glossary of mechanical terms

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DAN GENDRON’S SIMPLIFIED MECHANICAL WATCH REPAIR FOR PROFIT—AN ILLUSTRATED GUIDE

Glossary A Definition of

Mechanical Watch Terms

NOTE: It is important to your understanding of the procedures in this book that you familiarize yourself with these terms FIRST.

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NOTE: It is important to your understanding of the procedures in this book that you familiarize yourself with these terms FIRST.

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111 TriChlorethylene: AKA hairspring cleaner

Acetone: Strong Solvent

Alloy Main Spring A.K.A. un-breakable main spring

American Illustrated Manual of Watch Movements:

A reference book.

111 Trichlorethylene

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Arbor: the mechanical axis of a moving part. A round

shaft with a hook for the mainspring in the center of the

body.

Aspirator: A.K.A. hand blower

Arbor

Aspirator

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Balance bridge: the bridge that the balance wheel is

suspended from. Also holds the upper balance jewels.

Balance jewels: the hole and cap jewels of the balance

bridge. Also located in the movement plate.

Balance Bridge

Balance Jewel

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Balance seat: the part of a balance staff that has the

rivet that holds the balance wheel to the staff.

Balance staff: The axel that the balance wheel rotates

upon

Balance Seat

Balance Staff

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Balance timing screws: these screws can be used to

adjust the timing of a watch movement. When the

screws are pulled out they slow the escapement by

causing drag, and conversely, screwing them in speeds

up the movement by lessening drag. Also, the same

result can be achieved by adding or removing timing

washers (weights)

Balance Timing Screws

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Balance Untrue: This happens when the balance wheel

is bent. This usually happens after the balance staff has

been replaced by someone who is not gentle.

Balance wheel: the oscillating wheel of a watch that

regulates the timing of a watch.

Banking pins/Guides: the two pins or cut outs in the

movement that limit the angular motion of the pallet.

Balance Wheel

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Barrel: the circular container in which the mainspring is

housed, it has gear teeth around the circumference.

Banking Pins

Barrel

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Barrel arbor: the axis of the barrel around which the

mainspring is wound. It moves independently within

the barrel and connects to the mainspring. (See Arbor)

Barrel bushing: This is the hole in the main spring

barrel that the arbor rotates upon

Barrel cap: This is the cover of the main spring barrel

Barrel Bushing

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Barrel cap bushing: This is the axis that the main

spring arbor rotates in.

Barrel Cap

Barrel Cap Bushing

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Beat: The time difference between the lock action and

slide action of the escapement.

Bench block: a.k.a. anvil, this is a block of steel that

has holes in it, used as a work surface for re-riveting etc.

Bench Tweezers: These are blunt end tweezers that can

be used for common repairs

Bench Block

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Bent pivot: This is when the axis of a pinion becomes

bent.

Bench Tweezers

Bent Pivot

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Black light: a.k.a. Ultra Violet light used for setting

ultraviolet glue.

Bow: the ring of a pocket watch case that is attached to

the pendant, that attaches to the stem tube, and is use to

attach a chain to the watch.

Black Light

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Brace end: A type of mainspring with both a hole and a

t-end.

Bow

Brace-End Mainspring

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Broach: a.k.a. bit, a four or five sided tapered cutter,

used in much the same way that a drill bit is used.

Broken staff: This when the pivot on the balance staff

is broken

Canned air: Self-explanatory.

Cannon pinion: a tube with a pinion at its base

Broaches

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frictioned to the center wheel post. The minute hand

attaches to the cannon pinion.

Canon Pinion Tightener: Miniature Stake & Punch for

tightening canon pinions

Canon Pinion

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Cannon pinion remover: A tool that safely removes

the canon pinion

Canon Pinion Tightener

Canon Pinion Remover

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Cap jewels: This is a flat-faced jewel placed over a hole

jewel, to prevent contaminates from entering the hole

jewel.

Case knife: A knife that has a blunt end for opening

watchcases

Cap Jewels

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Center wheel: the wheel that is located in the center of

the movement. Also known as great wheel.

Case Knife

Center Wheel

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Center wheel post: The metal post that extends from

the center wheel and passes through the movement to

the dial side. The cannon pinion is placed upon it.

Click: A ratchet device use to hold tension on the

ratchet wheel.

Center Wheel Post

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Click Spring: A small circular spring that holds the

click against the ratchet wheel

Click

Click Spring

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Clockwise: this is any circular motion to the right

Clutch lever: This is the lever that moves the clutch

from the wind position to set position. A.K.A. Setting

Lever

Clutch Lever

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Clutch spring: A Spring that maintains the position of

the clutch lever

Clutch wheel: a.k.a. sliding pinion, this pinion has two

parts. The upper part is driven by the wining pinion and

the lower part drives the setting wheels.

