Rods and lugs

Placed vertically through the holes in the [hoops] are tension rods which are basically bolts, threaded at one end and sporting a square top at the other to accept a drum tuning key. Older kits tended to use slotted tops (like the top of a screw) however these are not generally manufactured for modern drums.

A tension rod fits into a 'lug' or 'nut box' that contains a threaded barrel into which the tension rod is screwed. The nut boxes are attached directly to the shell of the drum, the exception being free-floating shells where the lugs fix to a ring on the bottom edge of the drum. Over recent years as players become more demanding and the understanding of how drums operate is becoming increasingly applied, manufacturers have been seeking to reduce the amount of lug contact points and the 'footprint' of each lug contact point. This is working towards permitting the drum shell to resonate more freely and put more of the sound of the wood into the drum. Many manufacturers have developed 'low-mass' lugs expressly for this purpose.