Review on Bi Metal YIDEMIL General Purpose Mandrels by Antoine Dean

I usually use a variety of hole saws for a variety of projects, but I almost always have to borrow a very small or very large size as my current sets don't include them. Most kits seem to come with what they consider standard for most people...I'm not most people. I could buy a size I don't have but they can't be more expensive than what I use. My last 2-1/8” was 1/3 the price of this complete set! This kit largely solves that problem and in a very nice case to keep everything organized. They include extra mandrels for each size, which many don't have. The really big difference with this set is how they mount the larger diameter bits. They use a set of locking pins (pictured) that actually go into holes in the top of larger cutters. (They also have a standard arbor for small-diameter cutters.) Those who have used a large-diameter cutter with a standard "tighten as much as possible" arbor similar to the standard version of this kit know they start to slip. This completely eliminates this problem. The incisors are very sharp and quickly make large holes. I can't say how long they will stay this sharp, only time will tell. Bottom line: If you use a variety of hole saws like I do, this set is for you.