I like the metal chip guard. I got a bunch of pieces of stainless sheet cut up at the laser shop (had a job going that needed laser work). So I have a selection of sizes, and a bunch of pieces I don't mind cutting down (still have not cut the original Kurt strips).
Is it "spring steel"? I thought it was just mild steel strip (about 0.015" thick). I purchased 3 DX6 vises in the past year, the first two came with the well hidden steel strip. I got my 3rd one about a month ago - no steel strip (tore the box completely apart). I contacted the supplier, who contacted Kurt - the reply was that the strip is no longer supplied (now if you want it you have to order it separately).
The stainless sheet material I had laser cut was ~0.034". It is probably a bit too thick, it works fine in the first two vises, but is too thick for #3 (oh well) - obviously you don't want to prop up the jaw or the work/parallel/spacer. The laser cuts are pretty, but simply cut up some sheet metal (carbon steel, stainless, aluminum), it would work just fine. Keep a selection on hand so it extends a little ways under each jaw (guessing there is about 3/4" of room for the strip to go under each jaw).
It will probably work fine with out the steel strip - regardless chips get on the screw (is there a benefit of not quite as many chips loading up inside the vise?).
The O-rings? I am not familiar with them, can't comment.
Problem is "I just need one more" (have the old Kurt with the jaw over on the back end).
