The check
Runs in your browser. Pick the code and the size.
The rules it applies
Markings. AC 43.13-1B Table 4-8: 1100 plain (A), 2117-T dimpled (AD), 2017-T raised dot (D), 2024-T raised double dash (DD), 5056-T raised cross (B).
Icebox. Paragraph 4-57d: “The 2117 rivets may be driven in the condition received, but 2017 rivets above 3/16 inch in diameter and all 2024 rivets are to be kept packed in dry ice or refrigerated in the ‘quenched’ condition until driven, or be reheat treated just prior to driving, as they would otherwise be too hard for satisfactory riveting.”
Substitution. Paragraph 4-57b: it is acceptable to replace 2017 rivets of 3/16 in or less, and 2024 rivets of 5/32 in or less, with 2117 rivets for general repairs, provided they are 1/32 in larger in diameter.
The AC gives no time limit for how long an icebox rivet stays drivable once out of the cold. The figures in circulation come from elsewhere; this check does not use them.
Worked example
A drawing calls for MS20470DD4 (2024, 1/8 in) in a general repair.
- 2024: icebox rivet, kept refrigerated in the quenched condition until driven.
- 1/8 in is under 5/32 in, so 4-57b allows a 5/32 in 2117 rivet instead, if edge distance and pitch allow it.
Either an icebox DD4, or an AD5 if the layout takes 5/32 in.
Limits — when NOT to use this
- Approved data governs the rivet alloy and whether a substitution is allowed.
- General repairs only for the 2117 substitution (AC 4-57b).
- Edge distance and pitch grow with the larger substitute rivet; check them.
Questions people actually ask
How long can a DD rivet stay out of the freezer?
AC 43.13-1B gives no figure: it says keep them cold until driven or reheat treat them. Use your process specification's limit if it has one.
Sources
- FAA AC 43.13-1B CHG 1, Chapter 4, Table 4-8, par. 4-57b and 4-57d — head markings and material codes; icebox condition; the 2117 substitution at +1/32 in.