Federal regulations · Through 2026-08-25 · Newer source version available

49 CFR 178.346-2: -2 Material and thickness of material.

The type and thickness of material for DOT 406 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.
Table 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
Material Volume capacity in gallons per inch of length
14 or less Over 14 to 23 Over 23
MS HSLA SS AL MS HSLA SS AL MS HSLA SS AL
Thickness .100 .100 .160 .115 .115 .173 .129 .129 .187
Table 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 1
Cargo tank motor vehicle rated capacity (gallons) MS SS/HSLA AL
More than 0 to at least 4,500 0.100 0.100 0.151
More than 4,500 to at least 8,000 0.115 0.100 0.160
More than 8,000 to at least 14,000 0.129 0.129 0.173
More than 14,000 0.143 0.143 0.187
1 Maximum distance between bulkheads, baffles, or ring stiffeners shall not exceed 60 inches.

Where this section sits in the code

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

Table 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

Material Volume capacity in gallons per inch of length

14 or less Over 14 to 23 Over 23

MS HSLA SS AL MS HSLA SS AL MS HSLA SS AL

Thickness .100 .100 .160 .115 .115 .173 .129 .129 .187

Table 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 1

Cargo tank motor vehicle rated capacity (gallons) MS SS/HSLA AL

More than 0 to at least 4,500 0.100 0.100 0.151

More than 4,500 to at least 8,000 0.115 0.100 0.160

More than 8,000 to at least 14,000 0.129 0.129 0.173

More than 14,000 0.143 0.143 0.187

1 Maximum distance between bulkheads, baffles, or ring stiffeners shall not exceed 60 inches.

Collected 2026-08-27T02:26:34Z. Source file · JSON

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