RAYCHIN LIMITED

Inconel Flat Head Screws – Configurations & Standards

International Standards & Global Designations – Inconel Flat Head Screws

RAYCHIN LIMITED manufactures Inconel flat head screws from material conforming to the most widely used national and international specifications. All material is traceable to the mill.

Chemical Composition (Weight %) – Inconel Alloys for Flat Head Screws

Our Inconel flat head screws are produced from melts conforming to the following limits per ASTM/ASME/AMS.

Inconel 600 (UNS N06600 / 2.4816)

Inconel 625 (UNS N06625 / 2.4856)

Inconel 718 (UNS N07718 / 2.4668)

Metallurgical note: High nickel content (≥50%) provides exceptional resistance to chloride stress corrosion cracking. Chromium (14–23%) ensures oxidation resistance up to 1150°C. Molybdenum (in 625) and Nb+Ti (in 718) contribute to solid‑solution strengthening and precipitation hardening, giving these Inconel flat head screws their signature high‑temperature strength.

Complete Mechanical & Physical Properties – Inconel Flat Head Screws (MPa / ksi)

Inconel flat head screws are supplied in solution annealed (600, 625, 601) or age‑hardened (718, X‑750) condition per specification. Data represent typical minimum or range values based on ASTM, AMS, and industry standards. ksi values (kilopound per square inch) are provided alongside MPa.

Mechanical Properties – Minimum Requirements (room temperature) for Flat Head Screws

Physical Properties (typical) – Inconel Flat Head Screws

High‑Temperature Performance of Inconel Flat Head Screws

Inconel superalloys retain significant strength at elevated temperatures, making Inconel flat head screws ideal for gas turbines, furnace assemblies, and exhaust systems. Data below demonstrate the superiority of Inconel 718, 625, and 601 for high‑T applications. Strength values are shown in MPa and ksi.

Elevated Temperature Tensile – Inconel 718 (age hardened) for Flat Head Screws

High‑Temperature Limits & Oxidation Resistance – Flat Head Screws

At 650°C, Inconel 718 retains about 80% of its room‑temperature tensile strength, outperforming many other alloys. Inconel 625 and 601 provide outstanding resistance to oxidation and carburization at even higher temperatures, making them excellent choices for high‑temperature flat head screws.

Exceptional Corrosion Resistance of Inconel Flat Head Screws

The high nickel and chromium content imparts resistance to a wide range of corrosive media: chlorides, acids, and alkalis. Inconel 625 and Inconel 718 flat head screws are particularly resistant to pitting and crevice corrosion in seawater and sour environments.

• Chloride stress corrosion cracking (SCC): All Inconel grades (600, 625, 718) exhibit high resistance due to Ni >40% .
• Sulfuric & Hydrochloric acids: Inconel 625 shows exceptional performance in reducing acids (Mo addition).
• Sour service (H₂S): Inconel 625 & 718 qualified per NACE MR0175/ISO 15156 for oil & gas .
• Oxidation & carburization: Inconel 601 outperforms due to aluminum addition .
• Seawater: Inconel 625 resists pitting and crevice corrosion, used extensively in marine fasteners.

Manufacturing Standards – Inconel Flat Head Screws

All Inconel flat head screws are manufactured and tested to meet:

We offer surface finishes: passivation (ASTM A967), silver plating (AMS 2410 for anti‑seize), PTFE coating, and electropolish. Full traceability and destructive/non‑destructive testing available (UT, MPI, PMI).