Aluminum 4" Female NPT to 2 1/2" Male NH Storz Size_2 1/2" Rigid Storz National Pipe Tapered is common

National Pipe Tapered is common in plumbing and some industrial uses

however there are "local" exceptions

Kochek adjustable fire hydrant wrench with double head spanner for pentagon and square heads

Equivalent part number - HA30S25F

Aluminum 4" Female NPT to 2 1/2" Male NH Storz Size_2 1/2" Rigid Storz National Pipe Tapered is commonAluminum adapters are fabricated from seamless extruded 6061 T6 aluminum and hard coat anodized per MIL A 8625 Type III, Class 1. Threads have a blunt start Higbee cut with indicators on adjacent lugs. Part identifications are permanent and stamped prior to hardcoat. Adapters and components meet the requirements of NFPA 1963. The Safe Water Drinking Act section 1417 requires "Lead Free" products to be a minimum of 99. 75% lead free. Aluminum Female to