316L Stainless Steel

316L stainless steel is a marine-grade of stainless steel that has extra-low carbon content and is extremely resistant to corrosion such as seawater or acidic liquids. 316L is also magnetic resistant, unlike the general-use stainless steel grade of 302 or 304. To qualify as 316L stainless steel, the amount of carbon cannot exceed 0.03%. This decreases the risk of carbon precipitation, making it a better option for welding to ensure maximum corrosion resistance. Therefore, 316L is also widely used in diving equipment.

Anodized Aluminum

A material that made the bezel inserts before the usage of ceramic. A benefit of aluminum bezels that many watch enthusiasts and collectors love is the fact that they do age and fade. Many watch enthusiasts enjoy the fact that the watch ages and shows natural signs of wear – that it gives it character.

ANTI-REFLECTIVE COATING

Anti-reflective coating (or AR Coating) is a type of optical coating that is applied to the crystal of certain watches to prevent it from reflecting light. The objective of AR coating is to improve readability and performance of the crystal while keeping the clarify of the glass to its best.

ARROWHEAD HAND

Hands often found on vintage tool watches that are shaped in the form of arrow heads.

AUTOMATIC

A watch that features a rotor winding the mainspring without the need for manually rotating the crown. Also known as self-winding as its movement spins either one or both ways as the wrist moves throughout the day. 

BEATER WATCH

A watch that you can wear everyday as a beater with care-free confidence, which you are not flustered when itbears some marks of being used and abused on your wrist. A little patina makes the watch more worn in andmakes for good character.

BEZEL

An external ring on a watch that surrounds the crystal. It can either be fixed or rotate to provide additional functionality, such as measuring airtime on dive watches. Some rotating bezels are internal (under the crystal), usually controlled by a second crown on the watch case.

BEZEL INSERT

Some professional tool watch models use the bezel as a removable insert to indicate different functions.

BRUSHED FINISH
(SATIN FINISH)

With a brushed finish or a satin finish, you can clearly see lines on the watch case and bracelet. These lines are not from stainless steel but are brushed on by a watchmaker using a steel brush. This can be done using stationary tools, as well as specialized hand tools.

CASE

The physical container housing all parts of the watch, including the movement, dial, crystal, and crown. Wristwatch cases generally have two lugs on either end to attach to a bracelet or strap.

CASE BACK 

The bottom lid that closes the back of the case and seals in the movement and dial.

CERAMIC

From the Greek keramos meaning fired pottery. A solid, non-metallic, and non-organic material used as a replacement of metal in bezels, cases, and bracelets. Generally made from aluminium and zirconium oxides (polycrystals). It is virtually impervious to scratches, and its colour is unaffected by ultraviolet rays of the sun.

CHAMFER

An angled, sharp cut found on top edge of the lugs on some high-end tool watches, often obliterated by multiple polishes. This is usually done to the edges of watch parts to enhance aesthetics and often considered as a distinguishing feature of a superior quality watch.

CHRONOGRAPH

A type of tool watch that tells the time and features an additional stopwatch function. The timing element can be stopped and started without interfering with the ability to tell the time. 

CROWN

A knob on the side of a watch case, usually at 3 o’clock, used for setting the hands on a watch, and the day (and date) where applicable. It is also used for winding the mainspring of a mechanical watch. The crown is also known as a winder or winding stem. 

CROWN GUARD

The two metal protrusions on the watch case that flank the crown and protect it from damage, usually a feature found on a professional tool watch.

CRYSTAL

The transparent cover protecting the dial, usually made from sapphire, hardened glass, or acrylic.

DATE

A feature indicates the day of the month in numerical fashion, usually at the 3 o’clock position.

DEPLOYANT BUCKLE
(DEPLOYMENT BUCKLE) 

A butterfly type closing buckle, considered as a more sophisticated type of watch strap buckle than the common pin buckle that folds in on itself and snaps closed. The strap is initially adjusted by securing a pin into the proper hole, allowing the wearer to then simply release the buckle to remove and refold to wear. It extends the life of a leather strap and allows it to function more like a bracelet.

DIAL

The face of a watch which displays the hands, time indicators and complications under the crystal. On watch models with date, an aperture is cut in the dial to allow the number wheels to be read.

DIVE WATCH

A water-resistant watch specifically designed for underwater use. Dive watches generally require a rotating bezel to track airtime, excellent legibility with ample luminescence and a significant depth rating (a minimum of 100 meters). Professional dive watches usually meet established standards such as ISO 6425, which requires specific minimum depth ratings, visibility, bezel indications and more.

FIELD WATCH

A watch with tool-like properties in a relatively simple, military style with a focus on robustness and legibility. The style originates from trench watches used by soldiers in World War I. Most field watches use a dark dial with bright (mostly white) markings and hands.

