I am trying to convert some Metric pipe to SAE pipe, and I do not understand the callout/description.
"Tube OD 139.7 SP. 1.5 L=2090"
The question I have is the "SP. 1.5" Does anyone know what this means? I checked the all-knowing internet, and it told me that the wall thickness is designated by DIN much the same as we use a schedule number.
Thanks in advance for any help you can offer.

Carl