Discussion Overview
The discussion revolves around the behavior of bolts when torqued to a specified torque and whether they return to the same position upon refastening. Participants explore the implications of material properties, deformation, and the definitions of bolts versus screws, as well as historical practices related to retorquing head bolts.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- Some participants suggest that if parts are very stiff, the markings may align upon refastening, while others argue that softer materials may undergo permanent deformation, preventing alignment.
- There is a discussion about the definition of bolts versus screws, with some asserting that a bolt requires a nut, while others challenge this definition.
- Concerns are raised about the wear on threads and contact surfaces over multiple cycles, which could affect alignment.
- Some participants mention that cylinder head bolts are often specified for one-time use due to the risk of failure upon re-torquing.
- A participant shares a specific procedure used in aviation for ensuring proper alignment when using castellated nuts and cotter pins, highlighting different practices in various contexts.
- There is a humorous exchange regarding terminology and variations in fastener names across regions, indicating a broader discussion about language and definitions in engineering.
Areas of Agreement / Disagreement
Participants express differing views on whether bolts will return to the same position upon refastening, with some asserting it is possible under certain conditions while others highlight factors that may prevent this. The discussion remains unresolved regarding the definitions and implications of using bolts versus screws.
Contextual Notes
Participants note that factors such as temperature, lubrication, and cleanliness of surfaces can influence the outcome of torque applications, but these aspects are not fully resolved within the discussion.