I have a Furukawa loader and the cutting edge was worn out, I went to equipment dealers and they wanted a lot of money, I wanted a 5/8 x 60 x 7 inch piece I was driving and there was a place that scrapped and rebuilt machinery they gave me the name of a steel outfit that they used, I got it beveled and and welded it in. I live in ROCK CREEK and it is all rock, it is barely smoothed out. I got quoted up to $400 and paid less than $100 for a great piece.
I would look around and maybe someone knows what the good stuff is called but there is no way a cutting edge should wear out that quickly.
If you want to cut rubber mating use a utility knife, and I have an old mustard bottle with solvent in it just a little on the rubber removes the tension and it will cut like butter.
When I worked for a trucking company we use to use a table saw to cut mud flaps.