---
title: "Hastelloy"
description: "Hastelloy (trademark of Haynes International) is a family of nickel-molybdenum-chromium alloys with extreme corrosion resistance in chloride-bearing, acidic and reducing environments. The most common grades for sonic-horn service are Hastelloy C276 and Hastelloy C22."
canonical_url: "https://sylio.co/glossary/hastelloy"
last_updated: "2026-06-28T02:29:35.145Z"
---

**Hastelloy** (trademark of Haynes International) is a family of nickel-molybdenum-chromium alloys with extreme corrosion resistance in chloride-bearing, acidic and reducing environments. The most common grades for sonic-horn service are **Hastelloy C276** and **Hastelloy C22**.

## Where it earns its premium

[AISI 316 / 316L](/glossary/aisi-316-316l-stainless) handles the majority of industrial sonic-horn corrosion duty. [Inconel 625 / 718](/glossary/inconel-625-718) handles high-temperature service. Hastelloy is specified where neither suffices — typically:

- Severe chloride environments (some [WtE](/glossary/waste-to-energy) and chemical process duties)
- Wet acidic gas exposure
- Specific chemical-process applications

Hastelloy carries a substantial cost premium (10–15× over 316) and is reserved for cases where lesser materials demonstrably fail.

## Related terms

- [Inconel 625 / 718](/glossary/inconel-625-718)
- [AISI 316 / 316L stainless](/glossary/aisi-316-316l-stainless)