Magnesium Machining and Fabrication in Green Bay, WI

Northeast Wisconsin's heavy-equipment sector puts a premium on mass reduction without sacrificing rigidity. A gearbox housing machined from AZ91D magnesium die-cast alloy weighs roughly 30 percent less than the equivalent aluminum A380 casting — and that delta matters when a machine runs continuously on a paper mill floor or a construction equipment assembly line. Local CNC shops running 4- and 5-axis Mazak and Haas centers handle AZ91D effectively when coolant selection and chip management protocols are dialed in, since magnesium swarf is combustible and requires non-aqueous or properly inhibited coolant systems. For wrought applications — plate, sheet, and bar stock that gets machined rather than cast — AZ31B is the workhorse grade. It machines at surface speeds up to 1,000 SFM with sharp carbide tooling, producing tight tolerances in the +/-0.001 inch range that bracket and frame work requires. Green Bay shops familiar with aluminum fixturing adapt quickly; the workholding approaches are similar, but clamping pressure must be controlled to avoid crushing the lower-density material. Anodizing and chemical conversion coatings protect finished parts against the humidity and salt exposure common in Wisconsin's climate.

Choosing between magnesium grades comes down to the production method and the service environment. AZ31B — a wrought alloy with roughly 3 percent aluminum and 1 percent zinc — is the standard choice for machined plate and extruded profiles. Its elongation of 15 percent at room temperature gives it enough ductility for flanged brackets and formed enclosures used in packaging and food processing machinery built in the Green Bay area. AZ91D is the die-cast standard, with higher aluminum content (9 percent) that improves castability and yield strength to approximately 23 ksi. It is the preferred grade for complex, thin-wall housings where casting is more economical than machining from billet. WE43 is a rare-earth-bearing grade (yttrium and zirconium additions) engineered for elevated-temperature service up to 300 degrees Celsius and for biomedical implant applications where controlled corrosion and biocompatibility are required. While WE43 sees less volume in Green Bay's industrial shops than AZ31B or AZ91D, its application in orthopedic hardware and high-temperature aerospace brackets puts it on the radar for suppliers pursuing diversified work outside the traditional heavy-equipment market.

Magnesium can be TIG welded using AZ61A or EZ33A filler rod, but the process demands clean base metal, shielding gas discipline (pure argon, no CO2), and preheating to 300-400 degrees Fahrenheit to prevent cracking in thicker sections. Green Bay's welding-fabrication shops servicing the construction and heavy-equipment OEM supply chain have the TIG capacity to handle magnesium assemblies, though operators require specific training to manage the fire risk from magnesium dust and shavings. Shops that have added magnesium to their material roster typically designate dedicated fixturing, grounding straps, and dry-sand fire extinguishers — overhead that qualified suppliers have already built into their rates. Post-processing options for Green Bay-produced magnesium parts include micro-arc oxidation (MAO) coatings for hard, wear-resistant surfaces, chemical conversion coating per MIL-M-3171 for corrosion protection, and powder coat over a chromate primer for color and outdoor durability. Dimensional inspection on magnesium requires the same CMM capability used for aluminum and steel work — tolerances tighter than +/-0.002 inch on magnesium are achievable on stable machines, though thermal expansion (coefficient of 26 micrometers per meter per degree C) must be accounted for in temperature-controlled inspection rooms.

Raw magnesium stock — billet, plate, and rod — is not stocked at the same density as aluminum in Wisconsin service centers, so lead time planning is critical. Most Green Bay shops source AZ31B plate and AZ91D casting alloy through Midwest metals distributors in Milwaukee, Chicago, or Minneapolis, with typical delivery windows of 5-10 business days for standard sizes. For die-cast blanks, regional foundries in the broader Great Lakes basin can supply rough castings for finish machining locally. ManufacturingBase connects buyers directly to verified Green Bay and northeast Wisconsin suppliers who have demonstrated magnesium handling capability, proper fire-safety infrastructure, and the inspection documentation that OEM customers require. When project timelines compress — as they do in seasonal construction equipment builds — having pre-vetted local sources cuts the qualification cycle from weeks to days. Buyers should specify alloy grade, temper designation, and required certifications (material test reports, Certificate of Conformance) in their RFQ to get accurate first-round quotes.