I bought a similar set. I only wanted to use the 0.5 degree one and I thought there was a taper on it. I've got the 0.25 and 1 degree ones here - just checked them with digital calipers and they're flat, so maybe I was wrong about the 0.5. Oh well, take the 1 degree shim, stick it to something flat with some double sided tape, and sand it down at an angle - DIY shim.