
extension of a threaded rod how to properly extend a

It is most commonly used for commercial floors or walkways, and bridges. But it can also be used for ramps, wash bays, platforms, and jetties.
To install an oil seal properly, the shaft must be undamaged. This is so the oil seal can do its job properly on the one hand, and to prevent it from being damaged during fitting on the other. In addition, it is very important to lubricate the shaft, the sealing lip and the bore with plenty of grease. This will allow the oil seal to slide more easily over the shaft and prevent dry running after the first rotation. The oil seal may also come into contact with the keyway, thread or other grooves when sliding over the shaft. By taping or covering the shaft at the location of these irregularities with oil-soaked paper, the oil seal can be mounted without damage to the sealing lip.
From this kind of standard immersion testing, one would expect that bisphenol-cured VDF/HFP/TFE fluoroelastomers would not give good service life as oil seals. Similar tests with other elastomers, such as HNBR, silicone, and acrylic rubbers, show less loss of elongation. However, it is found that, in actual service, FKM shaft seals6 have much longer service life than seals of the other elastomers. In a Japanese study of FKM lip seals, rear crankshaft seals from high-mileage automobiles (70,000–280,000 mi ie, 110,000–450,000 km) were collected and examined. No serious oil leakage was found when the seals were removed from the engines. Some deposits were found around the seal lip and on the garter spring holding the lip against the shaft. No surface cracks were found on the seal lip, and only minor crazing on the crankcase side of the flexure portion of the seal in some samples. The seal compositions were not noted, but most were probably VDF/HFP/TFE elastomers with 68–69% fluorine content.