These bits have a carbide end brazed onto the tip. The brazed connection is stronger than the carbide and will hold up longer than the carbide or the HSS shaft. These bits will drill through hardened steel. The flutes are straight to clear the chips better typically generated from hardened steel. The price of these bits is about half of what you would pay for full carbide bits. Solid carbide bits are quite fragile and will snap easily if subjected to any side torque. Since the body of these bits is HSS, they are quite a bit tougher.