Brass Machining and Fabrication in Burlington, NC: C360, C260, and Naval Brass

C360 free-machining brass is the undisputed choice for high-volume turned and milled brass components. With approximately 3 percent lead, C360 achieves a machinability rating of 100 — the benchmark against which all other metals are measured. Chips break short and cleanly, surface finish is excellent, and tool life is long compared to any other copper alloy. Burlington screw machine shops running C360 bar stock produce automotive fuel fittings, hydraulic adapters, and plumbing components with cycle times that make production economics compelling. The lead content in C360 does create restrictions: it is not acceptable in potable water plumbing under current NSF/ANSI 61 low-lead standards, and its use in automotive fuel systems serving markets with strict lead regulations requires engineering review. For industrial hydraulic and non-potable fluid applications, C360 remains the cost and productivity leader. C260 cartridge brass (70 percent copper, 30 percent zinc) is the forming alloy of the brass family. Absent the lead addition of C360, C260 draws, forms, and bends without cracking, making it standard for deep-drawn shells, formed brackets, and spring components where the part geometry is achieved by plastic deformation rather than material removal. Machinability of C260 is significantly lower than C360 — it rates around 30 on the standard scale — but its formability in the half-hard and hard tempers is excellent. Burlington fabricators with press and forming capability process C260 for battery connector clips, shield housings, and formed brackets in the automotive electrical space. Naval brass (C464) is a specific grade with approximately 60 percent copper, 39 percent zinc, and 0.75 to 1.0 percent tin. The tin addition inhibits dezincification in marine and brackish water environments that would attack standard yellow brass by selectively leaching zinc from the alloy. Naval brass is specified for marine hardware, seawater-cooled heat exchanger components, and any fitting exposed to salt spray or seawater immersion. Burlington shops can source and machine naval brass on request, though it is a specialty grade typically ordered to specific project requirements rather than stocked in standard bar sizes.

Burlington's CNC turning infrastructure, built up over decades of automotive supply chain work, is well-suited to the economics of high-volume brass components. Screw machines (both traditional multi-spindle and modern CNC variants) running C360 hex bar can produce simple fittings and connectors in cycle times of 8 to 20 seconds per part, generating production rates of 150 to 400 pieces per hour per machine. For blanket orders of 10,000 pieces or more annually, Burlington shops can amortize tooling and setup cost across the volume to produce very competitive per-piece prices. The key input to production economics is bar stock form. C360 is available in round bar (the most common for turned components), hexagonal bar (preferred for hex-body fittings and valve bodies where a flat-to-flat dimension drives the part design), and square bar for specific geometries. Burlington shops that stock hex bar in multiple across-flat sizes can eliminate a flattening operation and reduce material waste on hex-body fittings. Including bar form preference in your RFQ — or inviting the shop to propose the most cost-effective form — helps drive the most competitive quote. For customers running Just-In-Time delivery schedules to automotive assembly plants in the Piedmont Triad or Charlotte corridor, Burlington brass shops that operate with blanket orders and scheduled releases provide the delivery reliability that JIT requires. A supplier 45 minutes from an assembly plant can respond to a pull signal or expedite request same-day; a supplier in another region cannot. Local sourcing of high-volume brass components reduces the safety stock required to buffer against supply chain disruption.

Brass's copper-zinc composition accepts electroplating readily and provides an excellent substrate for tin, nickel, chrome, zinc, and precious metal deposits. The standard commercial practice for automotive fluid fittings is nickel underplate followed by a topcoat appropriate to the service environment: tin for solderability, chrome for wear and aesthetics, or zinc-nickel for salt spray resistance per ASTM B117 requirements of 240 to 500 hours. Burlington shops coordinate with regional plating houses in the Piedmont Triad to deliver plated brass components as a finished, ready-to-assemble part rather than raw machined brass that the buyer must arrange plating for separately. For potable water applications using lead-free brass formulations (such as C87600 silicon bronze or bismuth brass alternatives to C360), additional surface treatments may be specified to meet NSF 61 certification requirements. Buyers migrating from C360 to lead-free brass for water-contact applications should discuss tooling life implications with their Burlington shop, since lead-free brass alloys are significantly harder to machine than C360 and may require different tooling grades and feeds and speeds adjustments that affect cycle time and cost. Bare machined C360 brass oxidizes to a yellow-brown patina within days in ambient air and within hours in humid industrial environments. For parts that require a bright cosmetic appearance or maximum solderability at assembly, packaging in VCI film or anti-tarnish bags immediately after machining is standard practice. Burlington shops shipping brass connector components to automotive assembly customers include packaging specifications in their control plans to prevent tarnish-related quality escapes at receiving inspection.

Dezincification is a corrosion mechanism that selectively leaches zinc from copper-zinc alloys, leaving a porous, weak copper sponge in its place. It is most aggressive in low-velocity, slightly acidic or neutral water containing dissolved oxygen and chlorides — conditions common in hot water systems, marine environments, and industrial cooling water circuits. Standard C360 and C260 yellow brass are susceptible to dezincification; naval brass C464 and inhibited brasses (with small arsenic or phosphorus additions) resist it through alloying chemistry. For Burlington buyers specifying brass components in wet or chemically active service environments, dezincification resistance should be part of the alloy selection conversation. ASTM B858 provides a dezincification resistance test that can be specified for acceptance testing of fittings intended for water service. If your application involves aggressive cooling water, slightly acidic process streams, or outdoor weathering in humid coastal climates, confirm with your Burlington supplier that the specified alloy is appropriate and whether additional testing or inhibited alloy variants are warranted. Brass fittings for natural gas distribution lines are another application where alloy and zinc content matter. ASTM B124 forged brass fittings for gas service are typically made from specific alloy compositions qualified under relevant gas utility specifications. Burlington shops with gas fitting manufacturing experience maintain awareness of the applicable material and testing standards.