NATO Watch Straps: How to Choose, Fit and Replace One

A NATO strap is a single long band of woven nylon that threads under the watch, through both spring bars, and fastens with a buckle. It’s cheap, tough and comes in every colour imaginable, which is why it has outlived its military origins by half a century. If your current strap is cracked, smelly or just boring, a NATO is one of the easiest upgrades you can make.

Where it comes from

The design goes back to a strap issued by the British Ministry of Defence in the early 1970s. Soldiers had to requisition it with a stores form called the G1098, so collectors still call the original style a “G10”. The name NATO came later, from the NATO Stock Number the strap was given.

The design had a practical purpose. Because the band passes under the watch and through both spring bars, the watch stays on your wrist even if one spring bar breaks. The extra layer of fabric under the case also keeps cold metal off your skin.

Getting the size right

NATO straps are sold by width, which must match the gap between your watch’s lugs (the horns either side of the case).

1. Measure the space between the lugs with a ruler or calipers, in millimetres. The most common sizes are 18, 20 and 22 mm.
2. Check your watch’s spec sheet or the back of the old strap, where the width is often stamped.
3. If you’re between sizes, go with the exact match. A strap that’s too narrow slides side to side; one that’s too wide won’t fit at all.

Length matters too. Standard straps suit average wrists; long versions exist for larger wrists or for wearing over a sleeve. The tail end tucks back through the keepers.

Materials and what they’re good for

• Nylon is the classic: light, quick-drying and nearly indestructible. Ribbed or seatbelt-weave nylon is thicker and softer.
• Leather NATOs look dressier and age nicely but don’t like water.
• Rubber and FKM versions are best for swimming and sweat.
• Elastic and sailcloth variants trade some ruggedness for comfort.

Hardware is worth a look. Brushed or polished stainless steel buckles and keepers hold up for years; thin plated ones can bend or wear through.

One thing to check first: height

Because the strap runs under the case, a NATO lifts the watch a few millimetres off the wrist. On thin dress watches this barely shows. On a thick dive watch it can feel tall. If that bothers you, look for a single-pass or “zulu-style” strap, which runs only once under the case.

How to change it

You’ll need a spring bar tool, or a small flat blade if you’re careful.

1. Push the forked end of the tool against the shoulder of the spring bar on the old strap and ease it out of the lug hole. Do the same on the other side.
2. Put the spring bars back into the lugs without a strap, pressing each end in until it clicks into its hole. Give them a tug to check they’re seated.
3. Thread the long end of the NATO strap down through the top spring bar, under the case, and out through the bottom spring bar.
4. Pass the end through the buckle and fasten it on your wrist, then tuck the spare length through the keepers.

The whole job takes about five minutes. If your watch is expensive, a strap change at a watch shop costs little and saves scratched lugs.

Care

Most nylon NATOs can be hand-washed with mild soap and left to air dry. Rinse them after swimming in salt or chlorinated water. Leather straps just need wiping and the occasional conditioner, and should be kept dry.

The bottom line

Measure your lug width, pick a material that fits how you use the watch, and choose solid steel hardware. A good NATO strap costs little, takes minutes to fit, and can make an old watch feel new.