From Our Friends
powered by ZergNet
I purchased a Zyliss french fry cutter, and it is not able to cut sweet potatoes in any effective way.
You could use a mandoline with a julienne cutter of your desired size if you've got it. Otherwise a chef's knife will do the trick. Just try to make all of them an even thickness so they cook at an even rate.
Sweet potatoes are so hard that you'll have a hard time finding a consumer cutter that will slice them into fried. I'd recommend cutting them by hand or trying a heavier commercial cutter.
I'm thinking of something all metal, similar to these:
http://amzn.to/zZN0W2
http://amzn.to/z36P8m