-P4 |
| Cross Reference 1 | SKF NN 3021 K/SP |
|---|---|
| Cross Reference 2 | FAG NN3021-AS-K-M-SP |
| Cross Reference 3 | NSK NN3021TBKRE44CC1P4 |
| Cross Reference 4 | NA (NTN suffix, searchable designation) |
The inner ring and roller assembly of an NTN NN3021-K-C1-NA-P4 double-row cylindrical roller bearing. Tapered bore 105 mm on a 1:12 taper, 41 mm wide, two rows of cylindrical rollers retained by machined brass cages between the integral ribs of the inner ring, built to P4 super-precision. Supplied without the outer ring.
NN marks the double-row cylindrical roller family; 30 is the dimension series and bore code 21 gives 105 mm. K is the 1:12 tapered bore. C1 is the extra-tight clearance grade used on machine-tool spindles. P4 is ISO class 4, equivalent to ABEC 7. The complete bearing measures 105 x 160 x 41 mm.
Inner ring and roller set only, 1 Pc. Supplied without the outer ring. On an NN the ribs that guide and retain the rollers are machined into the inner ring, so the roller complement stays captive on this half and the outer ring is a plain cylindrical sleeve.
A K bore on an NN mounts directly on a matching 1:12 tapered spindle journal. No adapter sleeve, withdrawal sleeve or locknut assembly forms part of the mounting, which is the opposite of a K bore on a spherical roller bearing. Drive-up on the taper expands the inner ring, and that expansion is how radial internal clearance is set on assembly.
Two rows of line-contact rollers give very high radial stiffness and radial load capacity for the section, and the design carries radial load only, with axial location taken by a separate bearing. P4 accuracy and a taper-set clearance are what let a spindle hold low radial runout at speed, and the tapered mount allows clearance to be adjusted at build rather than fixed by the shaft fit.
The complete-bearing equivalents in this envelope are SKF NN 3021 K/SP, FAG NN3021-AS-K-M-SP and NSK NN3021TBKRE44CC1P4. Clearance grade, precision class and bore form are all part of the identity, so a straight-bore NN3021 or a looser clearance grade is a related size. The mating outer ring is a matched component of one specific bearing rather than a catalogue-interchangeable part.
$266.00
6 in stock
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