These drill bits are great for brick, mortar and cement and have a nicely shaped oversized tip for relatively easy drilling. I can't judge strength and durability yet, but they don't shy away from serious testing, like new bits. Drill bits should work as long as you drill slowly, use water frequently to avoid overheating, and use pilot holes first if you need a large hole in masonry. too many bits and not enough slots, forcing them to share if you stick with the original case. My solution is to use a stepped holder instead.