{"data":{"id":"us/49-cfr-178.348-2","jurisdiction":"us","citation":"49 CFR 178.348-2","heading":"-2 Material and thickness of material.","body":"(a) The type and thickness of material for DOT 412 specification cargo tanks must conform to § 178.345-2, but in no case may the thickness be less than that determined by the minimum thickness requirements in § 178.320(a). The following Tables I and II identify the “Specified Minimum Thickness” values to be employed in that determination.\nTable I—Specified Minimum Thickness of Heads (or Bulkheads and Baffles When Used as Tank Reinforcement) Using Mild Steel (MS), High Strength Low Alloy Steel (HSLA), Austenitic Stainless Steel (SS), or Aluminum (AL)—Expressed in Decimals of an Inch After Forming\nVolume capacity (gallons per inch) 10 or less Over 10 to 14 Over 14 to 18 18 and over\nLading density at 60 °F in pounds per gallon 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs Over 16 lbs 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs Over 16 lbs 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs\nThickness (inch), steel .100 .129 .157 .187 .129 .157 .187 .250 .157 .250 .250 .157 .250 .312\nThickness (inch), aluminum .144 .187 .227 .270 .187 .227 .270 .360 .227 .360 .360 .227 .360 .450\nTable II—Specified Minimum Thickness of Shell Using Mild Steel (MS), High Strength Low Alloy Steel (HSLA), Austenitic Stainless Steel (SS), or Aluminum (AL)—Expressed in Decimals of an Inch After Forming\nVolume capacity in gallons per inch 10 or less Over 10 to 14 Over 14 to 18 18 and over\nLading density at 60 °F in pounds per gallon 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs Over 16 lbs 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs Over 16 lbs 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs 10 lbs and less Over 10 to 13 lbs Over 13 to 16 lbs\nThickness (steel):\nDistances between heads (and bulkheads baffles and ring stiffeners when used as tank reinforcement):\n36 in. or less .100 .129 .157 .187 .100 .129 .157 .187 .100 .129 .157 .129 .157 .187\nOver 36 in. to 54 inches .100 .129 .157 .187 .100 .129 .157 .187 .129 .157 .187 .157 .250 .250\nOver 54 in. to 60 inches .100 .129 .157 .187 .129 .157 .187 .250 .157 .250 .250 .187 .250 .312\nThickness (aluminum):\nDistances between heads (and bulkheads baffles and ring stiffeners when used as tank reinforcement):\n36 in. or less .144 .187 .227 .270 .144 .187 .227 .270 .144 .187 .227 .187 .227 .270\nOver 36 in. to 54 inches .144 .187 .227 .270 .144 .187 .227 .270 .187 .227 .270 .157 .360 .360\nOver 54 in. to 60 inches .144 .187 .227 .270 .187 .227 .270 .360 .227 .360 .360 .270 .360 .450\n(b) [Reserved]","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—HAZARDOUS MATERIALS REGULATIONS","PART 178—SPECIFICATIONS FOR PACKAGINGS","Subpart J—Specifications for Containers for Motor Vehicle Transportation"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"79a21293c4679454295cbb6d66cd15585f4092677db59fb7cbd6075027d417f1","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-178.348-1","next":"us/49-cfr-178.348-3"},"notice":"GroundRules: Original legal text. Not legal advice."}