Structural Bolts
Aerospace-Grade Preloaded Bolt Assemblies
Aerospace-grade preloaded bolt assemblies are high-strength fasteners fabricated from A286 stainless steel, Inconel 718, or Ti-6Al-4V to provide clamped structural connections throughout the Ark assembly. With a thread engagement length of at least 1.5 times the bolt diameter, each bolt provides a controlled preload ensuring joint clamping force exceeds service loads. The lunar vacuum introduces severe galling risks for titanium components, necessitating anti-galling coatings such as silver plating or molybdenum disulfide. Additionally, joints must accommodate preload relaxation across 100 years of thermal cycling using hex socket heads suited for robotic installation and bolt-stretch measurement.
High-strength bolts providing preloaded structural connections throughout Ark assembly
Purpose
High-strength bolts providing preloaded structural connections throughout Ark assembly
Context
Child of L2-STR-FAST
Principles
- ▸Controlled preload (torque or tension) ensures joint clamp force exceeds service loads
- ▸Bolt material selection (A286, Inconel 718, Ti-6Al-4V) matched to joint materials and loads
- ▸Thread engagement length minimum 1.5x bolt diameter for full thread strength development
- ▸Bolt stretch measurement verifies correct preload during robotic installation
Typical implementations
- ▸NAS 6200 series aerospace structural bolts
- ▸ASTM A574 socket head cap screws for space
- ▸Huck aerospace lockbolts for permanent joints
Lunar considerations
- ▸Anti-galling coating (silver, MoS2) essential for titanium bolts in vacuum
- ▸Preload relaxation over 100 years from thermal cycling must be accounted in design
- ▸Robotic-compatible bolt heads (hex socket) for autonomous maintenance
Specifications
Functional
| primary function | High-strength bolts providing preloaded structural connections throughout Ark assembly |
Physical
| materials | A286 stainless steel bolts, Ti-6Al-4V bolts, Inconel 718 bolts, Silver-plated finish |
Interfaces
Provides
- Preloaded structural connections
Requires
- Replacement bolt manufacturing
Cite this entry
Lunar Ark Codex. "Structural Bolts" (L3-STR-FAST-BOLT). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-STR-FAST-BOLT
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.