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How to Get the Correct Size Spring Bars for Your Watch: A Simple Guide

by Luxury Watch Straps

See our collection of superb spring bars / watch pins here.

Spring bars: the unsung heroes of the watch world. These tiny metal rods are what keep your strap attached to your watch case, yet they rarely get the attention they deserve—until one goes flying across the room, never to be seen again. Whether you're swapping out a strap or replacing a worn-out bar, getting the correct size is absolutely essential. Too long and they won’t fit; too short and your watch could end up on the floor (or worse, down a drain).

Here’s a simple, no-fuss guide to help you get the right size spring bars for your watch.

1. Understand What a Spring Bar Is

A spring bar is a small, spring-loaded metal rod with flanges at both ends. It fits inside the lugs of your watch and passes through the holes at the end of the strap. When you compress the bar, the ends retract, allowing you to slot it in or out of the lug holes.

They may be small, but they’re mighty—and choosing the right size is key to keeping your watch secure and comfortable.

2. Measure the Lug Width

The most important measurement you need is the lug width—the distance between the two “arms” (or lugs) of your watch case. This is where the strap fits in, and it’s also where your spring bar sits.

Here’s how to measure it:

  • Use a digital caliper (or a good old-fashioned ruler, if necessary).

  • Measure in millimetres from the inside edge of one lug to the inside edge of the other.

Common lug widths include 18mm, 20mm, 22mm and 24mm, but they can vary—especially with vintage or fashion watches.

3. Match the Spring Bar Length

Once you know your lug width, get spring bars that match exactly. For example, a 20mm lug width needs 20mm spring bars. Don’t guess or assume—1mm too short, and the bar won’t stay in place; 1mm too long, and it won’t compress properly.

Choose the nominal size specified for your lug width, not the uncompressed tip-to-tip measurement of a loose bar. The projecting tips compress during installation. Always check the product specification or ask us if unsure.

4. Choose the Right Type

Spring bars come in various styles, including:

  • Standard: Conventional spring bars; match the length, body diameter and tips to your watch and strap.

  • Fat bars: Thicker-bodied bars. Only use them where the watch and strap or bracelet accommodate their body and tip dimensions. Thicker does not automatically mean a better fit.

  • Quick-release: Have tiny levers for tool-free strap changes. Check that the strap accommodates the lever as well as matching the bar dimensions.

  • Double-flange: Easier to remove using a spring bar tool.

The body diameter is the thickness of the main tube passing through the strap or bracelet. The pivot/tip diameter is the thickness of the projecting ends engaging the lug holes. These are different measurements: a 1.8mm body specification does not establish the tip diameter.

Spring-bar comparison: lug width, body diameter and tips

These are the options specified in our product listings. Lengths are nominal sizes for the measured lug gap. Model examples are starting points to check against your exact watch reference, not universal fit guarantees.

Listed spring-bar options. All dimensions in millimetres.
Product / model example Lug width / nominal size Body diameter Pivot / tip diameter Type / fitting check
Spring bars for Rolex watches 13, 17, 20, 21, 22. Listing example: a Submariner with a measured 20mm gap uses nominal 20mm bars; this does not apply to every reference. 1.8, stated in the product title. Not specified; confirm before ordering. Conventional flanged bars described. Check the original bar and strap or bracelet requirements.
Spring bars for Omega watches 17, 18, 19, 20, 21, 22, 23, 24. No model-specific size mapping supplied. 1.5 or 1.8. Not specified; confirm before ordering. Conventional collared/flanged bars described; no quick-release option specified.
Spring bars for TAG Heuer watches 17, 18, 19, 20, 21, 22, 23, 24. No model-specific size mapping supplied. 1.5 or 1.8. Not specified; confirm before ordering. Replacement spring bars; a quick-release lever is not specified. Confirm end design.
Spring bars for Tudor watches 20, 21, 22. Listing examples: Black Bay Fifty-Eight, Ranger and Black Bay Pro: 20; Pelagos 39: 21; Black Bay GMT and Pelagos 42: 22. Verify your exact reference. 1.5, 1.8 or 2.0.  Not specified; confirm before ordering. Multiple thicknesses, including 2.0. Do not infer a fat-bar or quick-release specification from thickness alone.

Before ordering: check the lug gap, body thickness, tip diameter and end design against the correct original bar or the specification for your exact watch reference and strap or bracelet. 

5. Buy a Few Spares (Trust Us)

Spring bars have a way of vanishing into thin air the moment you drop them. Always have a few extras in the correct size—your future self will thank you.

Final Tip

Don’t force it. If a bar doesn’t slide in smoothly, stop and re-check your measurements. A poorly fitting spring bar could damage your watch—or worse, lead to a costly drop.

With the right size and a steady hand, you’ll have your strap swapped and your watch back on your wrist in no time.

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