A key reason engineers keep the on their desk is the cross-reference matrix to international standards.
Switching from copper to aluminium requires a design philosophy shift. Aluminium expands twice as much as copper (Coefficient of linear expansion: 23 x 10^-6 /K vs 17 x 10^-6 /K). Ignoring this leads to creep and joint failure. Indal Handbook For Aluminium Busbar
| Symptom | Likely Cause | Solution per Handbook | | :--- | :--- | :--- | | Hot spot at joint (ΔT > 20°C) | Oxide layer not broken before assembly | Disassemble, re-abrade, re-apply compound. | | Black powdery residue | Galvanic corrosion (copper bolt used) | Replace hardware with stainless steel. | | Loose bolts after 1 year | Creep due to over-torque initially | Re-torque to spec; replace washers if flattened. | | Cracking near bolt hole | Hole drilled too close to edge ( <1.5x diameter) | Use repair plate or replace bar. | | High resistance reading | Grease contaminated with dust | Clean, apply fresh zinc-filled grease. | A key reason engineers keep the on their
Precise pressure requirements for bolted joints to manage aluminium’s tendency to "cold flow" or creep under stress. Ignoring this leads to creep and joint failure