Mastering spring bars - Small parts provide great security
A metal part just a few centimetres long that fastens the watch strap to the case...
These are the "spring bars." They are a part that is rarely given much thought, but they are actually the "last line of defense to prevent a watch from falling."
The more expensive the watch, the more the quality of the spring bar will definitely make a difference.
1. What is a spring bar?
A spring bar is a thin metal pipe with a spring at each end that is designed to be "pushed into" the holes in the lugs of a watch case and fixed in place.
- Important parts used for attaching and detaching straps
- The internal spring expands and contracts, catching and securing the lug.
- A common structure that is standard in many watches
If the spring bar breaks, the watch will come off your wrist in an instant.
That's why it's the "most important part even though it's invisible."
2. Types and characteristics of spring bars
① Standard spring bar (Straight Spring Bar)
Most common. Used in many watches.
② Double Flange
Easy to insert tools and easy to replace.
It is also used in some models of OMEGA and Tudor.
③ Reinforced type (Heavy Duty / Fat Spring Bar)
A large diameter model (1.8mm to 2.5mm) used in diver's watches.
It is difficult to come off even during intense movements.
④ No-Shoulder Type
A special type that does not require tools. Common on vintage watches.
⑤ Quick Release
There is a lever on the back of the leather strap, so it can be attached and removed without tools.
Its popularity has skyrocketed in recent years.
⓺Curve Double Flange
This design is often seen on high-end Swiss watches. It pairs perfectly with curved cases, but because the strap also needs to be curved, special tools and strap crafting are required. This can only be done at a watch specialty store.
3. Do spring bars have a “lifespan”?
Yes, spring bars are a consumable part.
■ Causes of deterioration
- Sweat, moisture, and sebum
- Chorus
- metal fatigue
- Deformation due to tool scratches
- Weak internal spring
■ What happens when it deteriorates?
- The spring return becomes weaker
- Does not fit tightly into lug holes
- Worst case scenario: The watch falls.
■ Replacement guideline
From my experience dealing with watches,
We strongly recommend replacing it every 1-2 years .
4. You can never go wrong with the size you choose
The length of spring bars required varies from watch to watch, up to 1mm .
- 19mm lugs → 19mm spring bars
- 20mm lug → 20mm
- 22mm lug → 22mm
However, this does not include curved double flanges (special processing is required to manufacture curved double flanges).
If you use a "short" one...
- It may seem fixed at first glance, but it's actually only partially fixed.
- It comes off with violent movement
- Even luxury watches can fall
On the other hand, "long" things...
- Forcing it in can damage the rug.
- Risk of case deformation
Choosing the right size is safety itself .
5. Why spring bar care is so important for luxury watches
The bent spring bar is a part that costs a few hundred yen,
A lifeline to protect your watch from falling.
The following watches in particular require special attention:
- Divers
- Chronograph
- Gold case
- Vintage
- A watch with a soft leather strap
- Heavy model
The cheapest and most effective way to protect your expensive watch
This is a regular replacement of the spring bars . (Please request this when you replace the strap.)
6. What you can do at Comptoine
CONTÉVANOU, an authorized watch and jewelry dealer, is always available to replace and inspect bend spring bars.
- Correct size measurement
- Compatible with reinforced spring bars for divers
- Quick release compatible
- Rug scratch prevention construction
- Belt replacement and adjustment
- Products purchased from other stores and overseas models are also accepted.
- Battery replacement and overhaul can be performed at the same time
- Compatible with curved double flanges (curved cases)
📍 Accessible from Shinjuku, Yoyogi, and Shibuya 📍 English-speaking / Tax-free
📍 Craftsmen carefully handle even minor repairs
Although it's rare to see them these days, in the early 1960s, 18K gold cases came with 18K spring bars. At the time, it was likely designed with the idea that stainless steel would complement the 18K case. From 2025 to 2026, most manufacturers use thickly plated spring bars. This technology also coats watches with 18K gold plating, preventing interference between the metals. *However, maintenance is still required.
The "invisible parts" are the key to ensuring the safety of your watch. Please feel free to contact us for a consultation.