I'm not sure what the problem is, but if it's any help, it should be one long piece of thread, the thread goes through the hole in the blade, and loops back through, in, say, a clove hitch, and you do it again, stringing the next blade ten inches away.
The thread loops around the end, not the cutting edge, so the razor blade hangs straight up and down. I'm assuming you're using blades like this.
BTW, Bruce Elliott in Classic Secrets Of Magic
suggests "strong white carpet thread" but you might want to experiment with dental floss. Classic Secrets Of Magic
describes Lee Noble's routine, which produced ten razor blades in a string almost ten feet long. Looking at the illustrations, I see they're not to scale, if you have that book, but they show the stringing fairly well.