Left handed drills are primarily used for removing broken bolts and most bolts are made of high quality. When drilling out the broken bolt, the first cutting edge (pilot hole) worked perfectly, the second cutting edge broke. This was my first time using this new racket. Now I had a broken bolt and a drill in it. After many hours, lots of profanity and a few crooked beats, the mess was fixed. The box does not say which country these bits were made in. I do not recommend this product.