If it's stuck use WD-40
Bolts will usually break first if twisted enough.
How is a nut like a bolt
When an object is heated, it will expand. When cooled it will contract. So if you quickly heat and cool a stuck nut and bolt, it can break apart the rust or whatever is causing it to stick.
A bolt without a nut or a head is called a stud.
The owners manual shows 100 lb.ft. ( with nut and bolt threads free of dirt and rust )
it is stuck use a brass punch so you do not damage threads hit it a couple times should break free.
you use a spanner to open a rusted nut bolt because you need a strong tool to open a rusted nut bolt.
A nut and bolt combination forms a fastener .
A lock nut should go on a bolt before a washer or the nut.
Gauges to allow a person to calculate nut bolt size are widely available. Measuring the thread manually can be unreliable so it is far preferable to use a gauge.
screw
A nut and bolt combination forms a fastener .