GLOSSARY

Click the buttons below to view the glossary.

GLOSSARY OF WATCH TERMINOLOGY AND PARTS

A to Z guide to the most important terms used in watchmaking.

Navigating the wonderful and expansive world of timepieces is a breeze once you get used to the specialised vocabulary commonly used to describe watches and watchmaking. To make things even easier for you, here is a specially curated list of horological terminology that you will encounter in your appreciation of Rolex and Tudor watches.

A

A

ANALOGUE

A form of display on a watch that uses traditional hands, as opposed to digital indicators.

ANTI-MAGNETIC

A fortifying feature inside a watch that helps it to become resistant to magnetic interferences and hence, maintain its accuracy. Some watches use an inner case made of soft iron for this feature, while others use specially developed components made of magnetic-resistant alloys and materials.

AUTOMATIC WATCH

A type of mechanical watch that winds itself automatically when worn on the wrist. This is achieved by a weighted rotor that spins and winds up the mainspring with each motion of the wrist. (See also: ‘Mainspring’ and ‘Rotor’.)

B

B

BALANCE WHEEL

A component at the heart of the regulating system of the watch. Like a pendulum in a clock, the balance wheel oscillates back and forth to control the watch’s timekeeping accuracy.

Barrel Wheel

A drum-like component that holds the watch’s mainspring. Together, they store the watch’s energy and power reserve.

Bezel

The rim-like component that frames the perimeter of a watch dial. A bezel can be plain, decorated or etched with markings to help to measure speed, distance or elapsed time. It can also be fixed in position or, depending on usage, rotated bi- or unidirectionally.

C

C

CASE

The main housing of a watch. The case comprises the bezel, as well as the lugs – the four protruding ends of the case where the strap or bracelet is attached.

Calibre

Refers to the assembled components housed inside a watch’s case that make it work. Interchangeable with the term ‘movement’, a calibre is usually referenced by a specific code and number that identifies its origin, type and manufacturer.

Chronograph

A chronograph is a type of watch that allows the wearer to measure separate intervals of time on top of regular time display. A typical chronograph is activated by one or several push buttons that start, stop and reset the interval timer, which can last from a fraction of a second to 12 hours.

COSC

Short for ‘Contrôle Officiel Suisse des Chronomètres’ (Official Swiss Chronometer Testing Institute), a non-profit establishment that tests Swiss-made chronometers. For watches to be COSC-certified, they need to meet stringent standards of accuracy and precision. For instance, COSC-certified mechanical watches are only allowed a variation of -4 to +6 seconds per day. Both Rolex and Tudor watches register performance and accuracy that far exceed COSC requirements. Rolex conducts its own in-house quality assessment with the Superlative Chronometer certification that boasts far more stringent standards. (See also: ‘Superlative Chronometer’.)

Crown

A component usually found on the side of the case, which allows the wearer to wind the watch. The crown is connected to the rest of the movement via a winding stem.

D

D

Dial

The face of the watch. The dial contains all the essential markers and displays to indicate the time, as well as any additional information such as day, date, moon phase, power reserve and so on.

Domed Sapphire Crystal

A sapphire crystal is an ultra-hard and virtually unbreakable piece of synthetic lens that is set in a watch case to cover and protect the dial. Sapphire crystals can come with a flat design or, in some instances, domed with a convex top to evoke the look of vintage watches. There are also double-domed sapphire crystals which, as the name suggests, are convex at the top and bottom. This design ensures the dial doesn’t look distorted when the wearer is viewing it from an angle.

E

E

Escapement

A system of mechanisms comprising the balance spring, balance wheel, escape wheel and escape lever. The escapement is often referred to as the mechanical heartbeat of a watch. Its purpose is to regulate and maintain the accuracy of the timepiece.

F

F

Frequency

Refers to the rate at which a movement’s balance wheel oscillates. Movement frequency can be measured in hertz (Hz) and vibrations per hour (vph). Modern mechanical watches run at 2.5 to 4Hz (18,000 to 28,800 vph). Rolex and Tudor’s movements all run at 28,800 vph.

G

G

Gear Train

A system of gears that link up to transmit power from the mainspring to the escapement.

H

H

Hand-Winding Watch

A hand-winding watch requires the wearer to wind it up manually, so that the mainspring gets tightened up and stores ample power reserve to drive the watch. Also known as ‘manual-winding watch’.

