Product Description

Overview

Hastelloy C276 Gaskets are corrosion-resistant flat washers made from a nickel-molybdenum-chromium high-performance alloy processed with high precision. It can replace ordinary stainless steel in harsh conditions in petrochemical, environmental protection facilities, marine factories, and the medical industry, ensuring sealed connections and fastening of key components. Of course, our company can also customize other nickel alloy products. If interested, please feel free to contact us by email.

Advantages

Extreme corrosion resistance: resistant to strong acid corrosion, localized corrosion, and dual resistance to oxidation/reduction gases.
High-temperature resistance: Maintains good mechanical properties and structural stability even in medium to high temperature environments.
High strength and toughness: Compared to stainless steels like 316L, C276 has higher tensile strength (about 860 MPa) and good ductility, allowing it to withstand high bolt preload and is less prone to deformation or breakage.
Good formability: Despite its high strength, it still has excellent cold and hot forming properties, making it easy to stamp into flat washers, spring washers, square washers, and various standard or non-standard shapes.

Dimension

Grade	Hastelloy C276
Diameter	DN15-DN600/M3-M36
Thickness	1-3mm
Density	8.89 g/cm³
Tensile strength	830-1100 MPa
Hardness	HV 200-260
MOQ	10PCS
Standard	ASTM B564
Delivery time	25-30days
Certification	ISO 9001

Application

1. Chlor-alkali / Fine Pharmaceutical Chemicals

Hastelloy C276 gaskets are suitable for wet chlorine gas, mixed acids, and halogenation reaction media. Used for flange sealing in reactors, chlorine pipelines, and distillation equipment, they solve the problem of rapid corrosion and perforation associated with standard stainless steel.

2. Oil & Gas Extraction

To withstand hydrogen sulfide, carbon dioxide, and high-chloride formation brines, Alloy C276 washers are used at wellheads and in high-pressure gathering and transmission pipelines, preventing leaks caused by sulfide stress corrosion cracking.

3. Pulp and Paper Industry

Hastelloy C276 washers are compatible with chlorine dioxide and acidic bleaching/cooking liquors. Designed for flanges on bleaching towers and pulp washers, they eliminate leakage caused by crevice corrosion from chloride ions.

4. Seawater Desalination & Marine Engineering

Suitable for long-term exposure to high-temperature, high-chloride seawater and marine salt spray; used in high-pressure desalination pipelines and offshore platform cooling equipment, offering resistance to seawater pitting and salt spray corrosion.

5. Hydrometallurgy / Rare Earth Extraction

Hastelloy C276 gaskets are used in nickel, cobalt, and rare earth leaching and acid-purification equipment. They withstand hydrochloric and sulfuric acid-mixed slurries, ensuring long-term, rust-free sealing stability for extraction tanks and evaporators.

6. Nuclear Power & Hazardous Waste Incineration

Suitable for radioactive, chlorine-containing waste liquids and high-temperature acidic incineration flue gases; corrosion-resistant and stable at high temperatures, meeting safety requirements for sealing highly corrosive media.

7. Electroplating & Specialized High-Temperature Equipment

Used with electroplating pickling tanks and graphite heat exchangers; capable of withstanding mixed-acid conditions ranging from cryogenic temperatures (-196°C) to high temperatures (400°C) without failure during thermal cycling.

Processing

Raw material acceptance→ cutting and forming→ deburring→ solution annealing→ surface passivation→ dimensional flaw detection→ packaging

(1) Use C276 cold-rolled thin sheet/coil material that meets ASTM standards, verify material listing, and re-examine the components spectra, check the board surface for cracks, peeling, or oxidation defects, and cut the standard slab blank as needed.

(2) The entire thin plate is fed into a dedicated high-speed punch press mold, where the inner and outer circles are punched in one go, resulting in high efficiency and good dimensional consistency; Only suitable for standard metric / American standard bolt flat washers.

(3) Remove sharp edges through sanding, drum polishing, or CNC chamfering to avoid scratching the flange during assembly and causing gap corrosion points.

(4) Solution annealing: after holding at 1120–1150°C, rapid water cooling eliminates work hardening and restores original intergranular corrosion resistance.

(5) Wash the high-temperature oxide scale with mixed acids, then apply passivation treatment to form a dense protective film, enhancing corrosion resistance under wet chlorine and mixed acid conditions, while also removing surface free iron impurities.

(6) Comprehensive quality inspection, such as dimensional inspection, hardness testing, non-destructive testing, and chemical composition verification.