Those numbers on the helix mean the angle of the helix ramps. If for example it says 51/43, that would mean the angle starts at 51deg and ends at 43deg. Most helixs have angles progressivly cut, meaning the angle changes at a constant rate.
ok , i understand the angles are progressive . what i dont know is what the angles do ? the larger the angle at start means a more aggressive start the progressively slows ?