Hairspring

Also known as a balance spring, a hairspring is used in a mechanical watch and its function is to help control the frequency of the movement. A flat spiral spring, the hairspring is fixed within the balance wheel and pivoted at the middle. As it coils and uncoils, the hairspring causes the balance wheel to oscillate. This action impacts the rate and speed at which the wheels of the movement turn. (See also: ‘Balance Wheel’ and ‘Escapement’.)

I

I

Integrated Bracelet

An integrated bracelet is one where the metal bracelet is joined to the case such that it appears as a seamless entity.

J

J

Jewel

Not to be mistaken for precious stones, jewels, usually listed in a movement’s specification sheet, are synthetic rubies that are press-fit into holes, or used as caps or pins in the movement to help reduce friction between the metal components.

M

M

Mainspring

A mainspring is thin blade made of flexible steel that is housed in the barrel wheel. When a mechanical watch is wound, the mainspring coils up to store the energy that is required to power the watch.

Movement

The ensemble of fully assembled mechanical components that perform the operations of a watch. Movements are divided into two main categories: mechanical movements that comprise entirely mechanical parts, which can be hand- or automatic-winding, and quartz movements, which are powered by batteries and are regulated electronically by quartz oscillators. (See also: ‘Calibre’.)

P

P

Power Reserve

A watch’s power reserve indicates its total running time when fully wound. All of Rolex’s watches with Superlative Chronometer certification, as well as Tudor’s watches with manufacture movements, offer an estimated 70 hours of power reserve. This is significantly higher than the average amount of power reserve in regular mechanical watches, which may range between 36 to 42 hours.

S

S

Satin-Brushed

A finishing technique that scores or ‘brushes’ the surface of a watch’s metal components using specialised tools, so that the surface bears a textured appearance comprising a multitude of close and tiny parallel lines.

Sub-Dial

Or subsidiary dial. A smaller indicator on the dial of the watch typically used to display auxiliary information such as small seconds, moon phase, and chronograph elapsed time, amongst others.

GLOSSARY OF WATCH TERMINOLOGY AND PARTS

A to Z guide to the most important terms used in watchmaking.

Navigating the wonderful and expansive world of timepieces is a breeze once you get used to the specialised vocabulary commonly used to describe watches and watchmaking. To make things even easier for you, here is a specially curated list of horological terminology that you will encounter in your appreciation of Rolex and Tudor watches.

C

C

Cerachrom

A monobloc bezel or monobloc bezel insert, developed and patented by Rolex. Cerachrom is made of extremely hard, virtually scratchproof ceramics that use zirconia or alumina as a base material, featuring colours that are unaffected by ultraviolet rays. In addition, thanks to its chemical composition, the high-tech ceramic is inert and cannot corrode. For optimum legibility, the moulded graduations, inscriptions and numerals are coated with a thin layer of gold or platinum via Physical Vapour Deposition.

Chromalight

Luminescent display emitting a blue glow in dark conditions. Rolex’s watch hands, hour markers and other elements of the display are coated or filled with Chromalight, a high-performance luminescent material that is exclusive to the brand. Chromalight’s intensity and luminosity duration far outperform watchmaking standards.

Chronergy

Optimised Swiss lever escapement developed and patented by Rolex. The Chronergy escapement is developed based on extensive research that led to a new design for the pallet fork and escape wheel. Both redesigned components are manufactured from nickel-phosphorus, an alloy that renders them resistant to magnetic fields. Their innovative geometry offers the Chronergy escapement a 15 per cent improvement in energy efficiency compared to regular Swiss lever escapements, the standard in mechanical watches.

Crownclasp

Concealed folding clasp designed and patented by Rolex, opened using a lever in the shape of a Rolex crown.

Cyclops Lens

The Cyclops lens, a name derived from the one-eyed giants in Greek mythology, was patented by Rolex in the early 1950s. Since 1953, it has magnified the date display in the aperture of many watches in the Oyster Perpetual collection for greatly enhanced legibility.

E

E

Easylink

Rapid comfort extension link developed by Rolex that allows the length of the watch bracelet to be adjusted easily. Opening or folding back the link allows the wearer to extend or shorten the bracelet by approximately 5 mm.

Everose Gold

An exclusive 18 ct pink gold alloy, developed and patented by Rolex, and produced in its own foundry. The composition of the alloy lends it a unique colour – a pink hue with an extraordinary sheen unlike any other that lasts for generations.

F

F

Fliplock

Fold-out extension fitted on the majority of the Sea-Dweller and Rolex Deepsea divers’ watches. It allows the Oyster bracelet to be lengthened by approximately 26 mm for wear over a diving suit.

