spacer spacer spacer spacer
Kaydon Bearings spacer spacer


customer service


Kaydon slewing bearings

Glossary of abbreviations and symbols

Bearing & gear dimensions
Symbol Feature Units
α Pressure angle of gear teeth °
b2 Face width of gear teeth in
Bi Size of hole in inner ring in
Bo Size of hole in outer ring in
D2 Pitch diameter of gear in
di Inside diameter of inner ring in
Di Internal diameter on outer ring in
Do Outside diameter of outer ring in
do External diameter on inner ring in
Dp Diameter of bearing raceway in
dr Internal diameter on inner ring in
Dr External diameter on outer ring in
Dw Diameter of rolling element in
FD Full depth involute spur gear
(ref. ANSI B6.1-1968, R1974 or ISO 53:1998)
FS Fellows stub involute spur gear
(ref. Machinery's Handbook, 18th Edition)
H Height of overall bearing assembly in
Hi Height of inner ring in
Ho Height of outer ring in
Li Bolt circle in inner ring in
Lo Bolt circle in outer ring in
m Module of gear teeth = 25.4/Pd mm
nf Number of lubrication
nipples/fittings per plane
ni Number holes in inner ring -
no Number holes in outer ring -
Pd Diametral pitch -
SD Stub involute spur gear
(ref. ASA B6.1-1932)
x2 Addendum modification coefficient of gear teeth
("+" sign increases tooth thickness at D2
and "-" sign decreases tooth thickness at D2)
z2 Number of gear teeth -

Bearing & gear properties
Symbol Feature Units
Crm Moment load rating ft-lbs
Fz Maximum allowable gear tooth load lbs
G Weight of bearing assembly lbs
Mw Friction torque of bearing,
installed and subjected to loads

Pinion dimensions
Symbol Feature Units
b1 Face width in
D1 Pitch diameter in
Di1 Stock bore in
Do1 Outside diameter in
Dr1 Diameter of hub in
L1 Length of pinion in
Pd Diametral pitch -
w Square key size, nominal in
x1 Addendum modification coefficient -
z1 Number of teeth -

Application data
Symbol Feature Units
fa Application Service Factor -
Fa Force parallel to bearing axis of rotation lbs
Fr Force perpendicular to bearing axis of rotation lbs
Mk Tilting moment about bearing centerline ft-lbs
N Rotational speed rpm
μ Friction coefficient -

Symbol Feature Units
ft Linear unit of measurement foot
ft-lbs Units of torque or moment foot-pounds
in Linear unit of measurement inch
lbs Units of force or weight pounds
mm Linear unit of measurement (SI) millimeter
spacer Warning -

AGMA American Gear Manufacturers Association
ANSI American National Standards Institute
ASTM American Society for Testing and Materials
DIN Deutsches Institut für Normung
ISO International Standards Organization
NLGI National Lubricating Grease Institute
SAE Society of Automotive Engineers


Log in to access 3D models,
CAD files, and engineering software
Forgot password?  |  Register



Bearing & gear dimensions
Bearing & gear properties
Pinion dimensions
Application data