Reassembly Tips ...

How to assemble your TWSBI piston filler ...


  1. Wind plunger head fully down to writing end*
  2. Place spanner between end cap and barrel
  3. Turn spanner clockwise to loosen
  4. Pull plunger mechanism out of pen barrel

*If plunger is jammed, remove nib and use syringe to inject grease into pen body, then try again
*If plunger head is off the rod, poke unfolded paper clip through grip section to push all parts out


  1. Insert black screw-bolt into connector 
  2. Screw end cap in clockwise direction - almost fully on - until thread is no longer visible
  3. Insert plunger into other end (square hole) of connector and wind plunger down
  4. Check for space between the plunger head and connector - you want a 2-3mm space
    If larger, wind end cap anti-clockwise, push on plunger head to 'jump' rod down a notch, repeat
    If too small, start assembly again and for Step 2 wind the end cap on a bit further
  5. Add silicon grease to plunger head
  6. Wind out plunger and insert plunger into barrel
  7. Unscrew end cap slightly (anti-clockwise) to fit spanner in
  8. Turn spanner anti-clockwise to tighten mechanism in the barrel
  9. Check for the 2-3mm between plunger and connector
    Large space reduces ink capacity, small space stops end cap from staying on properly
  10. Replace nib (and for Eco and Go models, check nib is fully seated by pushing it in firmly)

Filling tips

  1. Wind end cap anti-clockwise to put plunger head near nib
  2. Place nib fully under ink
  3. Wind end cap clockwise (slowly) to draw ink into pen
  4. Use tissue to soak excess ink from feed (to balance ink/air pressure inside barrel)