1. Standard & Practices: To comply with all requirements of ASTM A254
2. Hardness: (On ID 90 degree from Seam) Rockwell 30T 55 Maximum.
3. Flatten & Bend Test: A section of the tubing 2-1/2″ minimum long shall stand being flattened between parallel plates until the inside walls are in contact. The flattened section shall then be bent once through 90 degree around a pin having a diameter three times the wall thickness of the tubing, and shall be subsequently straightened once without cracking or showing flaws.
4. Tolerances:
| Permissible Variation | ||
| Plus | Minus | |
| OD 3/16″ | .002″ | .002″ |
| OD 1/4″ & Over | .002″ | .003″ |
| Wall Thickness1 | .002″ | .003″ |
1For .020″ to .049″ thick walls.
5. Hydro-static Test: To withstand, without leaking, an internal hydro-static pressure sufficient to subject the material to a minimum fiber stress of 16000 psi. Hydro static pressure shall be determined by the following equation:
P=2St/D
Where
P = hydrostatic pressure in psi
S = alloable fiber stress, 16000 psi
t = wall thickness of tubing in inches
D = outside diameter of tubing in inches.