400 Day Clock Suspension Spring Sizes

A company called Horolovar makes suspension springs for 400 day clocks. Various thicknesses are available. If the spring is too thick the clock will gain time, and if too thin it will lose time

Suspension Spring Thickness for Schatz 400 Day and 1000 Day Clocks

Schatz clocks have a model number inside a circle on the back plate (49, 53, 54 or JUM/7). The other numbers on the back of a Schatz clock are the date code (month and year). Here are the suspension spring thicknesses for Schatz 400 day and 1000 day clocks:

  • Schatz standard size clock (49 on back plate): .004 inch
  • Schatz miniature (53 on back plate): .0023 inch (Note 4-8-12: I now recommend a 0.0024 inch thick spring)
  • Schatz 1000 day clock (54 on back plate): .0024 inch
  • Schatz midget 400 day clock (JUM/7 on back plate): .0022 inch

Suspension Spring Thickness for Kundo 400 Day Clocks

  • Kundo full sized clock (about 12″ tall): .0032 inch
  • Kundo miniature clock (about 9″ tall, including the oval base model): .0023 inch (Note 4-8-12: I now recommend a 0.0024 inch thick spring)
  • Kundo midget (similar to the miniature but the anchor pin has an offset bend and makes contact with the fork slightly behind the back plate): .0022 inch

For other clocks, you will need the Horolovar 400 Day Clock Repair Guide to determine the proper spring thickness. Note: measuring the old spring’s thickness is not a reliable method, as the spring may not be a Horolovar brand spring. The Repair Guide and suspension springs are available from Norkro.com and other clock parts suppliers.

The thicknesses given above are for genuine Horolovar suspension springs, which most clock suppliers sell. You may want to ask to be sure you are getting Horolovar suspension springs.

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  1. I was wondering if anyone could help me with sizing a mainspring for a 400 day Schatz Minature 53. I’m measuring .506 wide, .012 thick, 43″ long. Does this sound correct? Thanks for any help.

  2. The clock is level when the point on the bottom of the pendulum is in the center of the cup on the base. You can use pieces of cardboard under the base (or the small table you are setting the clock on) to level the clock.

  3. Bill, this website is very hard to navigate. I have a general 400-day clock operation question but I can’t find out where to ask it so I’ll ask all my questions here.

    My clock was made in January 1953 and thus does not have the leveling screws as shown in your posted 1959 instruction booklet. How should I check and adjust the level? The clock will sit on either a small 4 leg wood table or on a glass and aluminum etagere that has 4 small feet.

  4. Use a 6789. If the clock doesn’t run well, then lower the fork slightly (about 1/16 inch).

    (The 6789A is used for older ones from the 1930’s and earlier. The difference is that the fork is lower on the wire.)

  5. What is the difference between the Horolovar 6789 and 6789A Suspension units? I have a Schatz Jarhesuhren purchased in Germany 55 years ago. It needs a new suspension unit but some references say to use a 6789 unit and others say to use a 6789A unit. I want as close to OEM as possible.

  6. Hello Bill,I have a Schatz 400 JUM/7. 11/62 with lovely memories of long past mum and dad,and the suspension wire has broken,consequently lost the bottom block.From your info i need a 0.0022″.Whats the price and how can i get it here in Israel

  7. It could be that the fork is “fluttering” – ticking rapidly or making more than one tick per swing of the pendulum. You can verify this by timing 8 rotations of the pendulum with a stop watch – it should take one minute. If this is the case, then raising the fork slightly on the wire will cure it. A .004 suspension spring is correct unless the pendulum is not original. Also, make sure you have turned the regulating nut clockwise to slow down the pendulum.

  8. I have a Schatz (49 4 ball dated 03 53) and used .004 suspension spring. The clock is in “Beat” and has the correct overswing. It has 8 beats per minute. Now, the problem is it runs to fast (15 minutes/hr). I have adjust pendulum as far as possible to slow it down. What spring size should I use to slow it down (.0032 or more?)

  9. Hi Bill, I have a Schatz 400 Day Model No.53; it came to me with the mainspring wound up tight and jammed, so I released the spring (slowly & under control). Then I wound it again, but the clock still won’t run. Suspension wire seems ok, if a very little kinked. Can’t see anything else obviously amiss, and there’s aticker on the base saying it was serviced in ’07. Any ideas? I’d be grateful for your advice. Thanks, Jeff

  10. I’m looking for suspension springs for HERMLE LARGE ANNIVERSARY/400 DAY CLOCK.
    It should be about 140 mm long.

    Thanks a lot!

