Magnesium Suppliers and Machining Partners in Cedar Rapids, IA

Magnesium sits at roughly 1.74 g/cm3, about two-thirds the density of aluminum and a quarter that of steel. For Collins Aerospace avionics enclosures and the chassis-level brackets that surround them, that translates directly into fuel burn and payload, which is why AZ31B and the high-performance WE43 alloy keep showing up on aerospace prints in this region. The metal also damps vibration well, a property that matters in airborne electronics housings exposed to constant airframe excitation. The local food-processing and ag-equipment shops have a different angle. They tend to use die-cast AZ91D for housings, covers, and handheld tool bodies where a one-piece casting replaces a multi-part aluminum or steel assembly. The casting fluidity of magnesium lets these shops hold thin walls down near 1.5 mm, cutting part count and assembly labor on equipment that ships in volume. The trade-off is corrosion: bare magnesium in a wash-down food environment needs a chromate or anodize-type conversion coating, and buyers should spec that finish up front rather than discover it during qualification.

AZ31B is the workhorse wrought grade, sold as sheet, plate, and extrusion. It bends and forms reasonably well, machines cleanly, and welds with the right shielding. Cedar Rapids fabricators handling avionics brackets and lightweight structural panels reach for AZ31B-H24 when they need a temper that holds shape. Expect a tensile strength around 260 MPa and good response to forming at moderate temperatures. AZ91D is the dominant die-casting alloy, with about 9 percent aluminum and 1 percent zinc. It offers the best castability and corrosion resistance of the common AZ family, and the 'D' designation specifies tight limits on iron, nickel, and copper to keep galvanic corrosion in check. It is the right call for housings and covers produced in quantity. WE43 is the specialty grade. Alloyed with yttrium and rare earths, it retains strength up to roughly 250 C, far beyond what AZ alloys tolerate, which puts it on aerospace gearbox housings and high-temperature avionics components. It is more expensive and harder to source, so confirm material certs and lead time early. For any of these, ask the supplier for the mill certificate tied to the heat lot, especially on WE43 where rare-earth content drives performance.

Magnesium machines fast, faster than aluminum, with low cutting forces and excellent surface finishes. The catch is that fine chips and dust ignite, and a magnesium fire cannot be put out with water. A shop that runs magnesium routinely keeps Class D extinguishers on hand, controls chip accumulation, and often runs dry or with mineral-oil-based coolant rather than water-based fluid. When you qualify a Cedar Rapids machining partner for magnesium, ask directly how they handle chips and what coolant they use. Because many local shops are tooled primarily for aluminum and steel feeding the ag and aerospace base, not every CNC house is set up for magnesium. The ones that are can hold avionics tolerances comfortably, often plus or minus 0.001 inch on critical features, and deliver finishes that need minimal secondary work. Pair that machining capability with a conversion-coating or paint line so the bare metal does not sit unprotected, since magnesium will corrode quickly in Iowa humidity if left raw.

Corrosion is the single biggest reason magnesium parts fail in service, and it is entirely manageable with the right process. The standard path is a chromate conversion coat per the relevant aerospace or commercial spec, followed by primer and topcoat for parts exposed to weather or wash-down. For avionics enclosures that need EMI shielding plus corrosion protection, conductive conversion coatings preserve grounding while protecting the substrate. Joining magnesium is doable but demands care. TIG welding AZ31B works with argon shielding and matching filler, common in the welding-fabrication capability already strong across Cedar Rapids shops. Where you mix magnesium against steel or aluminum fasteners, isolate the joint with coatings, washers, or sealants to break the galvanic couple, or magnesium being anodic to nearly everything will sacrifice itself. Spec fastener materials and isolation on the drawing so the assembly shop does not improvise.