NPS 4 Pipe

Outside diameter 4.500″

OD in mm 114.3 mm

Every NPS 4 pipe has this OD regardless of schedule — the schedule changes only the wall thickness and bore.

Schedules

Schedule	Wall	Wall mm	Inside diameter	ID mm
40 = STD	0.237″	6.02	4.026″	102.26
80 = XS	0.337″	8.56	3.826″	97.18

Data provenance. ASME B36.10M, Welded and Seamless Wrought Steel Pipe (Table 2.1) (ASME). ID is derived: OD − 2 × wall. Dimensions are nominal; actual walls carry the standard's mill tolerance. See all data sources.