The typical Slide Bearing configuration, most often called out as FC-1010-CS, is made with two Fluorogold® elements. Both the Upper and Lower elements are 3/32” thick Fluorogold® bonded to 1/8” thick carbon steel. Fig. 1 and Fig 2.
Fig. 1
Fig. 2
Shows the Upper and Lower Members both with Fluorogold® bonded to steel backing plates. Note the slot that allows the Upper Member slide with expansion and contraction. The Lower member remains stationary.
Occasionally the design will employ the same lower element but require the upper plate to be made of stainless steel with no Fluorogold attached. (Fig. 3) The upper stainless element slides on the lower Fluorogold® surface. This will appear on drawings as call-out #SB-0016-SS(2b), with the 0016 representing the thickness of the Stainless Plate, in this case 1/16”. Often the upper stainless element is 1/8” or 1/4”, and SS 304 being the grade.
Fig. 3
A typical lower member with Fluorogold® bonded to carbon steel. The upper is polished stainless steel.
There are two reasons an assembly will be designed like this:
- With only one Fluorogold® surface the bearing assembly will provide greater compressive strength (see below)
- The upper element can be reduced in thickness by as much as 5/32”.
A standard FC-1010-CS (Fig. 1and 2) with two Fluorogold® elements will reach a maximum compressive strength of 2,000 psi. By using only one Fluorogold® element the maximum compressive strength increases to 3,500 psi. Note these figures apply at a normal operating temperature of 100°F. As the operating temperature increases the psi limits decrease.
To support the higher load the bearing requires a lower co-efficient of friction between upper and lower elements. This means polishing the surface of the Stainless Steel to at least a 2B finish. That is, a surface where the difference between the high and low points is no more than 20 millionths of an inch. More precise polished finishes are available, up to a #8 Mirror, each reducing the coefficient of friction and increasing the bearings performance.
Slide Bearing FC-1010-CS 1/2 NR shows a good example of a lower element of Fluorogold® bonded to carbon steel which is bonded to a reinforced pad to allow for rotation. (Flexibility) The upper element consists only of polished 1/16” thick stainless steel.
As always, the upper element of the bearing assembly should completely cover the lower element at all times. The oversize dimensions of the upper element are determined by the anticipated movement. This same requirement holds for both Stainless and Fluorogold ® upper elements.