CR for Caltrops and related equipment

[Murdock Mudeater]

Designing an encounter where caltrops are spread over the area (as area denial), do the caltrops have any CR of their own? How do you handle the CR similar equipment?

[Java Man]

I give caltrops the same CR as the axe the orc is holding. Both are part of the enemy's gear allotment.

[Murdock Mudeater]

That works, just doublechecking.