H

H

Helium Escape Valve

Safety valve patented by Rolex in 1967 for divers’ watches designed for deep-sea diving. The helium escape valve allows excess pressure that builds up inside the watch case to be released during a diver’s decompression phase in a hyperbaric chamber. It features on the Rolex Sea-Dweller and Rolex Deepsea.

O

O

Oyster Case

The world’s first waterproof wristwatch case, pioneered by Rolex in 1926. It is a revolutionary system in which the case back and winding crown are hermetically screwed on to the case. The Oyster case is featured on every Oyster Perpetual model, guaranteeing waterproofness to a depth of 100 metres (330 feet).

Oysterflex

Innovative bracelet developed and patented by Rolex. It combines the robustness and reliability of a metal bracelet with the flexibility, comfort and aesthetics of an elastomer strap. At its core lie two flexible metal blades – one for each section of the bracelet – overmoulded with high-performance black elastomer.

Oysterlock

Oysterlock is a safety clasp system developed and patented by Rolex, designed to prevent accidental opening and ensure secure fastening of the bracelet. Housed inside a curved cover that seamlessly integrates with the bracelet, the Oysterlock comprises a click-down safety catch, a patented snap-fit lever, and a spring-loaded lever to prevent accidental opening.

Oystersteel

Stainless steel alloy developed for Rolex, which offers an exceptional sheen. Oystersteel belongs to the 904L steel family – alloys whose excellent anti-corrosion properties are comparable to those of precious metals. In 1985, Rolex became the first watchmaking brand to use 904L stainless steel for cases of all its steel watches.

P

P

Parachrom Hairspring

Patented in 1997, the Parachrom hairspring is developed and manufactured by Rolex from an alloy of niobium, zirconium and oxygen. It has the advantage of being insensitive to magnetic fields, being extremely stable when exposed to temperature fluctuations, as well as remaining up to 10 times more accurate than a traditional hairspring in case of shocks, thereby enhancing the movement’s chronometric performance. A surface treatment, applied since 2005, gives the Parachrom hairspring its blue colour and further improves the regularity of its pulsations over time.

Paraflex

An optimised shock absorber developed and patented by Rolex to protect the movement’s core components against sudden shocks. Compared to standard shock absorbers in watch movements, the Paraflex is up to 50 per cent more robust and resistant, enabling the movement to withstand demanding conditions and shocks, while ensuring uninterrupted chronometric precision.

Perpetual (Rotor)

Self-winding mechanism with a free rotor, developed and patented by Rolex in 1931. It consists of an oscillating weight that rotates in both directions under the impetus of the wearer’s wrist. In doing so, it winds the mainspring, which provides the movement with its source of energy.

R

R

Ring Command

System of interaction between the case and movement developed and patented by Rolex for easy selection and adjustment of particular functions via a rotatable bezel and the winding crown. On the Yacht-Master II, it affords access to the programming function of this regatta chronograph’s mechanical countdown. On the Sky-Dweller, it allows easy selection of the functions to set: date, month, local time and reference time.

Rolesor

A term patented by Rolex in 1933, Rolesor refers to the combination of Oystersteel and 18 ct gold in its watches. Featured on Rolex models since the early 1930s, Rolesor is a true Rolex signature as well as a prominent pillar of the Oyster Perpetual collection. It is a harmonious combination of gold that is coveted for its lustre and nobility, and Oystersteel which reinforces strength and reliability.

Rolex Bracelet

The iconic band that comfortably secures a Rolex to the wrist. It comes in distinctive Oyster, Jubilee, Pearlmaster or President styles. Characterised by the solid-link construction for uncompromising strength, the patented Easylink system effortlessly extends the length for added comfort to achieve the perfect balance between elegance, function and reliability.

Rolex Glidelock

Bracelet extension system developed and patented by Rolex. Featuring a rack integrated into the clasp, it enables fine-increment adjustment of the bracelet length. The Rolex Glidelock equips the Oyster bracelet fitted on the Submariner, Submariner Date, Sea-Dweller and Rolex Deepsea divers’ watches, either with a fixed rack under the clasp cover or, for the Rolex Deepsea, a lift-up version that allows the bracelet to be adjusted without removing the watch from the wrist. The Yacht-Master 40, Yacht-Master 42 and Sky-Dweller models fitted with an Oysterflex bracelet, are also equipped with the Rolex Glidelock.