  11. The tension spring (called the clickspring) that pushes up on the click needs to have its end bent upward so that it once again provides tension. To do this, the ratchet wheel needs to be removed so that there is room to bend the spring upward (towards the ratchet wheel).

  12. My Schatz 400 has been depowered. Now when I attemp to rewind it just turns both ways with out resistance. I seem to not be able to lock in the gear with the lever that hold the tension.


  13. Hi

    My son accidentally broke the three Clock Suspension Springs that holds up my original Ansonia Swinger. They are made of a flexible metal that is blued and appears to be a little wider that the thickness of a dime and measures about .75 inches long.

    Do you know where I can get these Suspension Springs replaced and at whart cost?


  14. Gretchen, I can repair this clock for you. Basic pricing and information is on the following web page:


    Your clock will need an overhaul and a new suspension spring. A replacement pendulum will be about $50 extra (it will be identical to the one the clock originally had).

    Most people have these clocks repaired for their sentimental value, as repair costs typically exceed what the clock could be sold for.

  15. I acquired a Schatz domed clock. On the back right side it says 11 53. Inside a circle on the left backside is 53. There is no pendulum inside the glass dome. The local jeweler said he couldn’t repair it. Said it needed suspension spring & wire and pendulum which he said were impossible to find. Can you help me locate these items? It really is a pretty
    clock with gold ornate hands and gold round face and gold numbers with a tiny strip of black behind the numerals, and around the base. Would the clock be worth trying to fix and give me a ballpark figure if possible.

  16. It’s a very beautiul clock with intact glass globe. I picked it up at a rummage sale for $8. Wow! Thanks very much for your help. I appreciate it very much.

  17. Paul,

    I am pretty sure that this uses the same suspension spring as a regular Kundo standard clock – .0032″. The movement and pendulum are the same – just the case is different (these are beautiful clocks!)

  18. I have a Kundo Louvre model 15 inch anniversary clock. I can find lots of references to 12 inchers and smaller but nothing on this model. I need to replace the suspension spring but don’t know the Horolovar equivalent to order. Can you help? Many thanks in advance.

  19. Dan,

    Thanks for the kind words.

    The only way to know which suspension spring to use (other than for a Schataz or Kundo) is to look it up in the Horolovar 400 Day Clock Repair Guide. This book is full of excellent information on repair and adjustment, and will tell you which suspension spring and mainspring to use for any 400 day clock.

    One interesting thing about repairing 400 day clocks, is that they almost NEVER need bushing. The few that have come into my shop with bushings installed by a previous repairer, would have been better off if they had not been bushed (because the bushings were installed off-center)!

  20. Bill,
    You are a great mentor to alot of us out here and I really appreciate your work and your remarkable web site. Thank you for all you do and for your invaluable experience and expertise.

    I am working on a German 400-Day clock that appears to be nothing more than a bit dirty. The suspension spring looks OK, but if I decide to replace it, can you tell me how to determine what wire to use? I look at the numbers from Timesavers and others, but they do not tell me what number goes with what wire for which clock.

    I do not have the Horolovar book yet and of course will purchase it soon since this is the second 400 day clock I have been asked to repair this month.

  21. Your clock was made by Jahresuhrenfabrik (Year Clock Company). This company later became Aug. Schatz and Sohnne (Schatz). It normally uses a .004 inch thick Horolovar suspension wire.

  22. Can any one help..Ineed spares for my 400 day clock but don’t know the make of the clock The only mark i can see is “A clock face with a rampant elephant on either side”

  23. I have a second hand kundo battery operated anniversary clock. The pendulum does not rotate (except for brief seconds of time). This model has three adjustable “levelers,” and the base is level. What part do I need, and is this something a very beginner can repair?

    Thank you, Beverly.

  24. Hello,

    I can supply this unit for $34 plus $8 shipping and handling ($42 total). You may order from my online payment page:


    In most cases, the unit can be installed without modification. Sometimes the fork needs to be moved up or down slightly. Also you need to be sure that the fork tines are not binding on the anchor pin (the pin that moves back and forth as the clock ticks).


