The law also says that “any knife having a double-edged blade” is banned in mass

What Double Edged Blade Means

The law also says that “any knife having a double-edged blade” is banned. The law here states no length or size. Even if you have a double edged survival knife (where one side is a straight blade and the other side is a serrated blade), it would still be illegal.

The logic behind this is that a double edged knife’s purpose is more towards attack than utility. By having two edges, the second edge serves as a liability during utility use. Also, having two blades allows one to slash in any direction as well as stab.