The fuller (sometimes erroneously referred to as a 'blood groove') is a method of reducing the weight of a blade without signicantly reducing its strength when cutting. This is similar in principle to I beams in buildings.

Fullers are not given to sword blades that are designed primarily for thrusting as they are weak when flexed sideways, as might occur during a thrust.

MisconceptionsEdit

• the groove allows a sword blade to be withdrawn
• the fuller somehow strengthens the blade.