Cutting Guitar Fret Slots HELP!

Fret Tang Size fret slot width TL07 Fret Slot Saw £ Stiff backed with wooden handle, dressed for fret tang width fret slot saw Japanese Fret Slot Saw; Hosco Brand

fret slot width The 1 question I've been wondering about is how wide do you make the fret slot? Some frets say 020 width at the tang is this how wide you