Assuming that your mast groove is round (i.e. for rope), you may need to look for this in separate pieces - (1)slugs for the track, (2)screws and (3)the right size cleat. Harken makes the necessary parts to attach mast track to a grooved mast via a slug system. There are also other slugs that I've seen in catalogs - one with a knurled knob that keeps the boom/gooseneck at a set height.
You may also be able to simply use a hex nut on the end of the screw and cut the screw to fit (if necessary). Loosely put the nuts on the screws after running through the cleat then run the nuts in the groove and tighten when you get it positioned. However, this would possibly damage the mast groove.
Edit - note that this is only for a horn cleat
Last edited by 14432; 05-21-2009 at 12:19 PM.