A "Stillson" in these parts. Strict, it's a "Stillson pattern spanner" only if it's in this pattern:
Otherwise it's an "adjustable spanner" or just a 'justie.
Here, that's just called a
Pipe Wrench. I don't know of any commonly used commercial tradenames for them.
Old, established companies like Ridgid have been making them for 100 years, but we don't normally call them a Ridgid or a Stillson.
An adjustable wrench could be of MANY types, when I ask for a Crescent Wrench, I want that style, not a pipe wrench (which is also adjustable) or a monkey wrench (which is also adjustable) etc.
If I just say "hand me an adjustable," what do I mean? A basin wrench? A pipe wrench? A monkey wrench?
Maybe some CHAN
NELLOCKs?! (No, because those are types of PLIERS!! Not to be confused with slip-joint, needle-nose, linesman, etc!)
No, I want you to hand me the
Crescent Wrench, a specific type of adjustable...
That big 12" one, over there by the axle housing....