RAYCHIN LIMITED

Inconel Screws – Complete Range of Head Styles & Drive Options

Critical Applications of Inconel Screws

International Standards & Global Designations – Inconel Screws

RAYCHIN LIMITED manufactures Inconel 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 Screws

Our Inconel 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/X-750) contribute to solid‑solution strengthening and precipitation hardening. Inconel 718's precipitation-hardened condition provides yield strengths exceeding 1035 MPa (150 ksi), ideal for high-stress screw applications.

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

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

Mechanical Properties – Typical Values (room temperature) for Inconel Screws

Physical Properties (typical) – Inconel Screws

High‑Temperature Performance of Inconel Screws

Inconel superalloys retain significant strength at elevated temperatures, making Inconel screws ideal for gas turbines, furnace fixtures, and exhaust systems. Data below demonstrate the superiority of Inconel 718, 625, and 601 for high‑T applications.

Elevated Temperature Strength – Comparison by Grade

At 650°C, Inconel 718 retains about 80% of its room‑temperature tensile strength and maintains a classification of 1275 MPa, 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 screws.

High‑Temperature Limits & Oxidation Resistance

Exceptional Corrosion Resistance of Inconel 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 screws are particularly resistant to pitting and crevice corrosion in seawater and sour environments.

• Chloride stress corrosion cracking (SCC): All Inconel grades exhibit high resistance due to Ni >40%; immune to chloride-ion SCC. Inconel 600 shows excellent resistance to ammonia corrosion.
• 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 forming protective Al₂O₃ scale.
• Seawater: Inconel 625 resists pitting and crevice corrosion, used extensively in marine fasteners. In mild environments such as atmosphere, sea water, and alkaline media, there is almost no attack.
• High-purity water & alkalis: Inconel 600 offers excellent corrosion resistance in nuclear applications.
• Dry chlorine & hydrogen chloride: Inconel 600 resists attack up to 650°C.

Manufacturing Standards – Inconel Screws

All Inconel screws are manufactured and tested to meet:

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