10PCS Water Bottle Cage Bolts Holder Screws, Bike Bicycle Cycling Bracket Rack Bolts Screws Accessories, Stainless Steel M5x12mm Hex Socket Head Screw

These are good quality hardware. I had no problem with them threading into my bike mounts and they function perfectly with a 4mm hex key

Works perfectly for a pair of electric bikes that needed bottles mounted.

Used the bolts to repair mountain bike.

These are sized and threaded for bicycle down tubes and seat tubes, for attaching water bottle holders and other assorted accessories that are slim enough to not interfere with pedaling. I personally attach a water bottle holder to the seat tube and my bike lock on the down tube. Of course, they are tightened with a allen wrench, but with the ribbing on the head, you can hand tighten them upon insertion until it's time to use the allen wrench. These are supposed to be stainless steel. In time, if they rust, I'll update this review; however, all indications is that they will stand up to the elements just fine.

I was looking for inexpensive bottle holder screws and these fit the bill they're a little bulky but if you're just a daytime or like me that bobbles around on the bike with the dogs? They were just fine. The three stars is simply because they're clunky and I know that bike people like things to look a lot better than this. But they work fine.

Well machined, accurately sized, good quality parts.