RAYCHIN LIMITED

Titanium Lock Nuts – Complete Product Range

Critical Applications of Titanium Lock Nuts

International Standards & Global Designations – Titanium Lock Nut Materials

RAYCHIN LIMITED manufactures Titanium lock nuts from material conforming to the most widely used national and international specifications. All material is traceable to the mill.

Chemical Composition (Weight %) – Titanium Alloys for Lock Nuts

Our Titanium lock nuts are produced from material conforming to the limits of applicable ASTM, AMS, and ISO standards. High‑purity grades available for medical and semiconductor applications.

Commercially Pure Titanium (Grades 1-4) – ASTM B348 / F67

Titanium Alloys – ASTM B348 / F136

Metallurgical note: Titanium is an allotropic element with a hexagonal close-packed (α) structure at room temperature, transforming to body-centered cubic (β) at 882°C. CP grades are α-phase, while alloying with aluminum stabilizes α-phase, and vanadium/molybdenum stabilize β-phase. Ti-6Al-4V is an α+β alloy combining high strength with good ductility. The natural oxide layer (TiO₂) is 2-5 nm thick, self‑healing, and responsible for titanium's exceptional corrosion resistance. Titanium is non‑magnetic with magnetic permeability <1.00005.

Complete Mechanical & Physical Properties – Titanium Alloys for Lock Nuts (MPa / ksi)

Titanium lock nuts are supplied in appropriate conditions (annealed for CP grades, solution treated and aged for Grade 5) per ASTM B348, ASTM F136, and customer specifications. Data represent typical values based on industry standards.

Commercially Pure Titanium – Mechanical Properties (minimum values)

Titanium Alloys – Mechanical Properties (minimum values)

High‑Temperature Mechanical Properties – Ti-6Al-4V (typical values)

Note: Prolonged exposure above 300°C may cause oxidation; protective coatings recommended above 500°C. All-metal lock nuts retain locking capability up to 400°C. Nylon insert lock nuts limited to 120°C.

Physical Properties – Titanium

High‑Temperature Performance of Titanium Lock Nuts

Titanium alloys retain significant strength at elevated temperatures up to 500°C, making them suitable for aerospace and automotive applications. Ti-6Al-4V maintains useful mechanical properties up to 315°C (600°F) for extended service, and up to 500°C (932°F) for short-term exposure. The alloy exhibits excellent creep resistance at moderate temperatures. For titanium lock nuts, the operating temperature is also limited by the locking element:

• Nylon Insert Lock Nuts: Operating range -50°C to +120°C. Suitable for general engineering, automotive, and aerospace interior applications.
• All-Metal Lock Nuts: Operating range -250°C to +400°C (cryogenic to elevated). Suitable for aerospace engines, exhaust systems, and high-temperature assemblies.

Titanium becomes increasingly reactive with oxygen above 500°C, forming an oxygen-enriched brittle α-case layer. For applications above 500°C, protective coatings (such as TiAlN) or high-temperature alloys (Ti-6242, Ti-1100) are recommended. Titanium's melting point (1660°C) is higher than steel, but oxidation limits practical use in air.

Elevated Temperature Capabilities

Note: Titanium alloys are susceptible to "alpha case" formation above 500°C in air, which embrittles the surface.

Exceptional Corrosion Resistance of Titanium Lock Nuts

Titanium is renowned for its outstanding corrosion resistance in a wide range of environments, often exceeding that of stainless steels and nickel alloys. The protective TiO₂ oxide film (2-5 nm thick) is stable in oxidizing media and rapidly self‑heals if damaged. Titanium is virtually immune to pitting, crevice corrosion, and stress corrosion cracking in chloride environments up to 200°C.

• Seawater / Marine: Titanium is completely resistant to seawater up to 120°C. Corrosion rate <0.01 mm/year in flowing seawater, with no measurable attack after decades of immersion. Immune to crevice corrosion in ambient seawater.
• Chlorides: Excellent resistance to chlorides, hypochlorites, and chlorine dioxide. Used in chlorine bleach plants and seawater desalination.
• Nitric Acid: Outstanding resistance up to boiling temperatures at all concentrations. Corrosion rate <0.1 mm/year.
• Acetic Acid: Excellent resistance at all concentrations and temperatures up to boiling.
• Sulfuric Acid: CP titanium resistant up to 5% at boiling, 10% at ambient. Grade 7 (Pd) extends resistance to 40% at boiling.
• Hydrochloric Acid: CP titanium resistant up to 3% at boiling, 8% at ambient. Grade 7 extends to 20% at ambient, 7% at boiling.
• Phosphoric Acid: CP titanium resistant up to 20% at ambient. Grade 7 extends to 40% at ambient, 10% at boiling.
• Organic Acids: Completely resistant to all organic acids, including formic, citric, and tartaric acids.
• Alkalis: Resistant to dilute alkalis at ambient. Attacked by concentrated hot alkalis.
• Halogens: Resistant to wet chlorine gas and chlorine solutions. Not recommended for dry chlorine above 200°C.
• Hydrofluoric Acid: Rapidly attacked by HF and fluoride-containing media – not recommended.
• Galvanic Corrosion: Titanium is cathodic to most metals; can accelerate corrosion of active metals (steel, aluminum) in contact. Isolation or coating recommended.
• Hydrogen Embrittlement: Titanium can absorb hydrogen in certain conditions (cathodic charging, acid pickling). Grades with Pd or Ru reduce hydrogen pickup.

Manufacturing Standards – Titanium Lock Nuts

All Titanium lock nuts are manufactured and tested to meet the following standards:

We offer surface finishes: plain (as‑machined), passivated, anodized. Titanium lock nuts can be supplied with certified material traceability, dimensional inspection reports, and mechanical test certificates. Our manufacturing processes include CNC tapping and precision thread forming. We specialize in custom configurations including non‑standard thread forms, special locking elements, and proprietary dimensions. Cleanroom packaging available for medical and semiconductor applications. All lock nuts supplied with EN 10204 Type 3.1 or 3.2 certification. ISO 9001:2015 and AS9100D certified quality management system.