Brass Single-End Clock Key

(28 reviews)

$10.00

Brass Single-End Clock Key

Single end brass clock key to wind up a wall or mantle mechanical clock movement. See instructions on the top tabs for how to get the right size key for your clock.

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CK4: $10.00
Clock Keys and Cranks- Use our clock key chart to figure out the exact fit for the clock. We offer keys and grandfather clock cranks.
Clock KeysFinding the right clock keyDouble End Clock Key (F / S at 12) NoteThe clock key chart
Please view these information tabs to help with determining the proper key size for your clock.

Mechanical clock keys

Mechanical clock keys is the clock part that is most frequently lost. Once the clock key is separated from the clock it always seems to end up missing. With the below information and the clock key size chart a key can be ordered.

Getting the right one

We have mechanical clock keys in all the sizes available. Between the key chart or by movement type information below, the chances are good of getting the perfect key. The movement type includes if the clock is made in Germany or USA and when it was made. This is the fastest and most easiest way to get the clock key. The further back in time we go with clocks the more the key chart would need to be used instead. The country of origin would be marked on the back plate of the movement and this can help us get the key.

Keys for German units post WW2

German made post WW2 movements that are square or rectangle will take a number 8 keys or crank. If the clock movement is round and made in Germany the key size is number 4. Some round ones are supposed to take a number 3 but if getting 4 it will still fit and wind the clock either way.

Keys for USA units 1900 - 1950

American clocks made from around 1875 until after the second war almost always take the size 7 clock key. The number 7 keys fits the 8 day time / strike units pretty much every time and this is what USA made the most of. This rule may not apply to Westminster (3 places to wind) or time only (one place to wind) clock movements.

Keys for Korean and Chinese clocks

Size 7 for these units usually. All the 31 day clocks with Asian movements and also US replicas made in India, all take size 7.

The over wound myth

Of course any clock that is not working will be wound all the way up from trying to make it run. Everyone winds it up and the clock does not work so the non working clock is always wound up. The only way a clock can be over wound is if its been wound up for so long that the mainspring stuck. When the mainspring is stuck together to itself with rust and goo for so long it may stick that way. This is rarely the situation and usually the clock would have rust on it if the mainspring is so wound up it will not wind down.

The content of this website is copyright by Clockworks and written by James Stoudenmire in year 2020

Double-End Clock-Key F-S Note

The following is a Double-End Clock-Key F-S Note that will be very handy. Some clocks have a small place that looks like a mini clock winding arbor at the 12. It may say F/S or A/R. The F/S represents fast or slow, and the A/R represents advance or retard. This controls the timing of the clock and turning it to fast or advance makes time faster and the opposite for slow. An ideal double end key fits both the winding arbor to wind the clock and also fits the smaller time regulator aspect. This is not easy to get and at the same time is the most lost part. It is possible to regulate the clock another way with an adjustable bob instead of a fixed length bob.

Get the double end key the hard way

Using the clock key size chart, get the right size that the clock requires. This chart works for both the fast/slow regulator and also to wind the clock. However, this is not easy because it requires a measurement of the post the double end key fits onto. In order to get this measurement remove the clock movement or the dial. Without access to the front of the movement it is hard to measure exactly how wide the arbors are that the key is to go on.

Double end clock key the easy way

There are many sizes and combinations for the double end key and it may be tricky to get the right size. Sometimes it is best to just get the 4 pack of double end keys we offer. This is the top 4 most common double end clock keys that are used so the odds are one will be the correct key. Ideally this will supply the clock with a key that fits both the F/S regulator and the winders. However be aware this 4 pack does not guarantee one will work.

Double-End Clock Key F-S Note Continued - An alternate method

It is possible to forget the whole double end key game and use a single end key instead. It does make things easier and is a better long term solution. Inevitably, once the perfect fit the key will get lost again. This seems to be the trend of what happens. Once the key is separate from the clock, there is a higher chance of it getting lost. Many times we suggest putting the key in the bottom of the clock case for safe keeping

Using an adjustable bob instead

The solution to the double end key problems is to get the single end key to wind the clock. Also get the adjustable bob. The adjustable bob can be regulate the clock with the pendulum instead. The bob will have a nut on the bottom. Raise the bob on the pendulum to speed up time. The opposite is true for slowing time down. Once regulating the clock, it will stay this way for the most part. Some timing may or may not need to be done when the temperature changes vastly. For the most part, time the clock and it will stay that way within a couple of minutes a day all year long. The adjustable pendulum bob comes in three sizes, or bob diameters. The middle or smaller diameter bob is fine for most clocks because the weight is not as important as the length.

