A "DD" rivet, often also referred to as a "D" rivet, is commonly called an icebox rivet due to its heat treatment requirements. These rivets must undergo a heat treating process before they can be used effectively. After heat treatment, they must be stored in a freezer and driven within a short timeframe, typically no more than 20 minutes, to maintain their malleable state for proper installation.
Why the Heat Treatment and Freezing?
The heat treatment process softens the rivet, making it easier to deform during installation. Freezing the rivet after heat treatment significantly slows down the age-hardening process, keeping it soft and pliable for the relatively short window necessary for successful riveting. The 20-minute timeframe is critical because the rivet will gradually harden at room temperature, making it difficult, if not impossible, to properly deform and set.
Key Characteristics of DD Rivets:
- Material: Often made from aluminum alloys.
- Heat Treatment: Required to soften the rivet.
- Freezing: Necessary to maintain the softened state.
- Short Working Time: Must be installed within approximately 20 minutes after removal from the freezer.
- Common Name: Icebox rivet.
Applications:
While the reference suggests "icebox rivets," DD rivets (along with "D" rivets which undergo a similar process) are more broadly used in aerospace and other applications where a strong, flush, and reliable fastening solution is needed and where the rivet material must be easily deformed.
