Hi. The Manix is running over 200 inch/lbs per inch of blade which would rate it Very Heavy Duty (same as MBC, but as suggested by a forumite, MBC may not be a good name for the rating considering the large number of customers that have no interest in Martial Blade Craft (MBC).
Hi Cutengineer. Welcome to the Spyderco forum.
There is no governing body that sets rating. Spyderco employs our own in-house rating system in the construction of our designs. We set the desired standard when we design the model and build to that standard. We test (break) the models in development and continue to test (break) the models to ensure that our standards have not changed.
In-house Lock strength standards
Light Duty = over 25 inch/lbs of lock strength per inch of blade length.
Medium Duty = over 50 inch/lbs per inch of blade length.
Heavy Duty = over 100 inch/lbs per inch of blade length.
Very Heavy Duty (MBC) = over 200 inch/lbs of lock strength per inch of blade length.
We also have our standards for G-10 (ours is custom made), blade strength, and other general safety issues.
sal