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Seiko Mod Cases for Every Build
Every case here is an aftermarket case for a Seiko mod build, and each names the watch or size it's made for and the parts it takes. Most are 316L stainless steel, with titanium and bronze cases among them. Choose by the watch you're building on.
Cases by Watch
- SKX007 & SRPD: replacement cases in the SKX007 shape, and conversion cases in other shapes, from the Samurai and Tuna to the 62mas, 6105 and Marine Master, that still take SKX007 parts. Most state their lug width, and many name the bracelet they take.
- SKX013: Sub, replacement, Mini Turtle and Samurai cases, made to take original SKX013 parts, each with a sterile case back for the NH movement.
- SRPE: 38mm cases with a screw-down crown at 3 or 3.8 o'clock. They take SRPE parts except the crown; use an SKX013 crown.
- SRP Turtle: a replacement case made to take the Turtle Re-issue's original parts.
- 36mm, 38mm, 40mm and Alpinist style: Explorer and fluted bezels and Alpinist-style cases, each with 20mm lugs and a sapphire crystal, and almost all made for a 28.5mm dial.
Before You Order
Lug width, crown position and the movement a case takes change from one case to the next. Check the case's own page against your bracelet, crown and movement before you order.
Frequently Asked Questions
Which case do I need?
Choose by the watch you're building on: SKX007 and SRPD, SKX013, SRPE, SRP Turtle, or a 36mm to 40mm build. Each case names the parts it takes.
Which movements do the cases take?
It depends on the case, and most list it. The SKX013 cases take the NH35, NH38 or NH34; the 36mm and 40mm cases the NH35 or NH36; the Alpinist-style cases with a steel bezel the 7S, 4R, NH35, NH36 or NH38; the fluted ones the NH or 4R, as each page says; and the GMT Alpinist-style cases the NH34.
Are there titanium cases?
Yes: titanium SKX007-shape and Samurai cases, and 36mm Explorer-style cases in grade 2 titanium.
Which crown fits an SRPE replacement case?
An SKX013 crown. Neither an original nor a replacement SRPE crown fits the SRPE replacement cases.
Browse every case above to find the one for your build.