Magnesium Machining & Suppliers in San Diego, CA

The choice depends on form and performance needs. AZ31B is the common wrought alloy for sheet and extrusion, used in formed and machined structural components, valued for reasonable strength and good workability. AZ91 is a widely used cast-and-machined alloy for housings and structural castings. For higher performance, ZE41 and EZ33 offer good casting characteristics and elevated-temperature properties, while WE43 stands out for aerospace because it performs well at elevated temperature and, importantly, is classified as non-flammable in its finished solid form, which matters for flight-safety considerations. For San Diego's weight-critical UAV and aerospace components, the selection comes down to whether the part is wrought or cast, the operating temperature, and any flammability requirement on the finished part. Specify the alloy and temper or casting condition explicitly, and reference the governing AMS or ASTM spec. Because magnesium alloys differ substantially in properties and machining behavior, and because specialty alloys like WE43 can carry longer material lead times, confirm both the alloy choice and its availability with your shop early in the program.

Yes, magnesium is machined safely every day, but only by shops with the right procedures, which is why the qualified supplier pool is narrower than for aluminum. The risk comes from finely divided magnesium — chips, fines, and especially grinding dust — which is combustible and produces fires that are hard to extinguish (water and standard extinguishers can make a magnesium fire worse). Shops that machine magnesium properly manage it through several practices: keeping tooling sharp and using parameters that produce larger chips rather than fine dust, often machining dry or with mineral oil rather than water-based coolant, controlling and promptly removing swarf, keeping fines out of accumulation points, and having appropriate Class D fire-suppression media on hand. When qualifying a San Diego shop, ask directly how often they machine magnesium, what their coolant and chip-handling approach is, and how they manage swarf and fire suppression. A shop with genuine magnesium experience answers confidently and has documented procedures; a shop with no magnesium history should not be running your parts. This is a capability to verify in conversation and ideally with a floor visit, not just a website claim.

Magnesium is chemically reactive and corrodes readily, and San Diego's humid, salt-influenced coastal air makes corrosion protection essentially mandatory rather than optional. Two issues need addressing. First, surface protection: magnesium parts typically receive a conversion coating (chromate-type treatments historically covered by specifications like MIL-DTL-3171) or an anodize-type protective process, frequently followed by a primer and paint system for full environmental protection. The finishing should be specified on the print with the applicable spec, and the process certificates should travel with the parts. Second, galvanic corrosion: magnesium is very anodic, so wherever it contacts a dissimilar metal — aluminum, steel, or fasteners of another alloy — the galvanic couple accelerates corrosion of the magnesium. The design must isolate these joints, using compatible fasteners, insulating washers or coatings, or sealants to break the galvanic path. A San Diego shop experienced in magnesium will help specify both the surface treatment and the galvanic isolation correctly. Treat any unprotected magnesium part as one that will corrode quickly in service; the finishing and isolation are part of making the weight advantage durable, not an afterthought.

The pool is smaller for two related reasons: the fire-safety requirements mean only properly equipped shops machine magnesium, and the demand is specialized and lower-volume than common metals, so fewer shops invest in the capability. This changes your sourcing approach in several ways. Because you're choosing from a narrower set, you select more on demonstrated capability and safety than on competitive price-shopping across many vendors. Local San Diego sourcing becomes more attractive, since close oversight of a specialized, safety-sensitive process is valuable and since shipping flammable magnesium swarf and finished parts carries its own logistics considerations. You should also confirm raw-material availability early, because magnesium in your specific alloy and form — particularly specialty alloys like WE43 — isn't stocked as broadly as aluminum and can carry longer lead times. The practical strategy is to identify the small set of San Diego shops with proven magnesium experience, qualify them thoroughly on fire safety, finishing, and corrosion protection, and build an ongoing relationship rather than treating each magnesium part as a commodity buy. For weight-critical UAV and aerospace programs, that supplier relationship is worth protecting.