Aluminum CNC Machining and Supply in Boise, ID

For most semiconductor handling and metrology fixtures, 6061-T6 is the default and best-value choice. It is non-magnetic, dimensionally stable, and machines to tight tolerances cleanly, which matters when you are holding +/-0.001 inch on locating features. If the part is large and flatness is critical, ask your Boise supplier for stress-relieved cast tooling plate (Mic-6 / ATP-5) instead of standard rolled 6061, because rolled plate can release internal stress during machining and warp out of tolerance. For high-load fixtures that see repeated clamping or impact, step up to 7075-T73, which nearly doubles the yield strength while resisting stress-corrosion cracking. Finish-wise, Type III hardcoat anodize is common on wear surfaces, and chromate conversion coating is used where you need surface conductivity. Always request mill certs traceable to the heat lot, especially if the fixture touches process-critical product.

Most Boise CNC shops machine in-house and partner with regional anodizing lines rather than running their own anodize tanks, so the shop manages the finishing logistics for you under one PO. The Treasure Valley has enough plating and anodizing capacity to support Type II decorative, Type III hardcoat, and chromate conversion within typical lead times. When you request a quote, specify the anodize type, color, and thickness up front, because that drives masking, racking, and tolerance compensation, anodize adds thickness (roughly 0.0005 to 0.002 inch on hardcoat per surface) that the shop must account for on close-tolerance bores. The advantage of letting one Boise shop own machining plus finishing is single-point accountability: if a cosmetic part comes back with anodize blemishes or a mismatched color batch, you have one vendor to resolve it rather than a finger-pointing match between machinist and finisher.

The short answer is strength versus economy. 6061-T6 runs around 45 ksi tensile and 40 ksi yield, welds and anodizes beautifully, and costs noticeably less, so it handles the majority of housings, plates, and brackets. 7075-T73 runs around 73 ksi tensile, making it the choice when a part is load-bearing, fatigue-stressed, or a precision fixture that cannot flex. The trade-offs: 7075 is not readily weldable, it is more expensive, and standard 7075-T6 is prone to stress-corrosion cracking, which is why the T73 temper (slightly lower strength, far better SCC resistance) is preferred for tooling that lives for years. For Boise's recreation OEMs, 6061 covers most frame and hardware needs; for aerospace-defense brackets and heavy-duty jigs, 7075-T73 is worth the premium. A good supplier will tell you when a print over-specifies 7075 for a part that 6061 would serve fine.

Yes. 5052 is a staple for sheet-metal enclosures, fluid components, and formed brackets, and Boise-area metal suppliers and fab shops typically stock it in common gauges from roughly 0.040 to 0.125 inch. Its strength comes from the non-heat-treatable magnesium alloying, which gives it excellent corrosion resistance (it was originally developed for marine use) and outstanding formability, so it bends to tight radii without cracking, unlike 6061 which can split on sharp bends. That makes 5052 the right pick for chassis, brackets, and panels that need forming, welding, and a clean painted or powder-coated finish. If your enclosure needs to be machined more than formed, or needs higher strength, 6061 may be the better base, but for sheet-metal work with bends, request 5052-H32. Lead times on stocked gauges are usually short; non-standard thicknesses or large sheet sizes may require a mill order.

Flatness problems almost always trace back to residual stress in the raw material, not the machinist. Standard rolled or extruded aluminum carries internal stresses from manufacturing; when you remove material asymmetrically, those stresses redistribute and the part bows or twists, sometimes days after machining. To avoid it on Boise jobs, specify stress-relieved cast tooling plate (Mic-6, ATP-5, or K100-S) for any large flat part, plate, baseplate, or optical fixture, because it is cast and stress-relieved to be dimensionally stable. For parts machined from standard stock, ask the shop to rough machine, then stress-relieve or let the part normalize before finishing critical surfaces, and to balance material removal across both faces where possible. Confirm flatness expectations in the print (for example, 0.002 inch over 12 inches) so the shop quotes the right process. CMM or surface-plate verification before shipment gives you documented proof the part met spec when it left.