How To Change A Watch Strap

Step 1: find your lug width

The lug width is the gap between the lugs, measured in millimeters, and it's the only number you need to buy a strap. Measure across the inside of the gap with a ruler or calipers — it will be an even number, almost always between 18mm and 22mm. Most 38–42mm watches take 20mm; the Seiko 5 Sports SRPD takes 22mm; the Orient Bambino V7 and the Seiko SRPG31 both take 20mm. If a maker publishes it, we list it — never guess and order, because a 1mm error means the strap either won't fit or will rattle.

Step 2: get the right tool

You need a spring bar tool— a small double-ended tool with a forked tip and a pointed tip. They're inexpensive and every strap change is easier and safer with one. Do not use a kitchen knife, a screwdriver or a paperclip: those are how lugs get gouged, and a scratch on the outside of a lug never comes off.

Step 3: remove the old strap

1. Lay the watch face-down on a soft cloth — a folded tea towel is fine. This is the single most important precaution: it protects the crystal and stops the watch sliding.
2. Slide the forked end of the tool between the strap and the lug until it catches the groove in the spring bar.
3. Push the spring bar in towards the center of the watch while gently levering that side of the strap away from the lug. The bar will compress and one end will pop free.
4. Angle the strap out and the other end releases. Repeat for the second strap half.

If a bar won't budge, stop and reposition rather than forcing it. Slipping tools are how cases get scratched, and a spring bar that resists is usually a tool that isn't properly seated in the groove.

Step 4: fit the new strap

1. Thread the spring bar through the new strap's loop.
2. Seat one end of the bar in its hole in the lug.
3. Compress the other end with the forked tip and guide it into the opposite hole. You should feel and hear a small click as it seats.
4. Test it.Tug the strap firmly away from the case. If a bar isn't fully seated, better to find out at your desk than when the watch hits the pavement.

Quick-release bars: the easy mode

Many modern straps ship with quick-release spring bars— a tiny lever on the underside that retracts the pin with a fingernail, no tool required. If you plan to change straps often, buy quick-release straps and the job takes fifteen seconds with nothing sharp near the case. Some watches include them from the factory; the Tissot PRX's integrated bracelet uses a quick-release system, though on that watch you're limited to Tissot's own options because the bracelet is part of the case design.

What strap to buy

• Nylon (NATO or single-pass).Cheapest, toughest, most casual. A NATO passes under the caseback so the watch can't fall off if one bar fails — worth it on a beater. It does add a millimeter or two of height.
• Leather. Dresses a watch up instantly. Keep it away from water; a soaked leather strap will smell and stiffen.
• Rubber or silicone. The right answer for a dive watch you actually swim with.
• Steel bracelet. The most expensive option and the one that needs sizing — links come out with a pin pusher or screwdriver depending on the design.

The one thing to check first

Some watches can't take a standard strap at all. Integrated-bracelet designs like the Citizen Tsuyosa and the Tissot PRXhave a bracelet that is shaped to the case, so there's no flat 20mm gap to fit anything else into. If strap-swapping is part of the fun for you, buy a conventional lugged watch — that flexibility is one of the quiet advantages of a Seiko or Orient over the integrated-bracelet crowd.