351 Hermle Clock MovementTabs

October 29, 2019 8:29 pm Published by Leave your thoughts
Hermle Clock Movement 350/351MVT NotesHermle IDTiming A BalanceWhat Happened?Why New?Other Names Used

Please view these information tabs to learn more about the 351-020 and other Hermle Clock Movement 350/351 units

Hermle clock 351 - 350 movement

Hermle clock 351 - 350 movement is a popular movement for the bracket style shelf mantle clock. Its basically the same clock movement as the 341 series except the plate size is 20mm bigger. Such as the 341-020 compared to the 351-020. Or the 340-020 compared to the 350-020 are the same unit, but the plate size. The 351 and 350 has larger outer plates overall. However they are not cross compatible because the winding arbors are not quite the same. So the dial on one will not fit a the other movement.

The movement

The 351 - 350 movement Hermle clock series has Westminster chime and with a 120mm square outer plate size. It comes in a pendulum version such as the 351-020 or the non pendulum balance wheel version like the 350-020. The balance kind just has a balance wheel more like a watch on the top of the movement that acts as the escapement.

This is beneficial in that it cant be out of beat and its fine to be off level. Also to move from here to there with no reset up of the clock. All of these Hermle clock 351 - 350 movements take a key size 8 to wind them up and the run time is 8 days in a single wind. These units are all spring driven with the exception being the 351-830 and 351-850. Those units are special as they have two springs and one weight for the center. Often the center weight will be split into two weights on a yoke.

The hammers

The hammer locations are variable on this series. The 5 hammer bottom strike 351-020 pendulum, or 350-020 balance units are the most used, the movement does not take much depth and so it can be put into a shallow clock case no problem. Same with the side strike 5 hammer units like the 351-030, it fits into a shallow depth well. Other hammer locations are the back 4 on one side and 4 on the other like the 351-050 unit. Then lastly as in the 351-060 unit you can have 5 hammers diagonally on the back instead.

The chime

This is a Westminster chime unit. What this means is it will play Westminster progressively as it runs through the quarter hours. On the top of the hour we get to celebrate with the entire song and then it will strike out whatever hour it is.

Placing an order

The movement come as the movement itself with its hand nut, comes with the suspension spring and leader if its the pendulum style Hermle clock 351 - 350 movement. The movement will come already oiled and ready to go. It will come with instructions by email, if you get stuck you can just ask us to help if you have issues beyond the instructions. This family has been working on clocks for literally 100 years, if you have a question, just ask us! And it does not matter if the clock movement is out of warranty either, even years after it does not matter. The factory warranty on this unit is 3 years.

  • Less cost than a cleaning in most cases
  • Should last 25-30 years, a repair would not
  • Easy to install, we can help if needed
  • Ships same day as order
Hermle Clock Movement 351

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Hermle Clock Movement Identification

Identification is done with the numbers on the back plate of the Hermle clock movement. Not from the manual that came with the clock, and not off the wood case. On the back plate of the clock movement you will see the numbers such as 451-050 94cm. These numbers let us know everything we need to know about the mechanical clock movement itself. This tells us if its weight driven, the plate size, and every other aspect of the movement.

When the numbers are matched, the new movement can be ordered. The new movement will be the exact same and not a knock off. Therefore all of your existing clock components will fit just the same a it did.

As discussed in a different section, the new movement is the way to go without a doubt. The new unit is a fraction of the price of an overhaul on the old one. You will have the clock back and running in the shortest time instead of waiting months and sometimes years for the overhaul to be completed. The movement will last another 30 years without much complaint, you cant say this about an old one that was restored.

- - The content of this web page and web site was written and copyright by James Stoudenmire of Clockworks.com - It may not be used commercially without permission. - -

Timing a balance clock movement

Balance Clock Movement Timing is done fairly easy. There are three types clock balance movement styles used after 1950. This section is for those balance units that do not have a platform escapement. The platform escapement can be read about in another section. These notes are only for the larger balance wheel in the top center of the clock movement. This was used by Urgos 6/ series and many of the Hermle clock movements. Such as 340-020 and 350-020. Out of these you have two styles, the old style and then the new style. The old style was used all through the 70's and 80's and 90's. Around this time that they switched to the new style on the Hermle units and by this time the Urgos units were out of production.

The old style

The old style is one with a round spring that goes up and down (Vertical). It goes in a circle around the center arbor of the balance wheel. In this style there is a slide arm with a tiny weight on the balance wheel itself. There is a + and - on the wheel. To speed up time go towards the plus sign. However this style is not always easy to regulate and can be very hard to get it perfect. The factory has special devices to make it perfect. However it’s not that easy on the customer end with this style balance. For this reason it has been improved upon during future manufacturing.

If you have the old style balance then your clock movement has some age to it. If this is the situation you may want to replace the unit anyway. We have the movement brand new with the new style balance for less than the cost of a cleaning. Your clock movement has lasted you 25 years or more. In theory the new unit should last more than this with the improved aspects.

The new style

The units offered on this page all have the new and improved balance assemblies. Despite the change on the balance, these units are a direct fit and will install in the clock case the exact same way as the old unit. If the numbers match from the old unit to the numbers offered on this page, than the movement will be the exact same. It will be the same as it is now but brand new and with the improved balance.

