Airframe Control Bearings: Series, Torque and Verification

Series in this line

Click any series concept below. For specific part numbers, dimensions and replacement references, send us your drawing or part number.

Single-Row Standard ⌄

SBO · RBO series

General airframe control applications. Spherical bore or flat bore, sealed or open.

Model	d × D × B (mm)
P4KFS428	6.35×22.352×11.125
P4KFS464	6.35×22.352×11.125
PD5KFS428	7.874×23.876×15.875
PD5KFS464	7.874×23.876×15.875
B5538WZZFS428	15.875×26.988×14.275
B5538WZZFS464	15.875×26.988×14.275
P10KFS428	16.002×30.226×11.125
P10KFS464	16.002×30.226×11.125
B5539WZZFS464	19.05×30.163×14.275
B5540WZZFS428	22.225×33.338×14.275
B5540WZZFS464	22.225×33.338×14.275
B5542WZZFS428	33.338×44.45×14.275

12 models in this series · Request a quote →

Single-Row Precision ⌄

ABEC-5+ · P5+

High-precision controls, instruments and antenna mechanisms. Tighter tolerances on raceway geometry and runout.

Model	d × D × B (mm)
KP16BSFS428	25.4×49.213×11.1
KP16BSFS464	25.4×49.213×11.1
KP21BSFS428	33.35×57.15×11.1
KP21BSFS464	33.35×57.15×11.1
KP23BSFS428	36.525×60.325×11.1
KP23BSFS464	36.525×60.325×11.1
KP25BSFS428	39.7×63.5×11.1
KP25BSFS464	39.7×63.5×11.1
KP29BSFS428	46.05×69.85×11.1
KP29BSFS464	46.05×69.85×11.1
KP33BSFS428	52.4×76.2×11.1
KP33BSFS464	52.4×76.2×11.1
KP37BSFS428	58.75×82.55×11.1
KP37BSFS464	58.75×82.55×11.1
KP47BSFS428	74.625×104.775×13.487
KP47BSFS464	74.625×104.775×13.487
KP48BSFS428	76.2×107.95×13.487
KP48BSFS464	76.2×107.95×13.487
KP49BSFS428	77.788×107.95×13.487
KP49BSFS464	77.788×107.95×13.487

20 models in this series · Request a quote →

Double-Row Standard ⌄

DW series · includes DW4K

Heavier-load control applications. DW4K is the flagship double-row standard type — the most-searched aircraft control bearing. Two rows of balls in back-to-back arrangement handle combined loads in both directions.

DSP size and load comparison →

Cold soak test of aircraft control bearings at minus 55 Celsius — Cold soak verification — bearings tested at −55 °C for low-temperature service

Model	d × D × B (mm)
DPP3FS464	4.826×19.746×12.573
DSP3FS428	4.826×19.746×12.7
DSP3FS464	4.826×19.746×12.7
KP3	4.826×19.746×7.544
KP3A	4.826×15.875×7.544
KP3L	4.826×15.875×6.223
DPP4FS428	6.35×22.896×15.748
DPP4FS464	6.35×22.896×15.748
DPP4WFS464	6.35×22.896×15.748
DSP4FS428	6.35×22.896×17.45
DSP4FS464	6.35×22.896×17.45
DSRP4FS428	6.35×22.86×15.875
DSRP4FS464	6.35×22.86×15.875
DW4	6.35×19.05×22.225
DW4K	6.35×19.05×22.225
DW4K2	6.35×15.875×14.275
DW4K2FS428	6.35×15.875×14.275
DW4K2FS464	6.35×15.875×14.275
DW4KFS428	6.35×19.05×22.225
DW4KFS464	6.35×19.05×22.225
GDW4K2FS428	6.35×15.875×14.275
GDW4KFS428	6.35×19.05×22.225
GDW4KFS464	6.35×19.05×22.225
KP4	6.35×22.896×12.294
KP4A	6.35×19.05×7.137
MDSP4FS428	6.35×22.896×17.45
MDSP4FS464	6.35×22.896×17.45
MDSRP4FS464	6.35×22.86×17.45
MDW4K2FS428	6.35×15.875×14.275
MDW4K2FS464	6.35×15.875×14.275

73 models in this series · Request a quote →

Double-Row Precision ⌄

ABEC-5+ · DW series precision grade

Precision version of the DW double-row type. For critical flight control systems where runout and play must be minimized.

Model	d × D × B (mm)
MKP3AFS428	4.826×15.875×7.544
MKP3AFS464	4.826×15.875×7.544
MKP3ALFS428	4.826×12.7×6.02
MKP3ALFS464	4.826×12.7×6.02
MKSP3FS428	4.826×19.746×7.544
MKSP3LFS428	4.826×15.875×6.223
MKSP3LFS464	4.826×15.875×6.223
MKP4AFS428	6.35×19.05×7.137
MKP4AFS464	6.35×19.05×7.137
MKP4FS428	6.35×22.896×12.294
MKP4FS464	6.35×22.896×12.294
MKSP4AFS428	6.35×19.05×7.137
MKSP4AFS464	6.35×19.05×7.137
MKSP4FS428	6.35×22.896×12.294
MKSP4FS464	6.35×22.896×12.294
MKP5AFS428	7.938×20.638×7.544
MKP5AFS464	7.938×20.638×7.544
MKP5FS428	7.938×31.75×14.173
MKP5FS464	7.938×31.75×14.173
MKSP5AFS428	7.938×20.638×7.544
MKSP5AFS464	7.938×20.638×7.544
MKSP5FS428	7.938×31.75×14.173
MKSP5FS464	7.938×31.75×14.173
MKP6AFS428	9.525×22.225×7.95
MKP6AFS464	9.525×22.225×7.95
MKP6FS428	9.525×36.513×15.748
MKP6FS464	9.525×36.513×15.748
MKSP6AFS428	9.525×22.225×7.95
MKSP6FS428	9.525×36.513×15.748
MKP8AFS428	12.7×28.575×9.525

51 models in this series · Request a quote →

Roller Bearings ⌄

Cylindrical · Tapered · Needle

Landing gear, track and high-shock-load applications where point contact of ball bearings is insufficient. Roller contact handles heavier radial loads.

