show i make the kerf on my box file smaller or larger for a tighter fit and vice versa?
If you want a tighter fit, you make the tabs slightly larger. (We use an offset of half the kerf if we are designing our own.)
If you’re setting a kerf value for a box maker to use in compensating for kerf, then the wider you tell it your kerf is, the tighter the fit will be, because it will make the pieces larger to compensate for the amount of material lost to the kerf.
Thanks for the great advice, everyone! I’m leaving this open for more tips.
Also of note: it’s usually a very short jump from “too loose” to “never getting this together ever”.
A difference in your kerf adjustment of as little as 2-3 thousandths of an inch can completely torpedo your project. For most 0.125 thick materials the kerf adjustment for a really good tight flip mate is somewhere between 0.005” and 0.007”.