The improved upon balance units have a different kind of hairspring (Horizontal). It will also have a screw to regulate it rather than a slider arm. The regulator screw is on the back of the movement near the balance. There is a + and - sign next to it meaning fast or slow. If the clock needs to be faster to keep time then the screw would be turned to the plus and opposite for slowing time.

Hermle clock movement exploded view

- - The content of this web page and web site was written and copyright by James Stoudenmire of Clockworks.com - It may not be used commercially without permission. - -

Mechanical Clock Movement Issues

Mechanical Clock Movement Issues arise after years go by because the oil turns solid. With age, the mechanical clock movement's oil solidifies and becomes black and sticky. By the time 20 or 30 years go by, the oil has solidified and is creating wear on the movements brass plates.

If you look at your old clock movement, you will see holes in the brass plates where there are small pivot arbors sticking into these holes. These pivots are what the gears of the clock ride upon and as the pivots spin in the solidified oil, this makes the holes oblong instead of round. With the pivot holes oblong, the holes are pinching the pivots and creating resistance in the gear train. With the solidified oil and the pinched pivots, the clock will eventually stop working or chiming.

This wear takes place in the holes that are in the brass plates and is hard to identify sometimes. These holes in the brass plates become oblong instead of round and this pinches the pivot arbor going into it. Between this, and the solid oil, the clock ceases to function. To have this repaired is an expensive and long process. To have a mechanical movement serviced can cost two times as much or even three times the amount of the new one.

- - The content of this web page and web site was written and copyright by James Stoudenmire of Clockworks.com - It may not be used commercially without permission. - -

New Mechanical Movement Reasons

New Mechanical Movement Reasons to get the new one when we can just repair the old one? The reason is because it is still in production. Its still made in mass production in Germany, so this means its available for a lot less cost. Even the best repair job from the best repair professional, cannot make it as good as a new one.

New Mechanical Movement Reasons are because it can ship from USA the same day you order it. The time it takes you to get you're clock up and running is very short. A repair can usually take months and then you are still left with a used overhauled movement rather than a new one.

When you receive a new movement it is the same as you're old movement. All clock component parts such as weights will fit on to the new movement. The cost of a new movement is less and when it's installed it should last another 25-30 years without intense service. Over the years, if there is improvements that can be done on the movement, the factory updates them. We here at Clockworks offer only the highest grade mechanical clock movements and they come with a 2 year warranty.


The new unit will cost less and ship now. It will be far better in every way than getting the old one restored. You will have a new movement in days instead of the used one back in months.

- - The content of this web page and web site was written and copyright by James Stoudenmire of Clockworks.com - It may not be used commercially without permission. - -

Hermle Clock Movement Aliases

Hermle produced clock movements and used aliases for names in a way. The movement could be stamped many names but really it will be made by Hermle. Some companies bought so many they were able to get there name on the movement instead of Hermle. The following is only a partial list of names that could be on the clock movement.

The best disguised Aliases

Seth Thomas also Mason and Sullivan had not only there name, also there own internal numbering system. This was stamped on the movement, instead of the Hermle number. Since it is not a Hermle number, the number would need to be converted to what the real number is . This is done with the Mason and Sullivan chart, or the Seth Thomas conversion Chart. However the Seth Thomas chart is not very accurate, please see instructions on that page.

It is best to replace the clock movement if either of these names are on the movement automatically. You do not have to think and decide if repair is better, the answer is a simple no. These companies went out of business long ago and the unit is over its lifetime. The lifetime is 25 - 30 years before it needs an overhaul or replacement. Both ST and Mason Sullivan on the movement would indicate the clock is about 40 years old.

The other Hermle Clock Movement Aliases are easy

Hermle Clock Movement Aliases on other clocks used only their name, and not there own internal numbering system on the Hermle movements. So basically if the clock is of post war German origin you can just look at the number and forget the name. The numbers will indicate what movement it is. If it is a Hermle movement its 3 or 4 digits followed by a hyphen, and then 3 more digits. Like this 1161-853 or 340-020 or 351-060. If the numbers look like this it is made by Hermle.

Other Names Used

  • Hamilton
  • S. Larose
  • Mason & Sullivan
  • Welby
  • Pearl
  • Tally Industries
  • Bulova
  • Seth Thomas
  • Howard Miller
  • Sligh

Hermle Number Examples

Below are some typical examples of the Hermle clock movement numbering system. If your clock numbers are similar to this, its made by Hermle.

  • 451-050 94cm
  • 340-020
  • 140-070
  • 451-030 66cm
  • 341-020 45cm
  • 1151-050 114cm
  • 451-053 94cm
  • 1161-853 114cm
  • 141-070 45cm
  • 351-050 55cm
  • 1161-850 94cm
  • 241-070 94cm

Hermle Clock Movement

The numbers on the back plate of the 350 or 351 Hermle Clock Movement is everything one needs to get a replacement. If the numbers match then the movement will match. So if is says 350 or 351 and the rest of your numbers, it will be the correct one.

Hermle Clock Movement
Assistance = 800-381-7458

Hermle Clock Movement

  • Brand New and Original
  • Westminster Chime
  • Plate size 120 x 120mm
  • Spring Driven
  • Includes Leader
  • A fraction of the price of an overhaul
  • Should last 25-30 years, an overhaul would not
  • Instructions and expert support
  • Hermle Clock Movement of Germany

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