Clutch Spring

Clutch Wheel

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Collet: the small brass collar that fits friction-tight on

the balance staff, which connects the hairspring to the

balance wheel.

Compensating balance: AKA Heat Compensation

Balance is a bimetal balance wheel with spaces at

opposite points, which allow the balance to expand and

Collet

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contract with heat and cold, preventing timing errors

caused by temperature.

Conical pivot: A pivot that is cylindrical at one end and

gradually widens toward the arbor shoulder. This form

of pivot is used on arbors, and are made to rest on cap

jewels.

Compensating Balance (for Heat and Cold)

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Conical punch: a punch with a rounded end

Counter-clockwise: Circular motion to the left

Crazy glue: NOT USED!!!

Crown: The winding knob at the end of the stem.

Conical (Rounded End) Punch

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Crown wheel: the winding wheel that makes contact

with the winding pinion and the ratchet wheel.

Cylindrical pivot: a straight pivot.

Daylight bulbs: a.k.a. full spectrum light, these

florescent bulbs emulate actual sunlight, easy on the

eyes.

Crown Wheel

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De-magnetizer: A tool that removes un-wanted

magnetism from watch movements

Dial: The flat surface that rests below the hands, that

has markers or numbers on it.

Dial protection device: A device used to protect the

dial when the hands are installed or removed, usually a

Dial

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thin piece of plastic.

Dial side: The side of the movement that contacts the

dial

Dial screws: These are screws that hold the dial to the

movement, usually located on the side of the movement

Dial Side

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Digital Caliper: A measurement device with a digital

read out.

Dial Screws

Digital Caliper

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Digital timing machine: A machine that counts the

ticks of a watch movement, used to regulate the timing

of a watch. (See Witschi)

Dime store compass: An inexpensive compass used to

determine if there is magnetism in a watch.

Double roller: Called this because the roller table has

two pieces, the actual roller table that has the roller

jewel set in it, and the impulse table below it, which

prevents too much movement in the roller table. Also

known as a safety roller.

“Dime-Store” Compass

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Dryer: A heater used to dry watchcases and movements

eBay: www.ebay.com To find hard to locate tools.

End shake: This is the “Slop” or looseness between two

pivots

Double Roller

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Epoxy: A strong glue, NOT USED!

Escape wheel: The wheel that is driven by the 4th wheel

and is acted upon by the pallet fork.

Escapement: The parts of the escapement are the

escape wheel, Pallet fork, Roller Table and Roller Jewel,

and the Balance wheel. These parts regulate the amount

Escape Wheel

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of time it takes for the train wheels to move, or

“escape”.

Final rinse: The last process in the movement cleaning

process. Also see SOLO LUBE

Flat end punch: A punch that has a flat surface on its

face

Flat Hairspring: This hairspring does not need the

Flat End Punch

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compensation of an over coil.

Fork slot: This is the end of the pallet fork that the

roller jewel rides in.

Fourth wheel: the wheel that drives the escape wheel.

In watches that have a subsidiary second hand it has a

Fork Slot

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long pinion that passes through the dial side of the

movement for the second hand.

Frequency: the number of times that a periodic function

repeats the same sequence of values during a unit

variation of the independent variable. In English: The

Fourth Wheel

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number of ticks per hour.

Gear Train: Comprised of the mainspring barrel, center

wheel, 3rd wheel, & 4th wheel.

Gum Arabic: a.k.a. Radico & Rub-Out. A gum that is

used to remove smudges from surfaces e.g. dials and

movements.

Hairspring: the spring that regulates the amount of time

Gum Arabic

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it takes for the balance wheel to rotate back and forth.

Hairspring cleaner: a.k.a. 111 Trichlorethylene, a fast

drying solvent used to clean hairsprings.

Hairspring stud: the vertical post located at the farthest

Hairspring

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outside point of the hairspring, and attaches to the

balance bridge.

Hairspring tweezers: Very fine point tweezers most

often used to work on hairsprings. Good sizes are 3C,

and 5C’s.

Hairspring Stud

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Hand blower: A rubber bulb blower, used to remove

dust and debris from movement. See Aspirator

Hand removers: a tool used to remove hands

Hands: the moving pointers used to indicate the time.

Hand Removers

Hands—Hour, Minute, Second

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Hardened glass: Often used in more modern watches.

Also know as mineral glass because it has a crystalline

structure, similar to minerals’ crystalline structures.

Hole End: A type of mainspring with a hole at the outer

end that connects to a hook inside the mainspring barrel.

