A working guide to choosing aluminum, stainless, copper, brass and steel for custom fabrication. Grade, temper, thickness and finish, matched to the bend radii and loads your part has to survive.
Full-hard temper or a tight bend radius across the grain. 5052-H32 bends; 6061-T6 often needs a larger radius or a relieved bend line. If the drawing asks for R0.5 on 2 mm 6061-T6, the press brake will tell you before we do.
304 stainless specified for a marine or wash-down enclosure. Chloride pitting starts at cut edges and weld heat-affected zones. 316L or 316 costs more per kilogram and saves the whole assembly. We flag this at DFM review, not after anodizing.
Aluminum housing bolted to a stainless bracket with no isolation. Add moisture and the aluminum becomes the anode. Plating the steel, using aluminum hardware, or a barrier washer breaks the circuit. Cheap at design, expensive at field failure.
Gauge numbers differ between ferrous and non-ferrous standards. 16 ga steel is 1.519 mm; 16 ga aluminum is 1.290 mm. A drawing that says 16 ga without a standard can shift your bend allowance and your bracket height by a few tenths.
Grade, temper and thickness decide what the brake, laser and welder can hold.
Aluminum is the default for enclosures, brackets and chassis because the strength-to-weight ratio is good and the material machines and welds cleanly. We stock 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075 and ADC12. The choice usually comes down to one question: will the part be bent after machining?
T6 temper gives yield strength near 276 MPa but cracks if you ask for a bend radius under roughly one material thickness. 5052-H32 is softer and takes tight radii without relief, which is why control panels and covers are usually cut from it. 7075 and 2024 are aerospace grades with high strength and poor weldability; they belong on machined ribs, not on welded frames.
Stainless carries at least 10.5% chromium by weight, and that passive layer is what holds up in food equipment, medical housings and outdoor hardware. We run 303, 304, 316, 316L, 420, 430, 431, 440C and 17-4PH. Grade 304 covers most general work. Move to 316L when chlorides or a welded joint in a corrosive environment are in the picture, because the molybdenum addition resists pitting at the heat-affected zone.
Copper and brass are specified for electrical and thermal reasons, not structural ones. C101 and C110 give electrical conductivity above 100% IACS and thermal conductivity near 390 W/m·K, which is why busbars and heat spreaders use them. Brass C36000 machines faster than any other common alloy and takes a bright finish. It is also noticeably heavier than aluminum, so weight budget matters.
Beryllium copper sits between the two: high strength plus good conductivity, used for spring contacts and RF shielding. It requires controlled handling because beryllium dust is a health hazard, so we machine it wet and contain the swarf.
Mild and alloy steels cover the heavy end of fabrication. We cut and form 1018, 1045, 4130, 4140, 4340, A36 and tool steel. A36 is the workhorse for weldments and structural frames. 4130 and 4140 come in when the part needs higher tensile strength or through-hardening after machining, common in automotive and industrial machinery links.
Gauge is a thickness shorthand that causes real problems. The ferrous gauge standard puts 16 ga at 1.519 mm and 20 ga at 0.912 mm. The non-ferrous standard puts 16 ga at 1.290 mm. Same number, different sheet. When a drawing gives gauge without naming the standard, bend allowance and finished height drift by a few tenths of a millimetre.
Our rule is simple: every drawing gets an explicit thickness in millimetres or inches, and the gauge equivalent if the customer wants it. Laser cutting holds ±0.005 mm on position, so the thickness you specify is the thickness that arrives in the bend deduction table.
Common grades we stock and the jobs they fit.
| Material | Typical grade | Use it when | Watch out for |
|---|---|---|---|
| Aluminum | 5052-H32 | Part will be bent after cutting | Lower strength than T6 |
| Aluminum | 6061-T6 | Structural bracket or machined plate | Bend radius under 1 t will crack |
| Stainless | 304 | General corrosion resistance, indoor | Pitting in chloride environments |
| Stainless | 316L | Marine, medical, welded corrosive joints | Higher cost, slightly lower strength |
| Copper | C110 | Busbars, heat spreaders, RF shields | Very soft, dents in handling |
| Brass | C36000 | Connectors, fittings, decorative parts | Heavier than aluminum |
| Steel | A36 | Weldments and structural frames | Rusts without coating |
| Steel | 4130 / 4140 | High-strength links and shafts | Needs heat treatment to reach spec |
Fiber laser cuts aluminum, stainless, copper, brass and steel sheet. Position tolerance ±0.005 mm. Copper and brass need higher power, which we account for in nesting and cut speed.
CNC press brakes with tooling for tight radii and long bends. Bend allowance calculated from the actual measured thickness, not the nominal gauge.
TIG and MIG for aluminum, stainless and steel. Spot welding and riveting for enclosures. Weld maps agreed before production so the heat-affected zone is planned, not patched.
