, 2 Rim
, 3 Tension rod, 4 Lug, 5 Snare butt
1 Drum badge and grommet, 2 Snare strainer, 3 Throwoff lever
A drum "hoop" or "rim" may be made of metal, wood, or other materials and is used to hold a drumhead against a drum shell, either with bolts through metal "claws" attached directly to a hoop, or bolts through holes in a flanged or die-cast rim. The bolts, called tension rods, are screwed into threaded "lugs" attached to the drum shell, in order to tighten and tune the drumhead. A drum key is a type of wrench often used to screw the tension rods into the lugs.
Spurs/bass drum legs, casings/lugs, and tension rods/tuning screws
This section needs expansion
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There are a number of components that make up a drum's anatomy. Some of these anatomical components vary dependent upon the type of drum, the manufacturer, and the year in which it was made. However, nearly all modern drums have the same essential components. Kick drums often have legs called spurs on either side of the drum shell. These spurs are used to prevent the kick drum from rolling side to side, to prevent the drum from sliding forward as it is being played and to provide overall added stability to the drum. Casings, also known as lugs, vary in shape and size. They all serve the same purpose as the receiving end of the drum tension rod (also known as a tuning screw) and provide the anchor point for the tension rods themselves. Casings are found on nearly all modern drums. The number of casings a drum has can vary from drum to drum and manufacturer to manufacturer. A drum can have as little as six casings and as many as twelve. Tension rods, also known as tuning screws, are threaded bolts that are placed around the rim of a drum and screw into the casings. They enable the musician to adjust the tension of the drum's head and affect its overall pitch, tone, and timbre. They come in many lengths and should also always have a tension rod washer that is often made of metal or hard plastic.
Snare drums will often have a "strainer" on one side and a "butt plate" on the other to hold the snare wires to the drumhead. Snare tension is controlled with a screw on the strainer. A strainer may also have a "throwoff" lever to move snares away from the drumhead, in order to prevent buzzing caused by other bass instruments while the snare is not in use, or to produce a tom-tom sound if desired.
While not required for operation, most drum manufacturers label their products by way of a drum "badge". The badge is a label attached to the drum shell with a grommet, which is embossed with the manufacturer's name or logo, and often a serial number as well. The grommet doubles as a "vent" hole for two-sided drums.
Drum mounts are fittings, normally attached to the drum shell, that enable a drum to be attached to a supporting bracket, stand or rack. Traditionally, smaller tom-tom drums are supported by mounts and known as hanging toms, while snare drums rest on a stand not attached to the drum, and floor toms and bass drums rest on their own legs.
Hanging tom mounts are of two main patterns:
- The Pearl 7/8" (22 mm) mount accepts a 22 mm steel tube perpendicular to the drum shell. The excess length of the tube intrudes through the drum shell, and a large hole is required for this. Developed by Pearl, this mount has been adopted by many other manufacturers, and the 22 mm tube has become a standard interface for many other mounts and stands, such as cymbal booms.
- The parallel mount accepts a solid bar parallel to the drum shell. There are many bar sizes and profiles, mostly either round and knurled or hexagonal. There is a some compatibility, but it is not universal. Some manufacturers such as Tama Drums and Gibraltar Hardware even produce a single fitting that can be used either singly as a hanging tom mount, or in sets of three to attach the floor tom legs.
Either of these patterns can also be used with a rim mount. Most fittings have provision for memory to reduce setup time.
Tom on 7/8" arm, showing the tube intruding into the shell
There are many other patterns, including:
- Similar mounts to the 7/8" but with smaller tube. Mostly used on toy and entry level kits
- Spade mounts on older kits and, traditionally, on timbales
- Mounts that accept a solid bar similar to the parallel mount, but perpendicular to the drum shell or at an angle close to this. Common on older kits, and on some high-level handmade kits from smaller makers.