Magnesium Sourcing and Machining in Scranton, PA

Magnesium runs about 1.74 g/cm3, roughly two-thirds the density of aluminum and a quarter that of steel, and that weight advantage is the entire reason it lands on a Scranton bill of materials. The automotive Tier 2 and Tier 3 shops feeding the NEPA corridor use AZ91D die castings for transmission cases, brackets, and steering-column components where every gram pulled out improves fuel economy and handling. Heavy-equipment builders specify magnesium for portable enclosures, gearbox covers, and tooling fixtures that get carried, swung, or repositioned by hand all shift. The second driver is damping. Magnesium absorbs vibration better than aluminum, which is why it appears in housings around rotating equipment and in handheld defense optics and sighting hardware fabricated locally. When a part has to be both light and quiet, magnesium beats the alternatives, and Scranton shops that already run aluminum and zinc alloys can usually add it without retooling. The trade-off is cost and corrosion. Magnesium stock runs higher per pound than aluminum, and bare magnesium corrodes aggressively in salt and humidity, so nearly every Scranton job ships with a chromate conversion coat, anodize, or powder finish. Budget for that finishing step up front rather than discovering it at first-article inspection.

AZ31B is the wrought workhorse, supplied as sheet, plate, and extrusion with roughly 3 percent aluminum and 1 percent zinc. Scranton fabricators use it for formed and welded assemblies, brackets, and panels because it bends and welds far more predictably than the cast grades. If your part starts from sheet or bar and gets sheared, formed, or TIG welded, AZ31B is almost always the right call. AZ91D is the high-pressure die-casting standard, with about 9 percent aluminum for strength and tightly controlled iron, nickel, and copper to keep corrosion in check. This is the grade behind the bulk of automotive and consumer magnesium castings, and the local die shops that pour zinc and aluminum can hold AZ91D to net or near-net shape, minimizing the machining a Scranton CNC house has to do afterward. WE43 is the premium grade, alloyed with yttrium and rare earths to hold strength at elevated temperature, up to roughly 250 C. It commands aerospace-defense and specialized motorsport work where AZ91D would creep or soften. WE43 carries a real price premium and tighter sourcing, so confirm material certs and full traceability before committing; for defense end-use, that paperwork is non-negotiable.

Magnesium cuts beautifully. It has the highest machinability rating of any common structural metal, takes aggressive feeds and speeds, and produces low cutting forces and excellent surface finish. A Scranton shop that knows the material will run sharp, high-rake tooling, keep depth of cut high enough to make chips rather than dust, and pull parts off the machine looking nearly polished. The hazard is fire. Fine magnesium chips and dust ignite, and once burning, magnesium cannot be put out with water or standard CO2 or ABC extinguishers, which make it worse. Reputable Scranton shops machining magnesium run dedicated Class D extinguishing media on hand, keep chip volume controlled, segregate magnesium swarf from steel and aluminum scrap, and often run dry or with mineral oil rather than water-based coolant. Ask any prospective vendor directly how they handle chips and what fire suppression they keep at the machine. This is also why you want a shop with magnesium experience rather than a low bid from someone treating it like aluminum. The cutting is easy; the housekeeping and risk management are what separate a clean job from an incident.