127 high-precision CNC machines including 16 simultaneous 5-axis centers. Machined features, tapped holes and pockets on formed parts come off the same shop floor.
Anodizing, electroless nickel, zinc, silver and gold plating, powder coating, black oxide, bead blasting, brushing and laser marking. Finish is chosen with the alloy, not after it.
100% inspection before shipment: raw material check, in-process monitoring, final inspection. Reports on request. Tolerances verified against the drawing you supplied.
Practical limits for the materials on this page.
| Process | Typical range | Notes |
|---|---|---|
| Laser cutting | 0.5–20 mm | Thicker sections cut on request |
| Press brake forming | 0.5–12 mm | Radius depends on grade and temper |
| Max processing size | 4,000 mm | 4,000 × 400 × 150 mm travel |
| Tolerance | ±0.005 mm | Position, laser cut features |
| Surface finish | Ra 0.8–1.6 μm | Ra 0.2–0.8 μm on request |
| Volume | 1 to 10,000+ parts | No minimum order quantity |
Fifteen years making custom metal parts in Dongguan. The material knowledge is shop-floor experience, not a catalogue.
Send a drawing and we return a quotation with free DFM analysis within 12 hours. Material substitutions are flagged before you commit, not after cutting starts.
Once the drawing and material are confirmed, production can start within 24 hours. Parts ship in 3–5 days. Historical late-delivery probability is below 2%.
One prototype or a 10,000-part run, same process and same inspection. Material grade stays the same at both ends of the volume range.
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022. Medical and automotive material traceability available.
Files are stored securely and never shared. NDA available on request before you send the first drawing.
Lightweight structure with tight tolerances. 7075 and 2024 for machined ribs, 6061-T6 for brackets.
Battery enclosures, busbars and structural links. C110 copper for current paths, 4130 for high-strength links.
Housings and instrument frames in 316L or 304, finished for repeated cleaning and disinfection.
Chassis, shields and heat spreaders. Aluminum for weight, copper for thermal and RF paths.
5052-H32 is the safe default. It forms tight radii without cracking and welds well. Use 6061-T6 only if the part carries structural load and the bend radii are at least one material thickness.
If the design needs both a tight bend and high strength, split the part: a 6061-T6 machined frame with a 5052 formed cover. That is usually cheaper than fighting the T6 temper in the brake.
Start with the environment. Indoor, dry, no chlorides: 304 is fine and costs less. Coastal air, wash-down chemicals, saline contact, or any welded joint exposed to chloride: go to 316L.
The molybdenum in 316L slows pitting at the weld heat-affected zone, which is where 304 usually fails first. For medical housings that get repeatedly disinfected, 316L is the usual choice.
Only if you name the standard. Ferrous gauge and non-ferrous gauge give different millimetre values for the same number. 16 ga is 1.519 mm in steel and 1.290 mm in aluminum.
We ask every customer to put an explicit thickness in millimetres or inches on the drawing. If gauge matters for sourcing, add the equivalent in parentheses. That removes the ambiguity from the bend deduction.
When the part moves current or heat. C110 copper gives electrical conductivity above 100% IACS and thermal conductivity near 390 W/m·K, which aluminum does not match. Busbars, heat spreaders and RF shields belong in copper.
Brass C36000 is for connectors, fittings and visible hardware. It machines faster than any other common alloy and takes a bright finish. Both metals are heavier than aluminum, so check the weight budget before switching.
Yes, but we will confirm the intended standard before cutting. Many legacy drawings were made under a single house standard, so we ask once and record it against the part number.
If the drawing is ambiguous and the part is already in production elsewhere, we measure a sample and work backwards to the thickness that matches. That is faster than guessing and re-cutting.
Anodizing suits aluminum: clear, colour, hardcoat and conductive variants. Hardcoat anodize on 6061-T6 gives a wear surface for sliding parts. Stainless and steel take electroless nickel, zinc, black oxide or powder coating.
Copper and brass accept plating, silver and gold included, which is common on contacts. Laser marking needs a minimum character height of 1.5 mm to stay legible after finishing.
Yes. We stock titanium TA1, TA2 and TC4 (Ti-6Al-4V), Inconel, magnesium AZ31B and AZ91D alongside the common grades. There is no minimum order quantity, so a single prototype is workable.
Exotic grades may need a longer material lead time than the 3–5 day standard ship window. We tell you the material availability in the quotation rather than after the order is placed.
Every order goes through a raw material check against the mill certificate, then in-process monitoring, then final inspection. That is 100% inspection before shipment, not sampling.
Inspection reports are available on request. For automotive and medical programs we keep material traceability tied to the part number and the production lot.
Upload your files and we return a quotation with free DFM analysis within 12 hours, including grade and finish advice.
12-hour quote100% inspectionNo minimum orderNDA on request
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
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