  25. Bill, I am looking for a complete suspension spring assembly for a Schantz Midget 400 day clock,the model is JUM/7 2 58. 2 Jewels. The wire is.0022. With top and bottom blocks and escape arm. Is this available and what is the cost. Are any modifications required,or just install?

    Thanks, F.C. Mertz

  26. bill, i need a suspention spring for an anniversary clock. on the back it reads; GUSTAV BECKET– FRIGORG IN SGAL–MEDAILLE D`OR. HOPE YOU CAN HELP!

  27. Bill, I have a Seth Thomas Anniversay Cock (approx 30 years old.) I need a suspension spring. I’ve ordered one before and a Kundo 65A spring was the perfect replacement. Now I can’t find anyone who can tell me what spring will work since nobody knows what will replace a Kundo 65A spring. Any ideas?

  28. I have acquired a Kundo Anniversary Clock and it is apparent that the suspension wire is broken.
    I can see how the wire is attached to the top but how is the wire attached to the top of the 3 balls that hang and rotate. Is something missing.
    I would be grateful for your help.

  29. cannot find suspension spring size,please can you help.The clock is a kundo(kieninger and osergfell),it stands 7″ high,the only wriring or marks are made in west germany and no(0)jewels “nadjusted”.and finally a number printed with ink stamp 3023. with hope and appriciation d shilton

  30. Dear Bill,
    I have a Kundo 400 day clock with a broken suspension.I cannot find the model number anywhere on the clock and need this. Can y ou give me a clue as to how I can identify the model.


    Geoff Buggins

  31. hi Bill,

    how is the pivot on the back plate of the 400 day clock into which the anchor shaft registers to be used? this appears to be located in an eccentric screw head (at least thats my best guess). I have the Horolovar repair guide but it does not seem to make any mention of this? Not that I intend to fiddle with it, but would be good to know.

  32. Hi Bill,

    Any lead as to where the hand tightened screw on which the top suspension block is suspended might be purchased? This is the one item I have just failied to come across.



  33. i recently purchased a suspensionn unit for my shatz 49 400 day clock. i now realize i need the unid or bridge or whatever it is the thih suspension hangs from. can anyone help part numbers would be great.suspension came from timesavers. bill

  34. I have “The Horolovar 400 Day clock Repair Guide” but it isn’t helping with this question, so can anyone else help? My question is what suspension wire size should I use for a Badische c.1906 30 day “lunar” clock? I’d really appreciate a lead on this one.

  35. Does anyone know of a company that sells the COMPLETE suspension units for Kundo clocks? I already tried to order the part from a company (Shor International) and they took my money and decided to never mail the part. Thought there might be another one out there.

  36. Need suspension wire for a Kundo battery operated Anniversary clock, do you have or know where I can purchase one.
    Please Reply

  37. I recommend that you buy “The Horolovar 400 Day clock Repair Guide”, which has drawings of the suspension units for practically all 400 day clocks. From this, you can see which clocks use which blocks and forks. As far as the common sizes go, the Kundo standard uses the large square bottom block, while the Schatz standard uses the large size rectangular bottom block. The Schatz miniature uses a smaller rectangular block. You can adapt various sizes blocks and forks for use in different clocks, but in my professional repair work I prefer to use the original sizes whenever possible.

  38. Hi Bill,

    I wanted to purchase some top and bottom suspension blocks for the 400 day clock but see that each of these is to be had in 3 sizes which becomes pretty expensive. Kindly let me know if any one of these 3 sizes may be used as standard and home into its slot without any problems regardless of the clock in question. If so that would be great. Also a bit of guidance on which size of fork is most commonly used. Thanks! Have a nice day!!


  39. Francis, unfortunately, I have not been able to find any information about these part numbers. Can anyone help us?

    I do have an old original suspension unit that is labeled “Ref: 46-016” and it is for the Schatz miniature 400 day clock (model number 53 in a circle on the back).

  40. Hi Bill,

    I have a few suspension springs purchased in Germany, however the markings on the covers, reproduced here below are rather confusing; would be helpful if you could shed some light on what they imply, Thanks.

    Pendelfeder fur typen

    1203 – 1239
    Ref: 49-024
    2403 – 2439

    I am a fresher and would appreciate your guidance,



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