GRAPHALLOY Bushings are designed for each specific installation. They are pressed into their housings and reach their final size 24 hours after the pressing operation. Bushings may be pressed in dry, but bushings should be dipped in water, solvent or kersoine for easier installation.
FOR ROOM Temperature Application
A GRAPHALLOY Bushing designed for room temperature application is pressed into the housing with an interference fit of + .005" or more, depending on the size of the bushing. Because of their strength and resiliency, it is not necessary to shrink fit GRAPHALLOY Bushings into their housings.
FOR HIGH Temperature Application

GRAPHALLOY Bushings designed for higher temperature application will have an interference fit of + .010" to .025", depending on:

1) The maximum temperature to be experienced,

2) The material of the housing and shaft, and

3) The size of the I.D. of the housing.

GRAPHALLOY's thermal expansion coefficient is only about half steel's coefficient of thermal expansion. The busing must be designed, therefore, with adequate press fit (+.010" to .025") to make up for the greater expansion of the housing at elevated temperatures. Otherwise, the housing would expand beyond the bushing O.D. and the bushing would not remain tight in the housing.


Normal Method of Pressing GRAPHALLOY Bushing into Housing by Arbor Press or Hydraulic Press
Bolt-and-Nut Method of Pressing GRAPHALLOY Bushing into Housing

Each GRAPHALLOY Bushing is normally pressed into its housing by means of an arbor press or hydraulic press. The housing I.D. should have a chanfer of 1/32" X 45o to facilitate entry of the bushing. A stepped mandrel or arbor should be used to insure that the bushing will be positioned straight with the hole before installation. The small O.D. of the arbor should be 1/16" smaller than the I.D. of the bushing, and the large O.D. of the arbor should be larger than the O.D. of the bushing. The pressing motion must be continuous with no interruption until the bushing is completly in place.


Where more practicable, the bushing may be pressed into the housing by the bolt-and-nut method; that is, with a plate against the upper end of the bushng. The nut must be continuously drawn up!