GASKET

A ring made of rubber, plastic or other materials used to seal the gaps between the case and the case back, crystal and crown to prevent water, dust, or other contaminants from entering the watch case and damaging the movement inside. Gaskets should be checked every couple of years to maintain water resistance.

GMT

Greenwich Mean Time (GMT) is the standard mean solar time at the Royal Observatory in Greenwich, London, counted from midnight (00:00 hour). It is used to calculate the time divided into 24 time zones spread across the world, with the zero zone being based in Greenwich, London. Travelling east or west would mean adding or subtracting one hour according to the determined time zones and it is the same all year round and not affected by Summer Time or Daylight Savings Time. In watchmaking, GMT is often used to indicate a watch that can display a second-time zone in a 24-hour mode.  

HACKING SECONDS 

Introduced in the 1970’s, also called “Stop Seconds”, this feature will stop the seconds hand when the crown is pulled out, allowing for a precise setting of the time, or synchronizing of multiple timepieces.

INDICES

The markings on the dial of a watch used to represent the hours in place of numerals. In higher-end watches, these are usually “applied,” or attached to the dial, rather than printed on.

JAMES BOND

The nickname for an iconic vintage diving watch with a striped textile NATO-style strap, which was worn by actor Sean Connery in the James Bond movies.

JEWELS

Synthetic gemstones used inside mechanical watches as bearings to reduce friction on pivots of the gears and extend the life of the movement. 

LOLLIPOP HAND

Called such due to the lollipop-like shape.

LUGS

The four extensions of a wristwatch case (two on each side) hold the bracelet or strap. The two ends of the lug hold a spring bar that is used to fix the bracelet or strap to the case. 

LUMINOUS

Luminous hands and/or hour markers are a standard feature on many tool watches. The hour markers and/or hands have a coating which will illuminate in the dark so you can tell the time when there is insufficient light.  

LUMINOVA
(SUPER-LUMINOVA)

In 1993, a Japanese-based company, Nemoto & Co. developed a new phosphorescent pigment technology, called LumiNova. RC Tritec AG was founded the same year as a Swiss-based company that holds the licensing rights to produce and distribute LumiNova under the registered name Super-LumiNova.

MERCEDES HANDS

This term refers to those hour hands with a three-pointed star (known as the Rising Star) sitting near the tip, with each point representing the three modes of transport: land, air, and sea. The distinctive design of this hand is a cornerstone feature in tool watches with its practical yet visually appealing design.

MILANESE BRACELET

Named after the city of Milan where they originated from, Milanese mesh bracelets were inspired by 13th-century chain mail, the distinctive design has a tight meshwork, which makes it especially smooth to the wrist. 

MAXI DIAL

The term refers to the larger or oversized markers, hour, and minute hands on certain tool watches.

METEORITE DIAL

A dial made from a thin layer of a meteorite that fell from space. Because of naturally occurring patterns, no two are alike. 

MILSUB

One of the rarest and most sought-after military divers’ watches was once soldiers’ basic equipment. They were designed and built to be robust and reliable watches that were to be perfectly legible at profound depths. 

NO DATE

A term indicates the absence of the date feature on watches.

NO HOLES CASE

A tool watch case that does not have pierced lugs.

PATINA

A term often used about vintage watches to describe the discolouration of tritium or radium-based luminescent material (or “lume”) on hands and markers, the discolouration of dials, and even the metal of certain kinds of cases. It can range from off-white to a rich brown hue. The desire for patina is strong within watch collector communities and it is likely to continue shaping the watch market for decades to come. 

PILOT’S WATCH

One of the most popular types of tool watches, inspired by aviation. A pilot’s watch is often oversized and has alarge, very legible dial, anti-magnetic properties, high shock resistance and should withstand sudden changes intemperature or pressure. A pilot’s watch dial has clear, highly contrasting markings, including a triangularmarking at 12 to identify the watch’s up from down in mid-flight.

PVD

Physical vapour deposition (PVD) is a resilient thin coating applied to a case to add colour for aesthetic and/or protection purposes. The coating is mainly composed of chromium carbide, which improves resistance to wear and corrosion by increasing the hardness and oxidation levels. While PVD is mainly applied for its durability, the decorative layer is relatively thin and may wear if subjected to repeated abrasions. The warranty does not usually cover such cases.  

REHAUT

An alternate term for the inner reflector ring just above the dial on some modern tool watches.

RED TRIANGLE

This term refers to the distinctive red triangle at the 12 o’clock position of the bezel.

