13 products
SKX013 Replacement & Conversion Cases for Seiko Mod
Find SKX013 cases for Seiko mod builds from 13 options at Watch&Style. The SKX013 is the smaller 38mm sibling of the SKX007 — better suited for slimmer wrists and dressier builds — and this collection covers both straight replacement cases that swap the stock SKX013 case directly and conversion cases that adapt SKX013 internals into different Seiko homage styles. Whether you're refurbishing a worn SKX013, rebuilding around an NH35 or NH36 movement, or starting a fresh SKX013 donor conversion project, this is where you find the case that defines your build.
Why Build on the SKX013 Platform
The SKX013 shares the 28.5mm dial diameter standard with its larger SKX007 sibling, meaning the broader Seiko mod dial ecosystem fits both — but the case itself is significantly more compact at 38mm with a 20mm lug width (vs. SKX007's 42mm case and 22mm lugs). For modders with smaller wrists, dressier build aesthetics, or vintage-inspired projects that suit a more restrained case profile, the SKX013 is the platform of choice. The bezels, inserts, crystals, crowns, and bracelets are all sized specifically for the SKX013 case family and are not interchangeable with SKX007 parts.
Style References & Conversion Options
The collection covers four distinct design directions for the SKX013 platform. SKX013 replacement cases (4 options) deliver straight stock-style replacements in silver, matte black, and crown-guard variants — including a 3 o'clock crown variant and a no-crown-guard option for cleaner, more minimal builds. Sub Style conversion cases (4 options) transform the SKX013 into a compact Submariner-style homage in silver, sandblasted black, gold, and rose gold finishes — the most colorful sub-category in the collection. Mini Turtle conversion cases (3 options) adapt the SKX013 into a compact cushion-cased diver homage, available in both 3 o'clock and 3.8 o'clock crown positions and silver or sandblasted finishes. Samurai conversion cases (2 options) deliver the angular tactical-diver aesthetic in steel and sandblasted black at the premium end of the collection.
Crown Position, Sizes & Finishes
Several conversion cases — particularly the Mini Turtle and standard replacement variants — are offered in both 3 o'clock and 3.8 o'clock crown positions to match your preferred wearing orientation and dial layout. Finishes include polished steel (7 options, the dominant choice), matte black (4 options), gold, and rose gold — the broadest finish range applies to the Sub Style conversions, which carry the full color spectrum for builds that step beyond plain steel.
Movement Compatibility & Building Around Your Case
These SKX013 cases are built around the NH35 and NH36 movement footprint — the standard automatic movements for modern Seiko mod builds — and also accept the original 7s26 movement from SKX013 donor watches. Select cases in this collection are also engineered for the NH34 GMT movement, opening the door to compact GMT builds on the SKX013 platform (check individual product descriptions to confirm NH34 compatibility, as not every case in the collection is NH34-rated). Pair your case with matching SKX013-specific bezels, bezel inserts, dials, hands, chapter rings, crystals, and bracelets from adjacent collections to complete your build.
Frequently Asked Questions
What's the difference between SKX013 and SKX007 cases?
The SKX007 is the standard 42mm Seiko diver case (42.5mm to be precise) with 22mm lug width. The SKX013 is its smaller 38mm sibling with 20mm lug width — better for slimmer wrists and dressier builds. Both cases share the same 28.5mm dial diameter, so dials are cross-compatible. However, their bezels, inserts, crystals, crowns, and bracelets use different dimensions and are not interchangeable. Always match those parts to your case size.
Will an NH35, NH36, or NH34 movement fit these SKX013 cases?
Yes. The cases in this collection are built around the NH35 and NH36 movement footprint, the standard for modern Seiko mod builds, and they also accept the original 7s26 movement from SKX013 donor watches. Select cases are also compatible with the NH34 GMT movement for compact GMT builds on the SKX013 platform — check individual product descriptions to confirm NH34 compatibility before sourcing your movement.
What's the difference between a 3 o'clock and 3.8 o'clock crown position?
The 3 o'clock crown position places the crown directly opposite the 9 o'clock marker — the layout found on most classic dress and field watches. The 3.8 o'clock position places it slightly lower, closer to the position found on stock SKX-family divers and many diver homage styles. Important: the crown position of your case must match the crown position your dial is cut for. Pairing a 3 o'clock dial with a 3.8 o'clock case (or vice versa) will misalign the date window with the dial's date cutout — so always match dial crown position to case crown position when sourcing parts.
Browse the full SKX013 case collection above to find the case that defines your next compact Seiko mod build.