Schedule 40 pipe question 1

Old time terminology.
The pipe scheduals are roughly based on the ID of 'std' pipe. Other walls (sch) are fractions of the std.

If you start working with pipe make sure that you also know the tolerances. Read the specs carefully.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

ASME B36.10M-2004, WELDED AND SEAMLESS WROUGHT STEEL PIPE

"The original intent of the Committee was to establish a system of Schedule Numbers for pipe size/wall thickness combinations which would have an approximately uniform relationship equal to 1000 times the P/S expression contained in the modified Barlow formula for pipe wall thickness as defined in the Appendix to this standard. The resulting Numbers departed so far from existing wall thicknesses in common use that the original intent could not be accomplished. The Schedule Numbers were then adopted strictly as a convenient designation system for...”