S2 steel bit is press-fit into the socket for a straight, permanent connection that can't loosen over time Machined tip has parallel, flat faces for engaging with the straight sides of a fastener slot Large, clear die-stamped size marking is easy to read and can’t wear off Four detent grooves provide a secure connection with the drive tool and a drilled through-hole allows locking on with retaining pin Polished, chrome-plated finish easily wipes clean and is highly resistant to corrosion Beveled inner rim of the socket opening helps guide it smoothly onto fasteners