Mechanical fasteners (mostly bolts) tend to have a threaded section protruding from their nut, beyond the usual three or four threads, when the bolt has been tightened to the correct specification.
This occurs because bolts need to be manufactured to certain standardised sizes and this includes lengths.
However, it does mean that in applications where excess weight is critical (eg aircraft, racing cars, spacecraft) a large excess mass is being carried which decreases performance.
As an example, there are ~1M fasteners on a 777 airliner.
Let’s say that half of these are external threaded types and that each of those has an excess threaded portion of 2mm of steel. This represents (for, say, M6 bolts) a waste of $11000 per year per airliner (based on the rule of thumb of $50/kg.
Today’s invention is a bolt cutter incorporated into a torque wrench, so that, when a bolt has been tightened, any excess over, say, three protruding threads can be swiftly removed.
