Grand Seiko Spring Drive

Most Grand Seiko Spring Drive references take a 19 mm watch strap: 17 of 49. The lug width follows the case size: 39 mm case → 19 mm, 40 mm case → 19 mm, 41 mm case → 20 mm and 44 mm case → 21 mm.

Shop 19 mm Shop 20 mm Shop 21 mm Shop 22 mm

Grand Seiko Spring Drive lug width by case size

49 references measured. Updated 2026-10-29.

Case	Lug width	References	Watch strap attachment	For example
39 mm	19 mm · 20 mm on 2	11	—	SBGA225, SBGA227, SBGA273
40 mm	19 mm · 20 mm on 3 · 22 mm on 1	8	—	SBGA293, SBGA362, SBGA385
41 mm	20 mm · 19 mm on 4	12	—	SBGA101, SBGA201, SBGA203
43 mm	22 mm · 20 mm on 2	5	—	SBGD201, SBGD202, SBGD205
44 mm	21 mm · 22 mm on 2 · 20 mm on 1 · 23 mm on 1	10	—	SBGC201, SBGC203, SBGC205
46 mm	23 mm	3	—	SBGC219, SBGC221, SBGC223

References that take a different watch strap

SBGA279: 20 mm, not the 19 mm of most 39 mm cases
SBGA290: 20 mm, not the 19 mm of most 39 mm cases
SBGA361: 20 mm, not the 19 mm of most 40 mm cases
SBGA364: 20 mm, not the 19 mm of most 40 mm cases
SBGE225: 20 mm, not the 19 mm of most 40 mm cases
SLGA007: 22 mm, not the 19 mm of most 40 mm cases
SBGA299: 19 mm, not the 20 mm of most 41 mm cases
SBGA301: 19 mm, not the 20 mm of most 41 mm cases
SBGA347: 19 mm, not the 20 mm of most 41 mm cases
SBGA349: 19 mm, not the 20 mm of most 41 mm cases
SBGD001: 20 mm, not the 22 mm of most 43 mm cases
SBGD207: 20 mm, not the 22 mm of most 43 mm cases
SBGA229: 22 mm, not the 21 mm of most 44 mm cases
SBGA231: 22 mm, not the 21 mm of most 44 mm cases
SBGC204: 23 mm, not the 21 mm of most 44 mm cases
SBGE001: 20 mm, not the 21 mm of most 44 mm cases

Questions about the Grand Seiko Spring Drive

Do all Grand Seiko Spring Drive case sizes take the same watch strap?

No. The lug width changes with the case size: the 39 mm case takes 19 mm, the 40 mm case takes 19 mm, the 41 mm case takes 20 mm, the 43 mm case takes 22 mm and the 44 mm case takes 21 mm. Check your case diameter before you buy.

Can two Grand Seiko Spring Drive watches with a 41 mm case take different watch straps?

Yes. Of the 12 Grand Seiko Spring Drive references with a 41 mm case, 8 take 20 mm and 4 take 19 mm. The reference number decides, not the case size alone.