Parts available to purchase

Other parts to consider besides the double end clock keys. We have two styles of the adjustable pendulum bobs. One of them is the three sizes of bobs that have the nut underneath. We call this the Adjustable Mantle Clock Bob. There is another style bob that is adjustable from the back side. We just call it the Adjustable Antique Style Mantle Clock Bob. They both function the same, it has a bob on the pendulum that can regulate the time. The part they hang onto is usually a long wire with flex spring steel on the top. This gets bent and cut into shape for the desired length. It comes in a three pack and we call them the Long Suspension Spring Rods.

The content of this website is copyright by Clockworks and written by James Stoudenmire in year 2020

Clock key size chart explanation

Clock keys have there own number system from 000 to 16 as seen in the Clock key size chart. However the number does not indicate what size is what number and can be confusing. It would make more sense if the key size was the MM of how wide the key was to fit, but this is not how it works. This section is to figure out what key number to order so the clock can be wound up. Subsequently, the clock key gets lost the most out of any other clock part. Of course, it can be tricky to find the right key for your clock because there are many sizes. The Clock key size chart will give us the right size key to order.

Double end clock keys

In addition, some keys have two sizes on one key and this is called a double end key. By and large, the clock key size chart will work for both the wind up part of the clock and also the smaller F / S portion. When the clock has a F / S regulator portion it will be at the 12 o'clock on the dial.

Alternately, if there is a small arbor inside of a hole at 12, this is the time regulator control and the key would have two ends. Thus, it may say F / S at this location or A / R. F / S stands for Fast or Slow, or it could say A / R to stand for Advance or Retard and is referring to the timing of the clock. Of course, if the clock is running fast in time, turn more to the Slow or Retard direction to slow it down. Refer to the Clock key size chart with your measurements to find a key to work with this function.

Getting the right Clock key size

Given these points, to get the key needed, measure the shaft the key is to go on to, then use the Clock key size chart to get the key size needed. Please do not call asking what key the clock needs, as you will be told it would still have to be measured. In short, measure the shaft that the key goes onto in MM and then use the clock key size chart to match it up.

The lazy way instead of the Clock key size chart

The Clock key size chart has all of the sizes listed however sometimes certain key sizes are known. Generally speaking, almost all post 1960 mechanical clocks, made in Germany take a size #8 key or crank, unless the movement is round. Ordinarily the round ones take a number 4. The American time strike antique units mostly take the size 7 key. Match your measurements to the Clock key size chart to be sure.

  • 1.75mm = 000 Key
  • 2.0mm = 00 Key
  • 2.25mm = 0 Key
  • 2.5mm = 1 Key
  • 2.75mm = 2 Key
  • 3.0mm = 3 Key
  • 3.25mm = 4 Key
  • 3.5mm = 5 Key
  • 3.75mm = 6 Key
  • 4.0mm = 7 Key
  • 4.25mm = 8 Key
  • 4.5mm = 9 Key
  • 4.75mm = 10 Key
  • 5.00mm = 11 Key
  • 5.25mm = 12 Key
  • 5.5mm = 13 Key
  • 5.75mm = 14 Key
  • 6.0mm = 15 Key
The content of this website is copyright by Clockworks and written by James Stoudenmire in year 2020

Clock key size chart explanation

Clock keys have there own number system from 000 to 16 as seen in the Clock key size chart. However the number does not indicate what size is what number and can be confusing. It would make more sense if the key size was the MM of how wide the key was to fit, but this is not how it works. This section is to figure out what key number to order so the clock can be wound up. Subsequently, the clock key gets lost the most out of any other clock part. Of course, it can be tricky to find the right key for your clock because there are many sizes. The Clock key size chart will give us the right size key to order.

Double end clock keys

In addition, some keys have two sizes on one key and this is called a double end key. By and large, the clock key size chart will work for both the wind up part of the clock and also the smaller F / S portion. When the clock has a F / S regulator portion it will be at the 12 o'clock on the dial.

Alternately, if there is a small arbor inside of a hole at 12, this is the time regulator control and the key would have two ends. Thus, it may say F / S at this location or A / R. F / S stands for Fast or Slow, or it could say A / R to stand for Advance or Retard and is referring to the timing of the clock. Of course, if the clock is running fast in time, turn more to the Slow or Retard direction to slow it down. Refer to the Clock key size chart with your measurements to find a key to work with this function.

Getting the right Clock key size

Given these points, to get the key needed, measure the shaft the key is to go on to, then use the Clock key size chart to get the key size needed. Please do not call asking what key the clock needs, as you will be told it would still have to be measured. In short, measure the shaft that the key goes onto in MM and then use the clock key size chart to match it up.

