All ASTM D3241 heater tubes start out the same way - as 6061-T6 aluminum that meets very specific chemical composition limits as outlined in ASTM D3241. The aluminum is drawn into tubing and machined to near final dimensions using high-precision CNC machines. Production tolerances are less than 0.0005 inch (0.01 mm).
The material and dimensions of Standard ASTM D3241 Heater Tubes comply with all of the requirements listed in ASTM D3241.
Standard ASTM D3241 Heater Tubes are finished using a patented process that produces an extremely high-quality surface finish on the heater tube. This finish meets the requirements of ASTM D3241.
The fine finish of the Standard ASTM D3241 Heater Tube makes it much easier to see and rate tube deposits.
Standard ASTM D3241 Heater Tubes can also be rated using automated tube readers that use interferometry and ellipsometry techniques.