Hole End Mainspring

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Hole Jewel: a jewel that a pinion rests on, usually a

wheel.

Hour wheel: the wheel that fits over the cannon pinion

and to which the hour hand is fastened. The hour wheel

also connects to the minute wheel pinion

Hole Jewels

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Hour wheel washer: A thin washer used between the

hour wheel and the back side of the dial.

Hour Wheel

Hour Wheel Washer

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Inca: a.k.a. shock jewel, a.k.a. Kif Jewel. A thin brass

spring above the cap jewel that acts as a shock absorber

for the pivot.

Indicator: Usually a separate dial on a watch that

indicates something other than time, e.g. Up & Down

Inca Jewel (a.k.a., Incabloc, Kif, Shock Jewel)

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Wind Indicator, Date Indicator etc.

Inserter: The thin metal ring around a new main spring,

that holds the mainspring in place while being inserted

into the mainspring barrel.

Inverto method: This is the Modern method of

removing and installing a balance staff, using a staking

set.

Inserter

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Kif: See Shock Jewel

Knuckle: The joint on your hand

Lancashire Gauge: The American standard

measurement for pocket and wristwatches. 1 size =

1/30th of an inch per size

Lathe: A tool used for turning and cutting metal.

Lathe

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Lignes: the Swiss measuring standard. These are only

used on watches that are not American. 1 ligne = 2.256

mm

Loupe: a necessary visual magnifier. If you don’t have

one, get one! Not the same as a visor

Lower balance jewel: This is the jewel that is set into

the movement plate that the balance staff pivots upon.

Loupe

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Magnetism: Magnetism may get into the steel parts of

the movement, most often the mainspring and

mainspring arbor.

Mainspring: Thin, long strip of steel or alloy made into

a spring, which supplies the power to run the watch.

Lower Balance Jewel

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Mainspring arbor: This is the axle that connects to the

inner end of the main spring and pivots in the main

spring barrel.

Mainspring (in Inserter)

Mainspring Arbor

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Mainspring barrel: Cylinder-shaped, it contains the

mainspring and mainspring arbor and serves as the first

wheel of the gear train.

Mainspring winder: A mechanical device used to re-

wind the main spring so it can be placed into the main

spring barrel.

Micrometer: A caliper used to determine diameters.

Mainspring Winder

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Mineral glass: hardened glass, often used as jewels and

crystals

Minute wheel: the wheel driven by the cannon pinion.

Micrometer

Minute Wheel

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Minute wheel post: a small post mounted into the dial

side of the movement, used as an axel for the minute

wheel

Minute wheel pinion: the pinion on the minute wheel

that drives the hour wheel.

Minute Wheel Post

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Movement holder: a small metal vise for holding the

movement when we are working on it.

Movement Plate: the disk of a watch movement that

forms the foundation of the movement.

Minute Wheel Pinion

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Oil reservoir: this is the recess in a hole jewel setting,

in which to place oil.

Oilers: Device for applying oil.

Movement Plate

Oilers

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Out punch: Part of the inverto system for removing

balance staffs, used with the balance staff remover.

Over banked: This is when the roller jewel gets caught

behind the pallet fork. In this position the balance

cannot move.

Overcoil hairspring: This type of hairspring uses the

last coil of the hairspring as a lever to compensate the

Out Punch

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beat of the escapement. Also known as a “Brequette”

hairspring.

Pallet bridge jewel: The jewel that is in the pallet

bridge that the pallet fork pivots upon.

Pallet Bridge Jewel

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Pallet: The part of the escapement that is between the

roller table and escape wheel.

Pallet jewel: a.k.a. Pallet Stone, two jewels that are

mounted in the pallet fork. These jewels come in contact

with the escape wheel.

Pallet

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Parts tray: Small usually triangular metal trays for

holding parts.

Pallet Jewels

Parts Tray

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Peg wood: Thin stick used for cleaning pivots and

applying glue.

Pendant: the neck on a pocket watch case to which the

bow is attached and the stem passes through.

Peg wood

Pendant

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Pinion: the small gears that mesh with the wheels of the

train. “Pinions push and wheels follow.”

Pith wood: Small lightweight pieces of wood used as a

place to rest a movement when we work on it, also used

to clean parts.

Plastic rinse: A.K.A. Solo Lube, a final rinse of the

cleaning process, it adds a protective surface to the

movement.

Pith Wood

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Poise: a perfect balance condition brought about by the

adjustment of the balance screws in the balance wheel,

to equalize the weight of the balance in all positions.

Poising tool: A tool that the balance can be suspended

on during the truing process

Poising Tool

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Polishing machine: An electric motor with spindles and

cloth wheels used to polish metals

Punch: A tool used with the staking set.

