Single-tension

Single-tension is one of several ways to apply the necessary tension to drum heads. Single-tension systems largely replaced the ancient rope-tension methods in the late 19th Century and are still used today in lower-priced drums for student use.

In this system, one long tension rod with a threaded end extends through the hoop holding the top drum head and then down outside the drum shell to a threaded hole in the bottom hoop. There usually is a small guide halfway down on single-tension drum shells to keep the tension rods straight.

In older drums, the hoops are often held tight by separate clamps through which the threaded tension rod fits.

Tension is applied by turning a special key that fits into a hexagonal drive, but many bass drums (especially those models designed for concert use) have permanent wing-nuts permanently affixed to each tension rod, even on double-tension drums.