Linear dimensions are very simply a dimension from one point to another.
Ordinate dimensions are dimensions that are all called out as a single number (often on a leader line w/o a dim. line) that reference a zero start point.
Does this help?
How will the shear be operated? ie, foot pedal, hand lever, automated, etc...? is it operated by highly skilled machinists, or general laborers? Is poduction rate of this operation important?
All these things will point you toward a solution.
The "pure" solution is to prevent...