Radico: See Gum Arabic

Ratchet wheel: the wheel with pointed teeth on it

Ratchet Wheel

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circumference, mounted over the mainspring barrel

arbor. It is held from running free by the click, to retain

power in the mainspring.

Regulator: Mounted upon the balance bridge, it has

small pins that the hairspring passes through. Moving

the regulator changes the amount of slack, thereby

changing the timing of the hairspring (making the watch

run faster or slower).

Regulator

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Resilience: The capability of a strained body to recover

its size and shape after deformation, caused especially

by compressive stress. A.k.a. springiness

Reverse threads: You know the old saying, righty

tighty, lefty loosey. These threads go in the opposite

direction. Most often used on crown wheels

Rivet: The friction fitting that holds the wheel to a

pinion

Roller Jewel: the jewel at the base of the balance

assembly, mounted in the roller table.

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Roller table remover: A tool that removes the roller

table from the balance wheel

Roller Jewel

Roller Table Remover—American

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Roller punches: Specialized punch for installing roller

tables.

Scissors Roller Table Remover—Swiss

Roller Table Punch

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Roller table: The part of the balance wheel that the

roller jewel is mounted in.

Roller table pliers: They almost look like heavy

tweezers with rounded slots in them. Used to move the

position of the roller table to bring the escapement into

beat.

Roller Table

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Safety roller: a.k.a. impulse table, a small table set

below the roller table that prevents the balance wheel

from traveling too low and damaging the roller jewel.

See Double Roller

Scissors type roller remover: A knife edged tool for

removing Swiss type roller tables

Roller Table Pliers

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Second hand: The small second hand usually set over

the # 6 on the dial. Not to be confused with a Sweep

Second Hand.

Set position: When the stem is pulled out to set the

hands.

Setting lever: a.k.a. Detent

Setting Lever

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Setting wheel: The wheel or wheels between the clutch

wheel and minute wheel.

Sharpie marker: Used for marking parts and cases.

Setting Wheel

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Shellac: a material that is soft and flows under pressure

when heated but becomes rigid at room temperature.

Now we use GLUE!

Shock Jewel: A jewel with a brass spring over it.

When there is a blunt force applied to the movement the

brass spring jettisons the cap jewel to prevent the pivot

from breaking. Also see Kif and Inca

Sharpie Marker

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Solvent: A solution that dissolves oil and grease.

Staff remover: A tool used with the inverto tool to

remove balance staffs.

Staking set: A set of special purpose punches, with an

Inverto anvil. Used most often for removing and

installing balance staffs.

Staff Remover

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Seitz: Jewelling method using a assortment of hole and

pallet jewels

Seitz gauge: Gauge used to determine the hole size of

Seitz jewels.

Staking Set

Seitz Gauge

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Stumps: Special purpose metal rests for use with the

staking tool.

SoloLube: A plastic rinse used in the final rinse of the

cleaning process.

Stem: The winding part used to set and wind the

movement

Stumps

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Stud bridge screw: The screw that holds the

hairspring stud to the balance bridge.

Sweep second hand: The hand that records seconds, it

is in the center of the dial and passes thought the cannon

Stud Bridge Screw

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pinion.

T-End: A mainspring that has a t-bar brace at the outer

end of the mainspring.

T-End

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Third wheel: The wheel between the center wheel and

the fourth wheel.

Timing machine: Machine used to determine the timing

of the movement, it counts the ticks, too many - too

fast , too few - too slow. See Witschi

Ultrasonic cleaning solution: Solution use for cleaning

movements

Third Wheel

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Ultrasonic watch cleaning machine: Movement

cleaner, with at least two ultrasonic cleaning areas.

Unbreakable main spring: a.k.a. alloy main spring

UV Glue: Glue that dries clear and is very powerful,

must have a ultra violet light source to harden.

Ultrasonic Watch Cleaning Machine

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UV Lamp: a.k.a. black light

W-10 Grease: a.k.a. main spring grease, use for main

springs and setting parts

Watch material supplier: The wholesaler who will sell

you watch parts and tools. See Resource Guide

Watchmaker’s bench: A special purpose bench for

repairing watches

W-10 Grease

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Watchmaker’s hammer: A very small lightweight

hammer

Winding Arbor Tool: Used on American watch

movements. When the movement is out of the case and

has no stem, this tool can be used to wind and set the

watch.

Watchmakers Hammer

Winding Arbor tool

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Winding pinion: A double pinion that the stem passes

through, used to wind and set the watch.

Witschi Watch Expert: Digital Watch Timing Machine.

Witschi Watch Expert

glossary of mechanical terms

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