Not sure what your question is.
If you talking a tool to loosen and tighten an F connector, that would not have anything to do w/ a loss of signal.
If you talking a type of F connector, then yes, there are cheap ones that will even fall off the cable if you turn your back on them. I like using the o-ring sealed ones that the cable guys use,.....which requires a special tool to collapse the sleeve that seals the conn to the coax.
And if you install very many F connectors, buying a coax stripping tool, is worth its weight in gold. I can't believe how good they work !