The hooked metal needle is the principal knitting elements of the knitting machine. Priror to yarn feeding, the needle is raised to clear the old loop from the hook and to receive the new loop above it on the needle stem. the new loop is then enclosed in the needle hook as the needle starts to descend. The hook then draws the new loop down through the old loop as the altter slides over the outside of the descending bridge of the closed hook. All needles must therefore have some method of closing the needle hook to retain the new loop and exclude the old loop.
The fabric loops are always drawn form the needles on the side remote from their hooks. When two sets of needles are employed, either arranged vertically back-to-back or at some other angle to each other, each set of hooks will face away from the other set and the fabric will be produced and drawn away in the gap between the two sets.