Kensington Watches
Seiko 5 Sports 40mm Mens Watch Black

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Seiko

Seiko 5 Sports 40mm Mens Watch Black

Ref. SRPE55K1

Among our 166 Seiko watchesThis watch£260
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Stepping up in the same colour and case shape

Price range £110 to £2,900 across 166 Seiko watches in stock.

The 40mm stainless steel case measures 11.5mm thick with a 44.6mm lug-to-lug span, sitting neatly on the wrist without bulk. The polished fixed bezel frames a matte black dial carrying LumiBrite-coated hands and hour indices, with a small seconds subdial and a day-date window at three o'clock. The crown sits recessed at four o'clock. A Hardlex crystal protects the dial, while a see-through screw caseback reveals the 4R36 automatic movement — 24 jewels, 41 hours of power reserve. The three-link bracelet fastens with a three-fold clasp with dual push-button release.

Reference
SRPE55K1
Brand
Seiko
Case size
40mm
Case thickness
11.5mm
Case material
Stainless steel
Case shape
Round
Dial
Black
Crystal
Hardlex
Movement
Automatic
Calibre
4R36
Functions
Day-date
Water resistance
100m
Bracelet / strap
Stainless steel bracelet
Strap colour
Silver
Clasp
Three-fold clasp
Lume
LumiBrite
Retailer
Mappin & Webb
Additional specifications
Lug-to-lug
44.6mm
Power reserve
41 hours
Weight
142g
Learn more about Seiko

Kintaro Hattori opened a watch and clock shop in Tokyo in 1881, aged twenty-one, and began manufacturing under the name Seikosha — roughly, house of exquisite workmanship — in 1892. The Seiko name appeared on watches from 1924.

The company's significance is that it broke the Swiss monopoly twice. First on precision: Seiko was appointed official timekeeper of the 1964 Tokyo Olympics and built the quartz chronometers and printing timers to do it, and in the 1960s its movements placed highly at the Neuchâtel and Geneva observatory trials against the best Swiss houses.

Then on technology. On Christmas Day 1969 Seiko released the Astron, the world's first quartz wristwatch, accurate to five seconds a month where mechanical watches managed that per day. The consequences for Switzerland were catastrophic — employment in the Swiss industry fell by roughly two-thirds over the following decade. Seiko deliberately did not enforce its quartz patents, allowing the technology to spread.

The same year it produced the 6139, among the first automatic chronographs, and it has since introduced Kinetic, Spring Drive — a hybrid regulating a mechanical mainspring electronically, giving a perfectly gliding seconds hand — and its own dive and field lines.

Seiko remains fully vertically integrated, making its own hairsprings, quartz crystals, and even the Zaratsu-polished cases, at price points from under a hundred pounds upward.

1881
Kintaro Hattori opens his Tokyo shop.
1924
The first watches carry the Seiko name.
1964
Official timekeeper of the Tokyo Olympics.
1969
The Astron becomes the first quartz wristwatch.
1999
Spring Drive enters production.

All Seiko watches

Also in 3 collections

This watch appears in Stainless Steel Watches (2,782), Automatic Watches (1,540) and Automatic Watches Under £500 (306).

Best of 2 retailers

What the specifications mean

A mechanical watch for everyday wear.

Strengths

  • 100m water resistance covers swimming and watersports
  • 40mm suits most wrists
  • 44.6mm lug-to-lug keeps the 40mm case wearable
  • Luminous hands and markers for low light
  • Sits in the lower half of Seiko's range as we list it
Best forSwimmingEveryday wear

Seiko 5 Sports alternatives

Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.

5 Sports 40mm Mens Watch Black compared with 2 alternatives from other brands
SpecificationThis watch5 Sports 40mm Mens Watch BlackSRPE55K1RotaryRGB10078/04 Apex100 Skeleton Automatic Bracelet Watch - W13326RGB10078/04TissotPRX Digital 40mm Unisex Watch GreyT1374631103000
Price£260£265£265
Case size40mm40mm40mm
Water resistance100m100m100m
MovementAutomaticAutomaticAutomatic
StrapStainless steel braceletStainless steel braceletStainless steel bracelet
Power reserve41 hours
This watchClosely matchedClosely matched

Your new watch

Frequently asked questions, and things you should know about this watch

Can I swim with it?

Yes. At 100m it is rated for swimming and snorkelling, though not for diving.

Water resistance explained

Will the glass scratch?

It resists most everyday knocks. Hardlex is a hardened mineral glass — tougher than standard mineral, softer than sapphire.

Sapphire, mineral and acrylic compared

Does it need a battery?

No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.

Quartz, automatic and solar compared

How long does it run for when it's not worn?

About 41 hours fully wound — enough to survive a night off the wrist, but not a full weekend.

Will it fit my wrist?

Lug-to-lug is 44.6mm, which suits wrists from roughly 16cm (6¼ inches) upward.

Lug-to-lug decides fit more than case diameter does.

How to size a watch to your wrist

Is it a men's or women's watch?

Listed as men's, though at 40mm it sits in the range that suits anyone.

Cheapest place to buy

Both Mappin & Webb and Goldsmiths list it at £260, so choose on delivery and warranty rather than price.

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