Seiko 5 Sports lug width

Watch line39 references

Lug widths across the line

22 mm is the most common lug width on the Seiko 5 Sports: 16 of the 28 references with a known width (57%). Other references use 20 mm, 18 mm, so check your exact reference.

Filter references by lug width

Indicative information. Check your watch before buying a strap: whatsmylugwidth.com is not responsible for an incorrect size. Report an error

39 Seiko 5 Sports references

The story of the Seiko 5 Sports

In November 1973 astronaut William Pogue took a yellow-dial Seiko he had bought for $71 at an air base kiosk into orbit. NASA had not approved it, yet it timed rocket burns on his left wrist for 84 days aboard Skylab.

1,214orbits of Earth made by Pogue's Seiko on Skylab 4
10,500 yenentry price of a 5 Sports in 1968, about US$29
15,555pieces of the 2023 55th-anniversary re-creation

Chapters

  1. 2020 to today
    Guitars, dragons, anniversaries

    Collaborations followed: a 9,000-piece Brian May edition in 2020 and, for the 55th anniversary in 2023, a 15,555-piece re-creation of the original plus a Bruce Lee edition. In 2025 the SKX399 returned in four colours, and Time+Tide counts 75 models in the range.

  2. 2019
    Relaunch

    Seiko relaunched 5 Sports in 2019 with a more youthful dynamism; the line runs on the 4R36 automatic with a 41-hour reserve.

  3. 1998 to 2018
    The SKX years

    The SKX399, launched in 1998, became a successful sports classic at an accessible price and one of Seiko's most beloved designs, reissued in 2025.

  4. 1969 to 1970s
    The automatic chronograph

    In spring 1969 Seiko launched the calibre 6139 "5 Sports Speed-Timer", which it calls the world's first automatic chronograph. Bruce Lee favoured a 6139, and William Pogue carried one to Skylab.

  5. 1968
    A sports watch for everyone

    The first 5 Sports models had faceted cases, rotating bezels, Hardlex crystals and 70 m water resistance, aimed at a younger, active buyer. At 10,500 to 15,000 yen they cost roughly a fifth of a Rolex Submariner or less.

Worn by

William PogueSpace1973

He wore his own 6139 Speed-Timer on his left wrist, next to his NASA-issued Omega, during the 84-day Skylab 4 mission, and kept wearing it for 19 years after.

Bruce LeeScreen

Time+Tide calls him the most famous real-life 5 Sports wearer; he long favoured the 6139-6010. Seiko honoured him with a 2023 edition.

Young MazinoScreen

He wore a 5 Sports SRPG39 on HBO's The Last of Us, though the model postdates the show's setting.

Noah WyleScreen

His doctor character on The Pitt wears a 5 Sports, and some watch aficionados objected to the fabric strap in an emergency room.

Moments

2023. The 15,000-piece Bruce Lee edition put his own dragon drawing on the dial and Jeet Kune Do characters on the bezel.

2020. The Brian May edition carried his signature on the back and came in a box modelled on his guitar's flight case, with a coin recalling the sixpence he uses as a plectrum.

1969. Seiko's 6139 beat the Swiss Calibre 11 consortium of Heuer, Breitling and Hamilton-Buren to market in the race for the automatic chronograph.

Generations and strap changes

  1. 2023
    55th anniversary

    SRPK17 recreated the 1968 model in 39.5 mm, limited to 15,555 units, alongside new 42.5 mm SKX Sports Style models.

  2. 2022
    SKX Style GMT

    The SSK001K1, SSK003K1 and SSK005K1 added a GMT hand via the 4R34, in a 42.5 mm case 0.1 mm taller than before.

    Five-row steel bracelet with polished centre links and triple-fold clasp.

  3. 2019
    Collection relaunch

    Seiko relaunched 5 Sports with 27 models in five styles, a 42.5 mm case and the 4R36 calibre.

    Launched on steel bracelets and straps ranging from steel mesh to silicone/leather hybrids.

  4. 1968
    Seiko 5 Sports born

    Seiko introduced Seiko 5 Sports for people who wanted a watch for sports.

  5. 1963
    Sportsmatic 5

    The first Seiko 5, the Sportsmatic 5, was Japan's first automatic day-date watch.

Firsts and innovations

Seiko states that the 1963 Sportsmatic 5, the line's ancestor, was Japan's first automatic day-date watch.

FAQ

What lug width does the Seiko 5 Sports use?

Most references use 22 mm (57% of the 28 references with a known width). Some use 20 mm or 18 mm.

Do all Seiko 5 Sports references take the same strap?

No. 3 different lug widths appear across the line, often by case size or generation. Check the reference engraved on the case back or between the lugs.

Help

What is lug width?

The gap between the two lugs that hold the strap, in millimetres. A new strap must match it exactly: 20 mm lugs take a 20 mm strap.

Measure it in 30 seconds

  1. Take the strap off, or look at the back of it: many straps print their width.
  2. Measure the inside gap between the lugs with a caliper or a millimetre ruler.
  3. Round to the nearest whole millimetre. Most watches use 18, 20 or 22 mm.

Strap, quick release or system?

Most watches use spring bars, so any strap of the right width fits. Many smartwatches use their own band system instead, such as Apple Watch bands or Garmin QuickFit.