Fin Bolt for US-Box – M4 Bolt and Slider
This standard us-box fin bolt and slider nut is for use in all US-Box (longboard) fin systems, as typically found on windsurf, surf, SUP and some kite boards.
Genuine part, with the bolt machined from stainless steel, and the bolt machined from brass.
Philips head M4 stainless steel bolt, with an M4 slider nut.
NOTE: This is a high quality M4 bolt, with stronger head. Not a cheaper alternative.
This is an M4 bolt and slider suitable for all US-box type fin boxes...
If your board uses a US-box fin bolt system, this is the genuine bolt and nut to be used in it. The bolt is machined from stainless steel, while the slider nut is machined from brass.
The bolt is available from bigsurfshop.com as a philips head or a flat head screwdriver.
Size of the bolt is M4.
Price illustrated is for 1 no. bolt and 1 no. slider.
Installation of the US-Box M4 fin bolt and slider
Slide the nut into the track of your us-box, put the screw through your fin and then screw bolt into the nut. Tighten until hand tight...don't over tighten!
It's worth while checking that it remains tight during and after use.
Also worth checking if you never remove the fin, that it is not seized into place...this is the same for any component used in open sea water.