SAPPHIRE CRYSTAL

A high-end synthetically grown transparent material for professional tool watch crystals today. Made by crystallizing aluminium oxide at very high temperatures, it is chemically the same as natural sapphire, but without the small amounts of other elements such as iron, titanium or chromium that give the gemstones their colours. Sapphire (whether natural or synthetic) is one of the hardest substances, measuring 9 on the Mohs scale, a system for rating the relative scratch hardness of materials. (Diamond measures 10, the highest rating, and the hardest steels are 8). That’s why It is considerably more scratch resistant than either acrylic or glass crystals.

SATIN FINISH
(BRUSHED FINISH)

With satin or a brushed finish, you can see lines on the watch case and bracelet. These lines are brushed on by a watchmaker using a steel brush. This can be done using stationary tools, as well as specialized hand tools. 

SCRATCHPROOF

Materials or objects that are not scratched when rubbed against a hard surface. For example, a scratchproof sapphire crystal. 

SCREW-DOWN CROWN

By screwing the crown into a matching threaded tube that is part of the case, the crown has a gasket that is compressed & sealed when tightened – thus ensuring water resistance. 

SPORTS WATCH

A watch that is highly legible, durable, shock and water-resistant, and generally designed to withstand the rigours of any sport. 

SPRING BAR

Small bars with retractable end pins (via an internal spring) are used to attach a strap or bracelet to the case lugs. 

STAINLESS STEEL

An iron alloy specially designed for both corrosion resistance and strength, comprised of elements including chromium, nickel, carbon, silicon, and manganese. It is the most common metal used for watch cases and bracelets.  

STRAP 

A leather, canvas, rubber, or other non-metal band attached to wristwatch lugs to secure the watch to a wrist (alternative to hardened bracelet); a metal version is referred to as a bracelet.

SUB

One of the most popular tool watch models in the watch history. It was first launched in the 1950’s as a divers watch for its ability to withstand moisture and water.

SUNRAY BRUSHING

A pattern of imperceptible lines, like the sun's rays, intersecting at the same central point. It is created using a brush, usually with metal filaments.

SUPER-LUMINOVA (LUMINOVA)

In 1993, a Japanese-based company, Nemoto & Co. developed a new phosphorescent pigment technology, called LumiNova. RC Tritec AG was founded the same year as a Swiss-based company that holds the licensing rights to produce and distribute LumiNova under the registered name Super-LumiNova. 

SWORD HANDS

A highly sought-after design named after its sword-like shape which was specially developed for the military. It was originally designed to make the hour hand visible even when it was covered by another hand. 

TACHOMETER

A tachometer also referred to as a tachymeter, is typically located on the bezel of a chronograph watch. It is a printed or engraved scale for calculating speed over a measured distance (or measuring distance based on speed). 

TOOL WATCH

A term referring to a watch designed with a specific function or task in mind. It can be a simple rugged field watch, a pilot’s watch, a highly antimagnetic watch, a chronograph, etc.

TRITIUM

A slightly radioactive substance containing tritium that collects light and is used to allow the hands or hour markers to glow in the dark from the 50’s until the mid-90’s so they can be read in the dark. The radiation is relatively low that there is no health risk. Watches bearing tritium are often marked as such, with the letter T on the dial near 6 o’clock.

TROPICAL DIAL 

A term referring to a specific dial patina usually on matte, black, professional tool watch models with the colour turning a dark brown.

TWO-TONE
(2-TONE) 

This phrase is used to describe a watch made of two different metals or colours such as stainless steel and gold. 

UNI-DIRECTIONAL ROTATING BEZEL

A bezel that can only be rotated in a counterclockwise direction and is used to monitor elapsed time. A ratcheting mechanism is placed to prevent the bezel from rotating in the other direction. This feature is found on divers' watches as a fail-safe to protect a diver from overestimating the remaining air supply in the case the bezel was accidentally moved from the original positioning. 

UNPOLISHED

A term denoting a watch that has not been polished ever in its life, very desirable to preserve the bevel on sports watches.

VINTAGE TOOL WATCHES

A generic term for any tool watch that is 30 years or older. 

WATER-RESISTANCE

A watch's water resistance is measured in bars (a unit of pressure where 1 bar equals 1 atmosphere or atm). Manufacturers generally indicate this water resistance in metres (m), feet (ft), or atmospheres (atm). A watch that is described as water-resistant, must be tested to the criteria set out in NIHS 92-10 (equivalent to ISO-2281 international standard). These watches are for everyday use, such as leisure swimming. They can be used in conditions of changing air pressure, water pressure, or temperature. A diving watch is made to be worn underwater at a depth of at least 100 metres (330 feet). It must include a time control device and fully conform to the criteria set out in NIHS 92-11 standard (ISO 6425).

WATER-RESISTANT

A watch that is water resistant can withstand or resist water to a certain extent.