There is a break-even point when considering whether to integrate a Thread Verification Station into a production line or just hand feed the Station, where the cost of paying a person to move parts is justified over laying out the capital for an automated device to perform this task, or vice versa. This is typically driven by cycle time and the architecture of the production process. So if you have a relatively slow cycle time, and have the personnel, hand sorting may be the best option.
Until relatively recently, manufacturers of auto and truck parts, medical and aerospace components and the like, relied on sampling inspection of threads using hand gages. But in the last dozen years, with an accelerated trend toward automated assembly; and with increased outsourcing of machined parts, it has become more urgent for them to move toward automated 100% thread gaging for many critical components.