One-sided double-shoulder spring bar - ISOSWISS

This double-shouldered monolateral spring bar - ISO Swiss is a precision watch part used to connect a strap or bracelet to the case of a wristwatch, or to anchor a folding clasp to the bracelet itself. Sold individually, it is offered in several lengths and diameters so that you can replace a worn or corroded original part with an exact match and restore the watch to full working order.

Product overview

The spring bar is the small spring-loaded rod that sits inside the lug holes of a watch and keeps the strap firmly attached to the case. When the original spring bar weakens, rusts or breaks, the watch can fall off the wrist — replacing it with a high-grade reference such as this double-shouldered monolateral spring bar - ISO Swiss is therefore one of the most important small repairs you can carry out. Single-sided compression, several lengths and diameters.

Technical specifications

• Reference type: double-shouldered monolateral spring bar - ISO Swiss
• Material: 316L stainless steel or equivalent corrosion-resistant alloy
• Dimensions: single-sided compression, several lengths and diameters
• End style: double shoulder mono iso
• Compatible with: integrated-bracelet sport watches, Tudor, Tissot PRX-style
• Typical use: bracelets with one fixed and one sprung lug-side, integrated bracelet cases
• Packaging: sold individually so you order only what you need

When to use it

Choose this double-shouldered monolateral spring bar - ISO Swiss when the original spring bar on your watch is corroded, has lost its spring or no longer holds the strap securely. It is also the part to use when you fit a new strap — a NATO, leather, rubber or silicone band — because the diameter and length of the bar must match the lug width and the lug-hole geometry. Slim dress watches typically need a thinner bar; sport watches and divers from Seiko, Omega Seamaster, Tudor Pelagos or Rolex Submariner generations need a bar sized for heavier loads.

How to fit it — step by step

1. Measure the lug width with a caliper and verify the diameter and length you need.
2. Compare the existing spring bar with the new one: the shoulder and tip style must match.
3. Using a spring bar tool, compress the worn bar and remove it from the lug holes.
4. Slide the new spring bar into the strap or into the end-piece of the bracelet.
5. Insert one tip into the first lug hole, then compress the second tip with the fork of the tool.
6. Release the tip into the opposite lug hole and listen for the audible click.
7. Pull gently on the strap to verify that both tips are fully engaged before wearing the watch.

Quality and origin

Our spring bars are sourced from established Swiss suppliers such as ISO Swiss and from quality stainless steel manufacturing partners. The 316L stainless steel grade is preferred because of its low carbon content, which improves corrosion resistance in chlorinated, salty or humid environments — essential for dive watches and for daily wear. Each reference is checked dimensionally to keep manufacturing tolerances tight, so the new bar drops cleanly into the lug holes of brands like Rolex, Omega, Tudor and Seiko without filing.

Frequently asked questions

How do I know which diameter I need? Measure the original spring bar with a digital caliper, or take note of the diameter written on the side of the bag of the previous reference. Common diameters range from 1.30 mm to 1.80 mm.

Will this spring bar fit my Rolex or Omega bracelet? Many integrated steel bracelets use specific shouldered or grooved bars; check the end style against your existing part before ordering.

What if the new bar is slightly too long? Compress it with the spring bar tool fork — a small over-length is normal and helps the tips seat firmly inside the lug holes.