Model	d × D × B (mm)
KSP3FS428	4.826×19.746×7.544
KSP3FS464	4.826×19.746×7.544
KSP3LFS428	4.826×15.875×6.223
KSP3LFS464	4.826×15.875×6.223
KSP4AFS428	6.35×19.05×7.137
KSP4AFS464	6.35×19.05×7.137
KSP4FS428	6.35×22.896×12.294
KSP4FS464	6.35×22.896×12.294
KSP5AFS428	7.938×20.638×7.544
KSP5AFS464	7.938×20.638×7.544
KSP5FS428	7.938×31.75×14.173
KSP5FS464	7.938×31.75×14.173
KSP6AFS428	9.525×22.225×7.95
KSP6AFS464	9.525×22.225×7.95
KSP6FS428	9.525×36.513×15.748
KSP6FS464	9.525×36.513×15.748
KSP8FS428	12.7×42.863×15.748
KSP8FS464	12.7×42.863×15.748
KSP10FS428	15.875×49.213×20.65
KSP10FS464	15.875×49.213×20.65

20 models in this series · Request a quote →

Radials (6 sub-categories) ⌄

Six sub-categories

Six radial bearing sub-categories: thin-section, groove, instrument, miniature, stainless and special-duty. Interchange is matched by dimensions and function.

Model	d × D × B (mm)
E4	4×16×5
EN4	4×16×5
BB4477	4.064×10.414×6.604
K3L2FS160	4.826×17.526×6.223
K3L3FS160	4.826×16.256×6.223
K3LR48FS160	4.826×17.526×6.223
KP3AFS428	4.826×15.875×7.544
KP3AFS464	4.826×15.875×7.544
KP3ALFS428	4.826×12.7×6.02
KP3ALFS464	4.826×12.7×6.02
KP3FS428	4.826×19.746×7.544
KP3FS464	4.826×19.746×7.544
KP3LFS428	4.826×15.875×6.223
KP3LFS464	4.826×15.875×6.223
PN3A	4.826×12.7×7.544
E5	5×16×5
EN5	5×16×5
E6	6×21×7
EN6	6×21×7
36KLL	6.096×19.05×14.275
H38KDD12	6.35×25.4×10.16
KP4AFS428	6.35×19.05×7.137
KP4AFS464	6.35×19.05×7.137
KP4FS428	6.35×22.896×12.294
KP4FS464	6.35×22.896×12.294
MDPP4FS464	6.35×22.896×15.748
PN4A	6.35×16.002×12.294
E7	7×22×7
EN7	7×22×7
GD5M28FS160	7.874×22.86×23.813

173 models in this series · Request a quote →

DW4K explained

DW4K is NLHB's designation for the double-row standard aircraft control bearing — the most commonly sourced type. It belongs to the DW series (double-row standard), not a separate category. When you see "DW4K" in other catalogues, it maps to our Double-Row Standard series. DW4K2, DW4KX and similar suffixes are precision or variant grades within the same series.

Available options (confirmed per inquiry)

Precision: ABEC-5+ available
Material: Vacuum-degassed steel
Interchange: matched by dimensions and function

Specific configurations are confirmed per quotation. We do not claim every option is in stock for every model — we verify before quoting.

What airframe control bearings do

Airframe control bearings support control linkages and precision oscillating mechanisms. Selection is governed by motion mode, load direction, starting and running torque, construction, corrosion protection, lubricant and documentation. A commercial series name or a dimensional match does not establish aerospace approval or interchangeability. See the airframe control bearing series guide.

Motion mode comes before the catalogue number

Motion: separate oscillation, intermittent rotation and continuous rotation. Many control-bearing families are intended mainly for oscillation or limited rotation.
Torque: define starting and running torque at the required temperature and load.
Documents: material, plating, lubrication, traceability and qualification are controlled requirements.

Series routes

Airframe control catalogues separate standard and precision series, radial and self-aligning arrangements, torque-tube designs, extra-wide double-row products, and full-complement or caged constructions. The series cards above group our catalogue by these routes. A family name describes a design route, not a universal operating envelope.

What we review — and what we do not claim

NLHB reviews drawings, samples and manufacturing feasibility for precision control and oscillatory applications. Any claim of compliance with an aerospace standard, qualification or approved-source requirement must be supported by the exact governing document and customer acceptance; it is not inferred from appearance or designation.

What to send for a review

Drawing or sample and the part number you use.
Motion mode, load direction and required starting and running torque.
Material, plating, lubricant and temperature range.
The governing specification and documentation you need, and the quantity.

Frequently asked questions

Can you supply airframe control bearings to a part number?

We review the drawing, sample and specification behind the part number. A dimensional match alone does not establish interchangeability or approval.

Are your bearings aerospace qualified?

Qualification or approved-source status must be supported by the exact governing document and customer acceptance. We do not claim it from appearance or designation.

What matters most when selecting a control bearing?

Motion mode, load direction and starting and running torque, then construction, corrosion protection, lubricant and documentation.

What should I send for a review?

A drawing or sample, the part number, motion mode, load, torque, material, plating, lubricant, temperature, the governing specification and the quantity.

Aircraft Bearings