The lazy way instead of the Clock key size chart

The Clock key size chart has all of the sizes listed however sometimes certain key sizes are known. Generally speaking, almost all post 1960 mechanical clocks, made in Germany take a size #8 key or crank, unless the movement is round. Ordinarily the round ones take a number 4. The American time strike antique units mostly take the size 7 key. Match your measurements to the Clock key size chart to be sure.

  • 1.75mm = 000 Key
  • 2.0mm = 00 Key
  • 2.25mm = 0 Key
  • 2.5mm = 1 Key
  • 2.75mm = 2 Key
  • 3.0mm = 3 Key
  • 3.25mm = 4 Key
  • 3.5mm = 5 Key
  • 3.75mm = 6 Key
  • 4.0mm = 7 Key
  • 4.25mm = 8 Key
  • 4.5mm = 9 Key
  • 4.75mm = 10 Key
  • 5.00mm = 11 Key
  • 5.25mm = 12 Key
  • 5.5mm = 13 Key
  • 5.75mm = 14 Key
  • 6.0mm = 15 Key
The content of this website is copyright by Clockworks and written by James Stoudenmire in year 2020

Brass Single-End Clock Key

Single end brass clock key to wind up a wall or mantle mechanical clock movement. See instructions on the top tabs for how to get the right size key for your clock. Most post 1960 mechanical clocks, made in Germany, take a size #8 key or crank. This is for the most part always true with the exception of round movements, these take size 4.

Additional information

Weight 0.1 lbs
Size

Size 000, Size 00, Size 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

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william allen
william allen
1 year ago

i HAVE A wALTHAM 31 DAY CHIME TEMPUS FUGIT CLOCK AND THE WIND UP KEY IS MISSING, dO YOU HAVE ONE AND IF SO WHAT IS THE PRICE,

Alexa Conway
Alexa Conway
1 year ago

My clock is German, wall clock. The original key is brass and says “Swiss 10”. It has 2 holes, no clue how to measure the shaft. Chimes hour and half hour, wind it weekly. Inherited the clock. My parents bought the clock in Black Forest area in early 60’s. The original brass key just ‘blew open’ and is splayed now. the hole is round but the shaft is 4 sided. I have no idea how to proceed.

alexa
alexa
1 year ago

I very much appreciate your response but unfortunately, in my 70’s, I don’t really understand it. ’round movements’ does that mean the face of the clock? Did you receive the photos I enclosed? I don’t know how to measure the ‘shaft’ because my key just ‘exploded’ somehow on the end so it can’t go inside to let me know the depth. I cannot read a tape measure anymore (accident). I hate to be an additional bother but I dearly love this family clock and hope to be able to wind it again.

Alexa Conway
Alexa Conway
1 year ago

posted yesterday. gone. I have a German wall clock, chimes hour and half hour, 2 winding areas. The original key is brass and is stamped “Swiss Made 10”. So, I found a ’10’ and it’s too big. The original key somehow just blew apart, splayed on the bottom. The clock was purchased in Germany in the early 60’s by my parents. Any help? Any hope? I’m heartsick to think the clock could be damaged. I don’t understand the ‘measure the shaft’ info because I would think the shaft is inside the hole…. ? I’m in my 70’s so not great at things like this. thx for any assistance.

Alanna
Alanna
1 year ago

I have a Schaltz Diamond face glass and brass dome clock. What size key would this require?.
I’m not sure of year it was built but was a wedding present to my parents over 60 years ago

Judy
Judy
1 year ago

I have an Ansonia 1882 mantle clock made in NY…What key do I need and where do I get one?

Michael Garcia
Michael Garcia
1 year ago

school regulator A clock key. What size do I need?

Mary Postma
Mary Postma
1 year ago

I have a seth thomas model E704-005 with a A206-004 movement. I need a replacement key what size key do I need

Sam Barbagallo
Sam Barbagallo
1 year ago

BRASS SINGLE-END CLOCK KEY FOR 1950’s ADVERTISING CLOCK

Sam Barbagallo
Sam Barbagallo
1 year ago

HI THERE, I HAVE A 1950’S ADVERTISING CLOCK. IT IS A WIND UP FROM TE BOTTOM OFTHE FRONT FACE OF THE CLOCK. I BELIEVE IT TAKES A BRASS SINGE -END CLOCK KEY, HOWEVER THE ORIGINAL KEY IS MISSING.
WHAT SIZE REPLACEMENT KEY DOES IT REQUIRE?

