COLUMBUS, Ohio – October 28, 2026 -- The same busbar drawing can produce supplier quotes up to three times apart, depending on which manufacturing process each supplier assumes, according to engineering guidance released by MES, Inc. The guidance targets data center engineers and sourcing teams specifying copper and aluminum busbar for high-density power distribution.
Liquid-cooled AI racks push current above 2,000 amps
A liquid-cooled AI rack can draw around 120 kW. At the 48 to 54 V DC used inside many of these racks, that exceeds 2,000 amps. Busbar is therefore a critical component inside the rack and in the switchgear and busway that feed it.
MES President and CEO Hiten Shah said material and margin do not explain the quote gap. One supplier prices punch and bend, another stamping, another machining, so buyers are not comparing the same part until those assumptions are disclosed.
Volume breakpoints separate machining, punch and bend, and stamping
MES outlines general breakpoints for four common processes:
- CNC machining is often the lowest total-cost option below about 200 pieces a year.
- CNC punch and bend typically leads from roughly 200 to 5,000 pieces.
- Stamping becomes increasingly competitive above about 10,000 pieces, as tooling costs spread across larger runs.
- Extrusion fits long aluminum busbar with a constant cross-section.
Part complexity, number of variants and design stability can all move these breakpoints.
Tight tolerances belong at the electrical joint only
The guidance recommends roughly 0.05 mm flatness across bolted contact areas and about ±0.10 mm position on critical bolt patterns, with standard tolerances elsewhere. Applying tight tolerances across the whole part can force a move to machining without improving performance.
Deburring leaves rollover and work-hardened material on insulated busbar
Deburring removes the burr on punched and stamped edges but not rollover, fracture zones or work-hardened material. Powder and epoxy coatings can thin at sharp edges, where electric fields also concentrate.
Brad Layne, Engineering Manager at MES, said edge radius is among the most common gaps on insulated busbar drawings. Without a specified radius, edge condition depends on the supplier's process choice.
MES specifies 6101 aluminum over 6063 for extruded current-carrying busbar
For extruded, current-carrying busbar, the guidance calls for 6101 aluminum rather than structural alloy 6063. Alloy 6101 is available with minimum conductivity requirements under ASTM B317.
MES supplies copper and aluminum busbar through a manufacturing network spanning eight countries, covering CNC punch and bend, stamping, machining and extrusion. Its engineering team reviews drawings before tooling begins to identify the most practical manufacturing route. The guidance includes a busbar drawing and RFQ checklist.