The information below speaks to common heat treated alloy steel drives (black steel) made to ANSI or DIN specifications. Exotic and non-sparking alloys will have different values which are typically lower than for heat treated black steel. Generally speaking, the limiting factor on torque for most larger impact sockets is the size of the square drive, due to the fact that on such sockets the square drive size is smaller than the nut opening size. Just as a chain is only as strong as its weakest link, an impact socket/power tool connection is generally limited by the smaller mass of the two connections.For example, a typical 3-1/2″ AF hex impact socket may well be capable of handling many thousands of Ft-Lbs of torque, but if the square drive on that socket is only 3/4″ drive, the torque it can be used for is extremely limited by drive size, but not the drive of the impact socket itself. It will be effectively reduced in the load it can be used for, not at all by wall thicknesses or the type of alloy or hardness – or any property of the socket at all for that matter – but instead reduced by the inherent limitations of the 3/4″ section of steel driving it, on the end of the impact wrench itself. In this example, the impact wrench square drive is thus limiting the load, not the impact socket.Conversely, if the square drive is large, and nut end is small (such as a 1-1/2″ drive socket with a little 7/8″ 12-point nut size), you will be limited to what is appropriate for a 7/8″ nut, even though your 1-1/2″ drive tool might be capable of delivering 10,000 ft-lbs. The smallest connection (nut size versus square drive) is generally the limiting factor when evaluating socket sizes and square drives to determine reasonable torque limits.Industry standard impact sockets (those meeting ANSI, ASME, specifications for example) are generally designed to handle the amount of torque typical to the NUT SIZE it fits with, regardless of square drive size. So generally speaking a size 7/8″ socket will be deemed appropriate for loads common to a 7/8″ nut, whether the drive size is 3/8″ or 1-1/2″ drive. All of Deltec Industries steel designs exceed ANSI/ASME B107 load test requirements, and all of our products are designed for heavy duty industrial applications where loads are taken to the maximum limits. In applications where rust, fouled threads, or other problems are causing extremely high loads on Modern materials innovations in steel alloys have extended the amount of force common square drives can withstand well above the limitations of the past, however, specific limitations still exist between drive sizes, and the following guidelines should be kept in mind when deciding on which drive size to choose for your application.The strength of the socket will generally be designed to deliver torque appropriate to the nut size it fits onto, regardless of how large the square drive is. If you require an Extreme Duty design please feel free to discuss your application with us, to determine if an Extreme Duty impact socket is the best choice, or if our normal industrial grade designs will do the job.