The Parts of a Bell


The mouth of a bell refers to its entire opening where its clapper hangs. This smooth part contributes to creating the characteristic chiming sound associated with bells.

Discover all the components to ensure a bell rings properly during your next rehearsal! Impress your choir director by learning more about these essential pieces!


Be it part of a massive tower bell weighing tons, handbells spanning five octaves, or an individual bell that rings the hour, bells are instruments made in the shape of cups with pieces hanging inside that hit their sides to produce sound and create sound waves that make sounds. Bells can be used to announce events, signal mealtime, or tell time, yet each bell also represents centuries of bell founding and campanology history and craftsmanship.

A bell’s crown is the top portion of its head, hanging from a yoke or other structural support and providing its distinctive sound. This area can also be decorated with engravings, designs, or other ornaments to provide added adornments, traditionally made out of copper-tin alloy for optimal tone production.

The crown of a bell houses its clapper, which strikes the bottom of the bell to make it ring, held by a baldric, traditionally leather strap with multiple thicknesses that loops securely over it for safety. Over time and repeated use, however, baldrics can wear or become detached from crown staples, which could potentially compromise bell performance and cause irreparable harm to its contents.

An electric bell is powered by a coil of wire, which acts as an electromagnet when current flows through it, functioning like an electromagnet when switched on. Once switched, the current pulls an iron strip with a hammer at one end to strike the bell’s gong and produce sound. Over time, repeated striking wears down parts of its structure known as striking points, which diminish its tone; filling these points typically involves welding new metal onto its design to restore tone levels.


The shoulder is a ball-and-socket joint composed of three bones–the collarbone (clavicle), shoulder blade (scapula), and upper arm bone (humerus). Its structure includes muscles, ligaments, and tendons that support its movement in different ways, making it one of the most mobile joints in your body, allowing a range of movement options.

The head of the humerus fits into a shallow socket called the glenoid cavity in the scapula, part of the shoulder blade. To keep its position secure and allow movement without damaging soft tissues around its joint, its joint is stabilized by an array of muscles and tendons known as the rotator cuff – this allows movement but also keeps the head of the humerus from shifting too far forward in its socket, thus keeping this joint healthy and viable.

As with other muscles, shoulder muscles consist of bundles of fibers that contract and tighten. Rotator cuff muscles play a pivotal role in lifting arms over your head, rotating them sideways and across your body while moving them up, down, or backward.

Rotator cuff injuries are one of the leading causes of shoulder discomfort. They may occur suddenly (due to an accident, for instance) or over time as you age.

Rotator cuff damage can also result from overuse or repetitive activities, with tear tears potentially causing pain from shoulder to elbow. Your doctor may recommend surgery to repair this area, such as replacing bone fragments or replacing or repairing ligaments with healthier ones, or even placing screws to secure fractures in severe fracture cases.


When applied to garment construction, human waists are defined as the narrowest point of their torsos; however, this term refers to an expanse extending from just beneath the rib cage to hips measured as waist width. Although waist measurements and definitions can vary widely for people outside conventional norms, inaccurate reports and measurements lead to commercial waste and customer dissatisfaction – prompting ISO standardization with more inclusive measurement criteria that account for anatomical variations that will allow accurate waist measurement across garment design projects.

Mii-dera no Bansho in Shiga Prefecture of Japan features these curved bells from their evening bell, called Mii-dera no Bansho. Each bell hangs from wooden beams with hooks attached for hanging purposes, while a wooden pole serves as its source.

Ancient Greeks employed handbells for liturgical and secular uses, crafting metal bells into various shapes to produce specific notes. Early European church bells featured the campaniform design: narrow, rounded top; long straight waist or sound bow which extended downward; flared mouth which struck outer sides of the resonating cavity; flared lip which struck outer sides. By the 14th century, this archaic shape had become the dominant form in Europe.

Modern chime tower bells are engineered for optimal musical resonance by minimizing the amount of exposed material, thus minimizing weight and overturning when struck. Truncated bells may also be made lighter so as not to cause unintended overturning when struck; in these instances, truncated ones have identical pitch but more responsive vibrational responses due to thinner walls and more lightweight construction.


An anatomical structure that makes up the mouth margin in most vertebrates and comprises the surface epidermis, connective tissue, and (in typical mammals) muscle layer. When contracted, the muscles of the lips cause them to bend slightly upward or outward, causing smiles to form. It is also called labium, Lippa, Lippe, or lappa. It also has a spherical projection like that found on flowers or horns, a bell-shaped receptacle such as that found on cowslip’s lips, and anything shaped like a bell-shaped control.

Webster’s New World College Dictionary, 4th Edition by Houghton Mifflin Harcourt; all rights are reserved by them and used with their permission.


Bell mouths are bell-shaped openings at the end of tubes often used in ventilation systems to reduce noise, turbulence, and pressure loss by decreasing air velocity at the system’s entry point. Their design typically allows initial air velocity to start low before gradually increasing up to the specified system air velocity; commonly used on return air ducts but also extract or supply air ducts.

Communications bell-mouth fittings, which are specialized adapters that cover the inlets of underground conduits, also use this fitting. Their primary purpose is to protect cables or pipes being pulled through and reduce entrance pressure losses for lines.

Bell Founding involves pouring molten metal (usually bronze) into an inner mold or cope contoured to match a bell’s desired shape and an outer core prepared with loam or sand as the outer mold or core. When complete, this newly fashioned bell will be flattened out and formed into its final form by hammering. Cooling may take as long as one week, depending on its size, to prevent porosity and cracking from developing over time.

Nordfab QF bell mouth hoods feature flared design to maximize capture ratio and come in 3″ to -24″ sizes. Connected via either a male or female connector, these hoods can be installed directly alongside or 90 off any Nordfab duct fitting for optimal results. For more detailed measurements for each size, click on one of the images below.