Guide
Seiko mod tool list
A Seiko mod is a series of small jobs: open the case, swap parts, close it again without dust, fingerprints or a scratched dial. The tool list follows those jobs. Buy for the parts you are actually changing on the first build, and add specialty tools when a second build needs them.
Essential for any build
| Tool | What it is for | Why not improvise |
|---|---|---|
| Case holder | Holds the case while you open the back and work on it | A case that turns under the wrench is how backs get scratched |
| Case back wrench or die set | Opens the screw-down case back | Pliers and knives slip and cut the back |
| Movement holder | Supports the movement out of the case | Resting a movement on the stem or rotor bends parts |
| Precision screwdrivers | Movement and case screws | A blade that does not fill the slot rounds the head |
| Tweezers (brass or plastic tipped) | Small parts, gaskets, dial feet | Fingers leave oils on dials and hands |
| Finger cots or nitrile gloves | Keeps skin oil off the dial and crystal | Fingerprints under the crystal are permanent until you reopen it |
| Air blower | Dust off dial and crystal before closing | Breath adds moisture |
| Loupe | Checking hand clearance and dust | Problems are invisible at arm's length |
| Dust-free work surface | A clean mat under everything | Dust gets under the crystal |
Hands and dial
- Hand removal tool (hand levers or a hand puller) and a dial protector, a thin plastic sheet slipped under the hands so the levers do not touch the dial.
- Hand setting tool or hand press, to press new hands on straight and at the right height.
- Rodico or similar cleaning putty for lifting dust without scratching.
Bezel and crystal
- Bezel removal tool or a thin case knife for press-fit bezels, used at the gap with tape on the case.
- Crystal press with dies for press-fit crystals and gaskets.
Straps and bracelets
A good spring bar tool for fitting the head to its strap or bracelet, and a pin pusher and holder for sizing a bracelet. See the Seiko bracelet guide for pin and collar links.
What can wait
Movement servicing tools, timegraphers, pressure testers and demagnetizers are useful later, but not for a first parts swap. If your mod needs water resistance, have the finished watch pressure tested by a watchmaker instead of buying a tester for one build.
Compatibility firstBefore you buy parts, confirm the case, movement and dial are compatible, including dial feet position and hand hole sizes. The right tools cannot fix incompatible parts.
FAQ
What tools do I need for a first Seiko mod?
A case holder, a case back wrench, a movement holder, precision screwdrivers, tweezers, finger cots, an air blower, a loupe, hand levers with a dial protector and a hand setting tool. Add a crystal press and bezel tool if you change those parts.
Do I need a pressure tester for a Seiko mod?
Not for a first build. Have the finished watch pressure tested by a watchmaker if you need water resistance.
Can I use a watch tool kit for a Seiko mod?
A general kit covers straps, bracelets and case backs. Hand and dial work needs dedicated hand levers, a dial protector and a hand press, which most kits do not include.