MacDon FD75 OM - Manual (Page 36)

REFERENCE
Term Definition
NPT
National Pipe Thread: a style of fitting used for low pressure port openings. Threads
on NPT fittings are uniquely tapered for an interference fit.
ORB
O-ring boss: a style of fitting commonly used in port opening on manifolds, pumps
and motors.
ORFS
O-ring face seal: a style of fitting commonly used for connecting hoses and tubes.
This style of fitting is also commonly called ORS, which stands for O-ring seal.
PTO Power Take-Off.
RoHS (Reduction of
Hazardous Substances) A directive by the European Union to restrict the use of certain hazardous
substances (such as hexavalent chromium used in some yellow zinc platings).
SAE Society Of Automotive Engineers.
Screw
A headed and externally threaded fastener that threads into preformed threads or
forms its own thread in one of the mating parts.
SDD Single draper drive.
Self-Propelled (SP)
Windrower
Self-propelled machine consisting of a power unit with a header.
SK Single knife.
SKD Single-knife drive.
Soft joint
A joint made with the use of a fastener where the joining materials are compressible
or experience relaxation over a period of time.
spm Strokes per minute.
SR Single reel.
Tractor Agricultural type tractor.
Truck A four-wheel highway/road vehicle weighing no less than 7500 lbs (3400 kg).
Timed knife drive
Synchronized motion applied at the cutterbar to two separately driven knives from a
single hydraulic motor.
Tension Axial load placed on a bolt or screw, usually measured in pounds (lb) or Newtons (N).
TFFT Turns from finger tight.
Torque
The product of a force X lever arm length, usually measured in foot-pounds (ft·lbf)
or Newton-meters (N·m).
Torque angle
A tightening procedure where the fitting is assembled to a precondition (finger
tight) and then the nut is turned further a number of degrees or a number of flats to
achieve its final position.
Torque-tension
The relationship between the assembly torque applied to a piece of hardware and
the axial load it induces in the bolt or screw.
UCA Upper cross auger.
Untimed knife drive
Unsynchronized motion applied at the cutterbar to two separately driven knives
from a single hydraulic motor or two hydraulic motors.
Washer
A thin cylinder with a hole or slot located in the center and is to be used as a spacer,
load distribution element, or a locking mechanism.
Windrower Power unit of a self-propelled header.
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