Is it just like a larger version of a earring backing?
No its definitely not. For one thing the ‘commercial findings’ type
has a steel spring that bites into the post, said post being much
thicker than an earring post. If anything its more like those Alpha
System earring parts, except the Alpha has a grooved post to accept
the ‘grippers’. A tie tac back doesn’t want a groove because ties
come in various thicknesses, so you need some adaptability. The
other thing is the regular tie tac backs covert he point of the post.
No chance of being stabbed in the sternum.
Oh and one more thing…those backs are forever being lost and
replaced…just go with the commercial version, plenty cheap and no
head (or chest) aches. I’ve never met anyone who objected to them
not being karat gold.