S

S

Saros

Annual calendar system developed by Rolex. Its patented mechanism automatically differentiates between 30-day and 31-day months. This calendar feature, which equips the Sky-Dweller, requires only one date adjustment per year as February changes to March – February having only 28 or 29 days – and thus displays the correct date throughout the year.

Superlative Chronometer

The Superlative Chronometer certification, featuring quality standards that were redefined in 2015, is particular to Rolex. It now applies to a fully assembled watch, after casing the movement, and is a guarantee of superlative performance on the wrist in terms of precision, power reserve, waterproofness and self-winding efficiency. All Rolex watches are covered by the new Superlative Chronometer certification, a status symbolised by the Rolex green seal and coupled with an international five-year guarantee.

Syloxi

A silicon hairspring developed and manufactured by Rolex. Carrying several patents, the Syloxi hairspring is insensitive to magnetic fields and offers great stability when exposed to temperature fluctuations, as well as up to 10 times greater precision than a traditional hairspring in case of shocks. Its performance is based on novel solutions, including optimised geometry and an innovative design of the fixation systems.

T

T

Triplock

Screw-down winding crown with a triple waterproofness system developed by Rolex to enhance the water resistance of its divers’ watches, which is also now fitted on a number of Professional models. The Triplock system is identified by three dots (with sizes that differ depending on the material of the crown) below the Rolex emblem on the face of the winding crown. The Triplock system ensures waterproofness to a depth ranging from 100 to 3,900 metres (300 to 12,800 feet) depending on the case.

Twinlock

Screw-down winding crown with a double waterproofness system developed by Rolex. It ensures waterproofness to a depth of 100 metres (330 feet). Depending on the material of the crown, the Twinlock system is identified by one dot, two dots or a line below the Rolex emblem on the face of the winding crown.

GLOSSARY OF WATCH TERMINOLOGY AND PARTS

A to Z guide to the most important terms used in watchmaking.

Navigating the wonderful and expansive world of timepieces is a breeze once you get used to the specialised vocabulary commonly used to describe watches and watchmaking. To make things even easier for you, here is a specially curated list of horological terminology that you will encounter in your appreciation of Rolex and Tudor watches.

A

A

Auto-Adjustable Clasp

A self-adjusting clasp system developed by Tudor and featured on the Pelagos dive watch. Perfect for deep dives, it is an intelligent, spring-loaded mechanism that automatically causes the watch’s bracelet to contract during higher compression at greater depths and expand as the pressure decreases when the diver ascends to the surface.

B

B

Big Crown

In 1958, Tudor introduced the Reference 7924 Submariner, which was nicknamed ‘Big Crown’ due to its large and distinctive winding crown. While that model has long been discontinued, the trademark component continues to feature in Tudor’s modern day Black Bay dive watch collection. (See also: ‘Crown’.)

H

H

Hybrid-Leather Strap

Paired with Tudor watches, the hybrid-leather watch strap comprises a top leather surface with rubber lining, offering the comfort of a rubber strap with the look of leather. Crafted with attention to detail, the straps feature Tudor’s signature ‘Snowflake’ hand motif.

M

M

METAS Certification

A third-party quality assurance certification by the Swiss Federal Institute of Metrology (METAS). Watches submitted for METAS certification must first be COSC-certified. They are then tested for key functional characteristics including precision, resistance to magnetic fields, waterproofness and power reserve. METAS-certified watches are known as Master Chronometers and they boast outstanding performance ratings including 0/+5 seconds daily accuracy, 200m waterproofness, at least 70-hour power reserve, and magnetic resistance to 15,000 gauss. An example of a Master Chronometer with METAS certification is Tudor’s new Black Bay Ceramic, launched in 2021.

R

R

Riveted Bracelet

A style of bracelet developed by Tudor in the 1950s, where the links are attached to each other with the help of rivet heads at the side of the links. Riveted bracelets are now a mainstay of Tudor’s Black Bay watches, endowing the timepieces with both robustness and signature style.

S

S

Snowflake Hands

Introduced in 1969 on the Tudor Submariner References 7016 and 7021, the ‘snowflake’ hour hand is recognised by its thick, angular tip resembling its nickname. Designed to enhance legibility on the dive watches, the snowflake hand is now a signature Tudor design and features on the brand’s Black Bay and Pelagos watches.

T

T

T-Fit

Tudor’s proprietary rapid bracelet adjustment system, the T-Fit lets the wearer adjust the bracelet’s length in five positions of up to 8mm in total, without the need for tools. A recent innovation, the T-Fit debuted in the new Black Bay Fifty-Eight Bronze.