How to Adjust Different Seiko Mod Straps (Step-by-Step Guide)

Getting the right fit for your watch is essential for comfort and style. Different Seiko mod straps use different adjustment methods — some use tiny screws, some use push pins, and some rubber straps need to be cut.

Here’s a simple guide for six common strap types: Oyster, Jubilee, SeikOak, SeikoNaut, Seikotona, and Aquanut.

1. Oyster Bracelet (Screw Pins)

• Uses screw pins.

• Place the bracelet on the holder block.

• Use the flat screwdriver tool to turn the screw pin counter-clockwise until it comes out.

• Remove or add links.

• Put the pin back in and tighten clockwise.

2. Jubilee Bracelet (Screw Pins)

• Uses screw pins.

• Place the bracelet on the holder block.

• Use the flat screwdriver tool to turn the screw pin counter-clockwise until it comes out.

• Remove or add links.

• Put the pin back in and tighten clockwise.

3. SeikOak Bracelet (Screw Pins)

• Also uses screw pins.

• Place on the holder block.

• Turn the screw out with the flat screwdriver tool.

• Adjust links as needed.

• Insert the screw pin and tighten back in place.

4. SeikoNaut Bracelet (Push Pins)

• This one uses push pins instead of screws.

• Look for small arrows on the inside of the bracelet.

• Place on the holder block with arrows facing down.

• Use the pin tool and hammer to knock the pin out in the direction of the arrow.

• Remove or add links.

• Insert the pin back from the opposite side and tap in until secure.

5. Seikotona Rubber Strap

• First, try the micro-adjustment holes on the clasp.

• Push the small pin out by hand or with the tool.

• Move the clasp to another hole for a better fit.

• If not enough, you’ll need to cut the strap shorter.

• Always cut both sides evenly to keep balance.

6. Aquanut Rubber Strap

• The strap can only be shortened by cutting. Please measure carefully before trimming.
• To remove the clasp: use a spring bar tool (or a thin pin/paperclip) to press the small spring bar that holds the clasp. Take it out gently and keep it safe.
• Mark the strap evenly on both sides. Cut a little at a time with sharp scissors or a cutter, always keeping both sides equal.
• Smooth the cut edge with fine sandpaper or a nail file.
• Reinsert the strap into the clasp and push the spring bar back into place. Make sure it clicks securely.
• Tip: Cut slowly and test after each cut. Once shortened, it cannot be made longer again.

Final Tips

• Adjust slowly and carefully — one step at a time.

• Test the fit before cutting or removing more links.

• After adjusting, pull firmly on the strap/bracelet to ensure everything is secure.

• Always place a thin transparent film (like plastic wrap) between the tool and the watch to prevent scratches during adjustment.