Basic Watch Terms to Know


New to watches? Here are some basic terminology for watches that you might come across when learning about watches or acquiring your first timepiece.


Case

The main “body” that encloses everything in a watch. The case can be made in different materials from stainless steel to precious metals such as gold and platinum. You’ll also hear people referring to the caseback, which is the area on the back of the watch where you can either sometimes find engravings or see into the movement. Watch sizes are typically designated by the size of their cases, which are often measured in millimeters. A quick rule of thumb size guide:


Small - 33mm or less

Medium - 34 to 38 mm

Large - 39mm or more


Lugs

The lugs are the prongs protruding from the case that are used to attach watch straps and bracelets to the case. Lugs can come in many variations with incredible designs in some vintage pieces. Some examples of unique lug styles include teardrop lugs, flare lugs, and hooded lugs (among many others).

Crown

Typically located on the right side of the case, the crown is the knob that’s used to set the time, wind the watch, and set complications on the watch. On some watches, there are also crown guards to help protect the crown from any potential external damage that may otherwise occur. Crown guards are more likely to be found on tool watches.

Dial

One of the most critical, if not the most critical, aspects of a watch, the dial displays the time and may sometimes include sundials that display the date, time, or intervals timed on a chronograph. The dial of a watch is also an integral part of a watch’s design and can often showcase the brand’s artistic prowess.

Indices

The indices are used to indicate the hour markers on the watch and can come in many variations. Some common index styles include Arabic numerals, baton, Roman numerals, and round. On modern watches, the markers may also have functioning lume to help the wearer better read the time.

Hands

There are typically 2-3 hands on a watch that show the time: the hour, minute, and second hands. For watches with a GMT complication, there may also be a GMT hand that’s used to track the additional time zone. Some common styles include alpha, baton, dauphine, sword, and arrow.

Lume

Lume refers to the glowing material on the dial of the watch, most commonly found on the hands and indices to increase legibility in the dark. In vintage watches, radium and tritium were common used, but were radioactive (don’t worry the radium/tritium on older watches has likely decayed significantly so they aren’t harmful). As a result, modern watches now have LumiNova and Super LumiNova, which produces the same illuminating effect and is much more durable.

Bezel

The bezel is a ring that sits on the case of the watch that helps protect and keep the crystal in place and comes in a number of materials such as ceramic, aluminum, and steel. Bezels are also used to help the wearer track time in various contexts and can either be rotatable or fixed. For example, a diver’s watch may feature a uni-directional (only turns in one direction) bezel to help the wearer time their dive while a tachymeter may sit on a fixed bezel to measure speed, time elapsed, and distance traveled.


Example of a rotatable bezel that's used with the GMT hand to track another time zone.

Power Reserve

The power reserve of a watch is the amount of time a watch can run after it’s fully wound. The longer the power reserve, the more time a watch can run and the longer it may be able to keep time when it’s not worn. Some watches also have a power reserve indicator to show how much power is left on the watch (the less power, the less time you have before the watch stops running until it’s wound again).

Movement/Caliber

The movement is the powerhouse and engine of a watch. The entire mechanism is made up of many individual parts that work together to keep time. The more complications on a watch, the more complex and the more parts there will be on the movement (some movements have hundreds of parts!). Watchmakers will also typically refer to a specific movement they’ve developed as a particular caliber. Almost all watches will either feature a mechanical or quartz movement.

Automatic Movement

An automatic movement is a type of mechanical movement where the watch will wind itself as you wear it. After they’re wound, watches with automatic movements will continue to wind themselves as they’re worn so you don’t need to constantly wind the watch if you’re wearing it regularly.

Manual Movement

Manual wind movements are another type of mechanical movement where the watch needs to be wound once the “power” on the watch runs out. Unlike automatic movements, a manual wind watch does not continue to wind itself as its worn. This can be great for those who love to have a more “hands-on” experience with their watches since manual wind watches need to be wound regularly if worn often.

Quartz Movement

Quartz movements are powered with a battery and are typically more accurate than mechanical movements. They also tend to be much more durable, budget-friendly, and easier to maintain. In the 1970s, Seiko launched the first commercially available quartz watch, contributing to the quartz crisis in the watch industry where traditional watchmaking was challenged with a new, cheaper, and more efficient way of telling time and producing watches.