Oblong slot punch in three sizes:
An economical slot punch for cutting the oblong hole used in belt making that allows the buckle prong to move freely.
As an approximate guide use the slot length equal to the width of the buckle, i.e. for a 25mm buckle use a 25mm slot punch.
To create longer slots move the slot further along and make an additional cut.
To keep the edges sharp ensure you are cutting into a cutting mat or poundo board.
Tip: To prolong the life and sharpness of your chisels and punches push them into a beeswax block before use.