Copper Parts and Fabrication in Nampa, ID — C101, C110, and Tellurium Copper for Electrical and Thermal Applications

C110 electrolytic tough pitch copper (ETP, UNS C11000) is the standard for electrical applications — bus bars, transformer windings, motor commutators, switch gear contacts, and grounding systems. Its minimum 99.9% copper content and nominal electrical conductivity of 101% IACS (International Annealed Copper Standard) make it the benchmark against which all copper alloys are measured. In Nampa's construction and industrial context, C110 shows up in switchgear bus bar fabrications for commercial and industrial facilities, in grounding grid connections for agricultural facilities with high-voltage equipment, and in heat-sink and cold-plate assemblies for the Treasure Valley's expanding industrial electronics manufacturing. C101 oxygen-free copper (OFHC, UNS C10100) steps up where C110 is not sufficient: when the part will be exposed to hydrogen atmospheres at elevated temperatures (where the oxygen in ETP copper causes hydrogen embrittlement and blistering), when ultrahigh vacuum applications require the lowest possible outgassing rate, or when electronic/RF applications demand the absolute minimum resistivity. C101's 99.99% minimum purity gives it 101% IACS conductivity like C110 but eliminates the oxygen inclusion risk entirely. In Nampa, C101 is the call for precision RF shield components, vacuum-compatible heat-transfer parts, and any copper component that will be brazed in a hydrogen or reducing atmosphere furnace. Fabrication of C110 bus bar is a bread-and-butter capability for Nampa's industrial sheet metal and structural shops. Standard C110 bus bar is available in flat bar from 0.25 × 1 in. up to 0.5 × 6 in. and can be cut, punched, drilled, bent, and silver-plated at local shops. Joint contact surfaces should be machined or faced to Ra 63 µin. or better for reliable low-resistance bolted connections — rough surfaces increase contact resistance and create hot spots under load.

Pure C110 and C101 copper are notoriously difficult to machine — their high ductility produces long, stringy chips that wrap around tools, their softness causes workpiece deformation under cutting forces, and their tendency to stick to tool rake faces creates built-up edge that destroys surface finish. Tellurium copper C145 (UNS C14500, 0.4–0.7% tellurium addition) solves this problem decisively: tellurium forms copper telluride particles at grain boundaries that act as chip breakers, transforming the machining behavior from nightmare to one of the most machinable metals in the catalog — machinability rating of 90% versus 20% for C110. C145 retains approximately 93–95% of C110's electrical conductivity while delivering dramatically shorter, well-controlled chips, smooth surface finishes (Ra 32–63 µin. achievable with standard carbide tooling), and consistent dimensional control on tight-tolerance bores and threads. Nampa CNC shops specify C145 for precision electrical connectors, terminal blocks, switch contacts, current-carrying pins, electrode bodies, and any copper part with complex machined geometry where maintaining conductivity while achieving tight tolerances is the engineering brief. Thread milling in C145 produces far more reliable results than tapping in C110 — the controlled chip formation prevents tap binding and cross-threading that plague pure copper tapping operations. For high-volume connector machining, Nampa shops running C145 bar in Swiss-style CNC lathes can achieve ±0.0005 in. diameter tolerances on connector pins at production rates comparable to free-machining brass — a dramatic productivity improvement over attempting the same geometry in C110. Tin plating (0.0001–0.0003 in.) is the standard finish for electrical connectors made from C145, providing solderability and preventing copper oxide formation at mating surfaces.

The thermal conductivity advantage of copper over aluminum (226 vs. 110 BTU/hr·ft·°F) and stainless steel (226 vs. 9 BTU/hr·ft·°F) makes it the preferred material for heat exchanger surfaces, cold plates, and conductive heat spreaders where thermal performance is the design constraint. In Nampa's agricultural processing equipment sector — where blanching systems, pasteurizers, and refrigeration heat exchangers are standard equipment — copper tube and plate heat exchangers are the thermal design standard for all but the most chemically aggressive process streams. Copper tube for heat exchanger service is governed by ASTM B75 (seamless tube, C110) and ASTM B111 (condenser and heat exchanger tube). Common OD/wall combinations stocked in the Boise-area market run from 3/8 OD × 0.032 wall through 1.5 OD × 0.065 wall in straight lengths and coils. Nampa fabricators building agricultural heat exchangers typically solder or braze tube-to-header joints with 45% silver solder (BAg-5 or BAg-7) for food-adjacent applications where lead-free joints are required, or with 15% silver phos-copper alloy (BCuP-3) for lower-cost industrial refrigeration service. For cold-plate assemblies in electronic cooling or precision temperature control applications, Nampa shops machine C110 plate to net geometry, drill internal coolant channels (typically 0.375–0.75 in. diameter) with gun drills capable of holding straightness within 0.002 in./in. over 12+ inches of depth, and braze cover plates or press-fit fittings to complete the fluid circuit. Surface flatness of the cold contact face is typically specified at 0.001–0.003 in. over the full face area to ensure thermal contact with the mating heat-generating component.

Copper pricing is commodity-linked to LME (London Metal Exchange) spot prices in a way that most other machining materials are not. When buyers request copper parts quotes, the price quoted is valid for a limited window — typically 5–15 business days — because shop material costs track copper spot, which can swing 5–10% in a matter of weeks during volatile commodity cycles. Buyers planning production programs with copper components should discuss pricing escalation clauses or commodity-index pricing mechanisms with Nampa suppliers for contracts running more than 60 days, rather than expecting a fixed price for the program duration. C110 and C145 round bar are regularly stocked by Boise-area metal service centers in diameters from 0.25 in. through 4 in. Flat bar, plate, and bus bar in C110 are similarly accessible with 1–5 day lead times on standard sizes. C101 OFHC is a specialty item that typically requires 1–2 weeks from distributors with OFHC stock, which is a subset of the regional distributors. C145 is well-stocked due to its high demand in precision machining; most Nampa CNC shops maintain a standing stock of C145 bar in the common Swiss-lathe diameters (0.25–2 in.) to support fast-turn connector and terminal work. For plated copper parts — tin, silver, or gold plating on electrical connectors and contacts — Nampa buyers have access to several Boise-metro plating houses that specialize in functional electrical plating. Silver plating (0.0001–0.001 in.) on bus bar contact faces and C145 connectors is a common local service, with 3–5 day turnaround on production quantities. ManufacturingBase's supplier profiles identify which Nampa machining shops have in-house plating capability versus those that subcontract, and which plating vendors in the region are qualified for aerospace or military plating specifications (QQ-S-365, AMS 2410) versus commercial-grade work only.