Improve the fit to be more consistent. I made another 10 inch test piece and as I flipped it the router started vibrating and came loose. After removing the plug, I examined the router and found that the blade had bent almost 90°, splitting the router's plastic stand that holds the router to the router table. This happened with the free rotation of the blade, there was no tension from cutting. The blade is of very poor quality to bend like that. Luckily I wasn't hurt and the router table wasn't damaged. The stand under the table withstood a few hits. I would not recommend these blades and I will be returning them asap for a refund.