Ewart links

The Ewart links are usually cast in one piece with no separate bushings or pins. The material used is generally malleable iron, although steel is also extensively employed. As a general rule the maximum speed at which this type of chain is operated is about 400 ft/min, and even at that speed it is apt to be quite noisy. Because the links used in this chain are not machined and the pitch is not very uniform, the teeth of the sprockets used with them are, in turn, generally not machined. 

Figure 3-37. Closed Ewart link or pintle link [8].

Figure 3-38. Ewart link with bushing (API chain) [6,16].

There are six types of chains used for power transmission. These are roller, silent (inverted tooth), offset link (Ewart with bushing), detachable (open Ewart), pintle (closed Ewart), and bead,... 

Some of these are shown in Figure 3-26. Because most modern power transmissions use roller chains, silent chains or the offset link (Ewart) chains, these will be the only chain types discussed since they are quite important in oil field applications. 

Offset Link (Ewart with Bushing), API Chain... 

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