Skill level 
Sawing stainless steel cable presents a couple of challenges. The first is that the sawed ends tend to fray just like a rope cut with a dull knife but in this case the individual wires can be bent and don’t spring back. These frayed ends do not fit well into tight-fitting terminals. The second problem is that the cable will flex back and forth as you try to saw it, which only makes it more difficult to cut cleanly.
People typically suggest first wrapping electrician’s tape around the cable where you are going to cut it. This will reduce, but not eliminate, fraying. It does absolutely nothing to keep the cable from bending and rolling as you saw it. I couldn’t figure out how to put it in a vice or clamp it down close enough to the cut on both sides to hold it firmly. The simple solution to both problems starts with an ordinary block of wood.
I found a piece of wood about 2” x 2” x 6” and drilled a 7/32” hole all the way through one of the shorter dimensions about 1” from the end and centered. I wanted the hole slightly larger than the 3/16” cable so that it would hold the cable yet allow it to slide through easily. Then I stood the block up in the vise with the hole parallel to a long wall so that I would have plenty of room to stretch out the cable. Using an ordinary wood hand saw I made a cut perpendicular to the hole and deep enough to pass through the hole.
The hole in the jig holds both sides of the cable firmly so that they don’t move and don’t fray, while the kerf guides the hacksaw as it does its work. The jig doubles as an extra pair of hands to tame the cable, which always wants to coil back up.