Michael Garcia
Michael Garcia
1 year ago

Hi I have a 31day school clock regulator A. I need a key for it. What do you recommend? Thank you Michael

Pamela K. Payton
Pamela K. Payton
1 year ago
Rating :
     

I have a D & A Curio cabinet clock that I am trying to get a replacement Key for, but I do not know what size it takes! Can you help? Thank you

Lydia King
Lydia King
1 year ago

I have a 1968I Seth Thomas Golden Rule Wall Clock with two model tags – E477-008 and E477-001, and a keywind movement number, A020-000. The clock was made in the USA. Is a #8 the appropriate size for the square shaft?

Lydia King
Lydia King
1 year ago
Reply to  Lydia King

Sorry, I meant 1968 Seth Thomas Wall Clock.

Lydia King
Lydia King
1 year ago

Thank you.

Paul
Paul
1 year ago

I have a Schatz Royal Mariner 8 Bells clock, 6 1/2″ case. The winding post is square, and measures 3/16″ across. Which key should I order?
Thanks very much.

Paul
Paul
1 year ago

Thank you very much. I found your key chart, and it indicated that for a 3/16″ post (4.75 mm) I need a size 10 key. Am I reading the chart correctly?

Frank
Frank
1 year ago

I have a seth thomas mantal clock Helmsman # e537-001. i deen a key for it do you have any

Eric Parker
Eric Parker
1 year ago

Hi! I have an antique Sessions pendulum wall clock (my Mom calls it an “old-timey store clock that sat over a pickle barrel”)with a glass door. I broke the key and need another one. I can’t seem able to access your chart. Any advice?

Richard Hood
Richard Hood
1 year ago

I have an Elgin shool house 31 day clock.What size key do I need to wind the clock?

Debbie Meers
9 months ago

I have a Seth Thomas Legacy 3 W Cat 1314 I need a wind key…..do you know what size it takes?

waldner41
waldner41
8 months ago

I have a Kassel 31 day clock need a key. What size do I need.

SHERI HARVEY
SHERI HARVEY
7 months ago

I HAVE A WINDSOR (TEMPUS FIGUT) GRANDFATHER (FLOOR MODEL) CLOCK THAT NEEDS A KEY. IT WAS SILVER & HAD A SQUARE END, W/2 WIND UP SLOTS, ONE ON EACH SIDE OF FACE OF CLOCK. IT RINGS ON THE HR. & HALF HR. IT HAS BEEN RUNNING BUT NOT CHIMING. WE MOVED ONCE & CLOCK WORKED FINE….2ND. MOVE THE CLOCK WOULD NOT RUN, 3RD. MOVE CLOCK BEGAN TO RUN BUT LIKE I MENTIONED DOESN’T CHIME. DURING THS LAST MOVE THE KEY WAS LOST…THUS I’M LOOKING FOR A NEW KEY. CAN ANYONE HELP? WHERE CAN I FIND THE CHART FOR KEY MEASUREMENTS? AND SHOULD I BUY A KEY & IT DOESN’T FIT, IS IT RTURNABLE SO I CAN OEDERR SOMETHING ELSE. TX.

Paul
Paul
6 months ago

Do you know the size for a Smith Enfield mantle clock with two holes? I used a key that has ‘5’ stamped on it and it is a little too small.

April14
April14
6 months ago

Hi, I have a vintage MAJAK Russian Crystal Mantel Clock with Bakelite base. I would like to order one your website but I am not sure regarding which key size…Can you help. Thanks.

john eisenlohr
6 months ago

i have lost the key for my seth thomas helmsman e537-001a what size key do i need to buy

john leonard eisenlohr
6 months ago

i have a seth thomas helmsman clock lost key were can i buy one and what size do i need

Anthony Pollock
Anthony Pollock
6 months ago

Franklin Mint reproduction Thomas Jefferson Grandfather Clock key

Charlene Obara
Charlene Obara
3 months ago

I have a vintage Syroco Starburst clock. What size key do I need?

Marc Johnson
Marc Johnson
2 months ago

Someone lost the key to my Ridgeway Grandfather clock. I have the serial number of the clock and it appears to have been made in 1982. How do I determine the proper key to purchase ?

Stewart Waller
Stewart Waller
1 month ago

Hello! I have a Soviet Vostok submarine wall clock with a missing key. Can you help me?

Hung le
Hung le
1 month ago

Size key clock schatz 53

Kathi Sherrill
Kathi Sherrill
1 month ago

I have a beautiful mantle clock my father made me in the early 90’s. I have lost the wind up key. Is it replaceable?