* Material: Inner tube stainless steel 316L, 316L VAR, Outer tube 316L, 304L
* Inner tube outside diameters from 1/4″ to 2″, outer tube from 1/2″ to 2 1/2″
* Machined from forging blanks except for straight configurations
* Inner tube: internal surface electropolished to roughness of Ra≤5 μin (0.13 μm), Ra≤7 μin (0.18 μm), Ra≤10 μin (0.25 μm)
* Outer tube: internal surface bright annealed or bright annealed after precision cold working to roughness of 15 μin (0.38 μm),
Ra≤20 μin (0.51 μm),