Hastelloy C-22 Machining Services

Hastelloy C-22 (UNS N06022) represents one of the most corrosion-resistant nickel-chromium-molybdenum-tungsten alloys available for chemical processing applications. With 40 years of combined experience machining high-performance nickel alloys, GQ Machining understands the unique challenges this material presents—from work hardening during cutting to maintaining dimensional stability as thermal expansion affects tolerance control. Our 5-axis CNC milling capabilities and precision grinding processes achieve ±0.0001″ tolerances with mirror surface finishes in this demanding alloy.

While both C-22 and C-276 are Hastelloy alloys, C-22 delivers superior resistance to oxidizing environments, pitting, and crevice corrosion—particularly in applications involving chlorine exposure. This makes C-22 the preferred specification for pharmaceutical manufacturing equipment, chemical processing vessels, and pollution control systems where aggressive oxidizers are present. The material’s 22% chromium content (compared to 15.5% in C-276) provides this enhanced protection, though it commands a higher material cost offset by extended service life in harsh chemical environments.

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Hastelloy C-22 Machining Capabilities

Machining Hastelloy C-22 requires specialized knowledge of nickel alloy behavior. The material work hardens rapidly under cutting forces, creating localized hardness that can destroy tooling if feed rates and speeds aren’t controlled precisely. Our machinists have decades of hands-on experience managing these challenges:

Our Haas 5-axis mills with 12,000 RPM high-speed spindles maintain consistent chip evacuation, preventing work hardening from rubbing rather than cutting. For Hastelloy C-22, we use carbide tooling with controlled depth of cut and feed rates that keep cutting forces in the plastic deformation range below work hardening thresholds. Surface speeds typically run 40-80 SFM with chip loads adjusted for part geometry—conservative by steel standards but necessary for nickel alloy machinability.

Tight tolerance work in Hastelloy C-22 requires accounting for the material’s thermal expansion coefficient (6.3 × 10⁻⁶ in/in/°F). Parts must stabilize to ambient temperature between roughing and finishing passes. Our climate-controlled shop maintains consistent conditions, and we incorporate thermal rest periods into production schedules. Wire EDM processes achieve ±0.0001″ tolerances on features where thermal expansion would compromise conventional machining accuracy.

Surface finish quality on Hastelloy C-22 chemical processing components directly affects corrosion resistance—surface irregularities create crevice sites for localized attack. We achieve mirror finishes (8-16 Ra) through controlled grinding and polishing sequences, removing tool marks that could compromise the material’s corrosion resistance. For sanitary pharmaceutical applications, we meet FDA surface finish requirements without scratches or contamination that could harbor bacteria.

Hastelloy C-22 Technical Specifications & Composition

Material Designation: UNS N06022 (Alloy C-22)

Composition: 56% Nickel, 22% Chromium, 13% Molybdenum, 3% Tungsten, 3% Iron, balance Cobalt/Manganese

Density: 0.316 lb/in³

Melting Point: 2,500°F (1,371°C)

Thermal Expansion: 6.3 × 10⁻⁶ in/in/°F (20-200°F)

Machinability Rating: Slightly better than C-276 but still challenging—rapid work hardening requires positive rake tooling and consistent chip removal

When to Specify Hastelloy C-22 Over C-276

Engineers specify Hastelloy C-22 when corrosion conditions exceed C-276’s capabilities. The higher chromium content in C-22 provides superior resistance to oxidizing environments—chlorine, ferric chloride, cupric chloride, and hypochlorite solutions that would attack C-276. For chemical processing equipment handling these oxidizers, C-22’s material cost premium is offset by extended equipment life and reduced maintenance shutdowns.

Pitting and crevice corrosion resistance also favor C-22 in applications with stagnant or low-velocity fluids where localized attack initiates. Pharmaceutical manufacturing equipment, where cleaning validation requires extended exposure to strong oxidizing sanitizers, benefits from C-22’s resistance to pitting during CIP (clean-in-place) cycles. Pollution control equipment scrubbing chlorine or handling acidic condensates similarly requires C-22’s performance.

From a machining perspective, C-22 is marginally easier to machine than C-276—the tungsten addition improves machinability slightly. Both alloys work harden aggressively and require similar cutting parameters, but tooling life may extend 10-15% with C-22. For our shop, this difference is minor; material selection should be driven by corrosion requirements, not machining considerations.

Applications & Industries for Hastelloy C-22 Components

Food Processing Equipment (Specialty)

While 316L stainless steel handles most food applications, specialty processes involving aggressive sanitizers or unusual pH conditions may require C-22. Mixing equipment for acidified foods or vessels requiring frequent high-temperature oxidizing sanitization.

Chemical Processing Equipment

Reactor vessels, heat exchangers, impellers, and mixer blades for chemical processing handling oxidizing acids, chlorine compounds, or mixed acid streams. C-22’s broad corrosion resistance eliminates the need for material changes during process variations.

Pollution Control Systems

Flue gas desulfurization equipment, scrubber components, and ducting handling acidic condensates with oxidizing species. C-22 withstands both the acidic environment and oxidizing conditions present in exhaust gas cleaning.

Pharmaceutical Manufacturing

Process equipment requiring sanitary finishes and repeated exposure to oxidizing sanitizers. Mixing vessels, transfer pumps, and filter housings where FDA compliance and corrosion resistance both matter.

Why Choose GQ Machining for Hastelloy C-22 Parts

40 Years Hastelloy Experience

Our combined team experience with Hastelloy alloys goes back nearly four decades. We understand how C-22 behaves during machining—not from reading data sheets but from thousands of hours running nickel alloys through our equipment. When an engineer specifies C-22 instead of C-276, we understand the corrosion engineering reasoning behind that decision and the finish quality requirements that typically accompany it.

Chemical Processing Industry Knowledge

We’ve manufactured mixer blades, impellers, and reactor components for chemical processing equipment where C-22’s corrosion resistance is necessary. This industry familiarity means we anticipate finish quality requirements, understand where tolerance stackup matters for assembly, and recognize when certain features need EDM rather than conventional machining to maintain dimensional control.

Small Shop Quality Control

Hastelloy C-22’s material cost makes scrap expensive. As a smaller shop, we can give each part the attention required to get it right the first time. Your chemical processing components won’t be rushed through to make room for higher-volume orders. We maintain the slower feed rates and careful tool monitoring that nickel alloys require for proper machining.

Precision Capabilities

Our 5-axis CNC milling centers handle complex geometries in C-22—mixing blade profiles, impeller curves, and reactor vessel internals requiring multi-axis machining. Wire EDM achieves ±0.0001″ tolerances on features where thermal expansion complicates conventional machining. Surface grinding produces the mirror finishes that pharmaceutical and sanitary applications demand.

Related Hastelloy Machining Services

GQ Machining provides comprehensive exotic metals machining services beyond Hastelloy C-22. Our experience with difficult nickel alloys extends to related materials specified for chemical processing and high-temperature applications.

Hastelloy C-276 Machining Services

Broader chemical resistance for reducing environments; the most common Hastelloy specification for general corrosive service

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Inconel 718 Machining Services

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Request a Quote for Hastelloy C-22 Machining

GQ Machining manufactures custom CNC machined components from Hastelloy C-22 for chemical processing, pharmaceutical manufacturing, and pollution control applications. We serve equipment manufacturers throughout New York, New Jersey, and Connecticut. Provide us with your engineering drawings or component specifications for an accurate quote. We respond to all inquiries within 24 business hours.

Call (845) 866-5869

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