The notion that most fighting knives specifically have a 7-inch blade is not entirely accurate. There is no universal standard for the blade length of fighting knives, and the blade length can vary significantly depending on the specific purpose and design of the knife, as well as the preferences of the user or the requirements of the organization or military for which it is intended.
That being said, certain blade lengths are popular in the realm of fighting and combat knives due to various practical considerations. Here are some reasons why a 7-inch blade length might be considered suitable for certain fighting knife designs:
Versatility: A 7-inch blade strikes a balance between being long enough to handle various cutting and slicing tasks and being short enough for close-quarters combat and handling in tight spaces.
Penetration: A longer blade can potentially offer better penetration capabilities, making it effective against armored opponents or tough materials. However, it's worth noting that blade design, edge geometry, and material also play a significant role in penetration effectiveness.
Weight and Maneuverability: A 7-inch blade can be reasonably lightweight, providing the user with a maneuverable and agile knife that can be wielded effectively in hand-to-hand combat scenarios.
Legal Considerations: In some jurisdictions, there may be restrictions on the maximum allowable blade length for carrying knives in public. A 7-inch blade length could be considered a reasonable compromise to comply with such regulations while still maintaining a functional fighting knife.
Tradition and Design Preferences: Over time, certain blade lengths and designs have become popular and established in the world of combat knives due to tradition, historical use, or personal preferences of experienced knife users and experts.
It's important to remember that the suitability of a fighting knife depends on various factors, including the intended use, the training and experience of the user, and the specific requirements of the situation. There is no one-size-fits-all answer when it comes to fighting knife design, and different blade lengths and shapes may be more appropriate for specific combat scenarios.