Tantalum Lock Nuts
Tantalum Lock Nuts are also extremely stable at high temperatures, since tantalum has a melting point around 3000°C. High temperature applications require vaccum or inert gas since tantalum may embrittle when used in oxygen rich environments above 250°C. Tantalum Lock Nuts are also one of the most bio-compatible metals available and is also radio-opaque due to its high density (16.68 g/cm3).
All tantalum Lock Nuts are available in commercially pure tantalum and tantalum 2.5% tungsten (Ta-2.5%W).
RAYCHIN SPECIALTY METALS FASTENERS: BOLTS, NUTS, SCREWS, WASHERS, STUDS, THREADED RODS, U-BOLT, J-BOLTS
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Immune to numerous acids and chemicals
Better corrosion resistance than nickel alloys, titanium or zirconium
High strength and stiffness in vacuum and inert gas up to 2000°C (3600°F)
Can become brittle when used in oxygen above 300°C
High purity and biocompatibilty
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Tantalum Lock Nuts · Self-Locking Nuts · Prevailing Torque Nuts · Inch & Metric · UNS R05200 / R05252Tantalum Lock Nuts: Extreme Corrosion Resistant Self-Locking Nuts for Chemical, Medical & Aerospace Applications
RAYCHIN LIMITED is a leading manufacturer of Tantalum Lock Nuts – precision self-locking nuts produced from refractory tantalum metal, delivering unmatched corrosion resistance, biocompatibility, and reliable performance in the most demanding chemical processing, medical, and semiconductor applications. Lock nuts incorporate integrated locking mechanisms that resist loosening under vibration and thermal cycling, with the locking feature achieved through all-metal flexloc designs or polymer insert elements. Tantalum is a refractory metal with a melting point of 2996°C (5425°F) and corrosion resistance similar to glass – immune to virtually all acids and chemicals except hydrofluoric acid and hot concentrated alkalis. The material forms a stable, self-healing oxide layer (Ta₂O₅) that provides exceptional protection in aggressive environments. Our product line includes commercially pure tantalum lock nuts and tantalum 2.5% tungsten alloy lock nuts – all manufactured to the highest precision standards. Tantalum grades conform to UNS R05200 (electron-beam or vacuum-arc melted unalloyed tantalum) and UNS R05252 (tantalum 2.5% tungsten alloy) per ASTM B708 and ASTM B521 specifications. Our portfolio includes all standard and custom configurations manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS standards, including ISO 7040, ISO 7042, DIN 985, DIN 980, and ASME B18.16.3. Whether you require tantalum lock nuts for chemical reactor linings, medical implants, or high-temperature vacuum furnaces, RAYCHIN delivers precision, quality, and full traceability. All mechanical properties are presented in MPa and ksi (kilopound per square inch).
Tantalum Lock Nuts – Comprehensive Product Range
All-Metal Flexloc Lock Nuts
Tantalum flexloc lock nuts feature an all-metal design with a segmented collar that creates six "locking fingers" acting as a spring. This prevailing torque mechanism provides reliable locking action at high temperatures where polymer inserts cannot be used. The one-piece construction distributes load evenly and meets military standards for 15 cycles of prevailing torque. Ideal for high-temperature applications in vacuum furnaces and aerospace assemblies up to 2000°C in inert atmospheres. Available in hexagonal and 12-point configurations.
Polymer Insert Lock Nuts
Tantalum polymer insert lock nuts incorporate a non-metallic insert (typically nylon or high-performance polymers like Vespel or PVDF) that deforms elastically over the mating threads, providing excellent locking action while eliminating galling and cold-welding common with exotic alloys. Suitable for applications below 350°F (175°C) with polymer insert, or higher temperatures with advanced polymer options. Available in hex and 12-point configurations. Excellent reusability – can reliably be reused 15 times while maintaining locking torque.
Commercially Pure Tantalum (R05200)
Commercially pure tantalum lock nuts are produced from UNS R05200 material, meeting ASTM B708 and ASTM B521 specifications. Purity exceeds 99.95% tantalum with minimal interstitial elements. This grade offers exceptional corrosion resistance – virtually immune to attack by most acids including hydrochloric, nitric, sulfuric (up to 175°C), and aqua regia. Used in chemical processing equipment, pharmaceutical reactors, and medical implants requiring maximum biocompatibility.
Tantalum 2.5% Tungsten (R05252)
Tantalum 2.5% tungsten alloy lock nuts provide enhanced strength while maintaining tantalum's exceptional corrosion resistance. The addition of tungsten (2.5%) increases tensile and yield strength while maintaining excellent corrosion resistance. Conforms to UNS R05252, ASTM B708, and ASTM B521 specifications. Preferred for chemical processing and aerospace applications requiring superior strength in highly corrosive environments. The alloy maintains excellent corrosion resistance while offering improved mechanical properties.
Aerospace & Medical Standards
Our tantalum lock nuts meet applicable sections of NAS1291 (self-locking nuts), MS21042, NASM 1312-13, and AN standard equivalents. Full compliance with ASTM B708 (tantalum plate, sheet, strip), ASTM B521 (tantalum tube), and ASTM F560 (tantalum for surgical implants). All-metal flexloc designs certified for 15 cycles of prevailing torque – meeting military standards. Cleanroom packaging available for medical and semiconductor applications.
Custom & Non-Standard Lock Nuts
Need special thread forms, non-standard drive configurations, custom locking features, or unique plating requirements? RAYCHIN engineers design and produce custom tantalum lock nuts to your exact specifications – any condition (annealed, stress-relieved), with full material traceability. Available in all-metal flexloc, elliptical, stover, and polymer insert styles. Prototype to production volumes supported. Cleanroom wash and packaging available for medical and semiconductor applications.
Critical Applications of Tantalum Lock Nuts
Chemical Processing
Tantalum lock nuts are extensively used in chemical processing equipment including reactor linings, heat exchangers, distillation columns, and piping systems handling corrosive media. Tantalum exhibits virtually zero corrosion rate in most acids including hydrochloric, nitric, sulfuric (up to 175°C), phosphoric, and organic acids. The self-locking feature prevents loosening under thermal cycling and vibration in aggressive environments. Used in pharmaceutical manufacturing, fine chemical production, and specialty chemical processing where material purity must be maintained.
Medical & Implantable Devices
Tantalum lock nuts are qualified for medical implant applications due to tantalum's exceptional biocompatibility, corrosion resistance in body fluids, and radio-opacity. Tantalum is used for orthopedic implants, surgical instruments, and dental devices where secure locking is essential. The material is non-toxic and does not elicit adverse tissue reactions, making it ideal for long-term implantation. All-metal flexloc designs eliminate concerns about polymer degradation in body fluids. Meets ASTM F560 requirements for surgical implant applications.
Semiconductor Manufacturing
Tantalum lock nuts in semiconductor processing equipment including wafer handling systems, CVD reactors, and etch chambers. Tantalum's resistance to halogenated gases and plasma environments, combined with high purity (low interstitial elements), prevents contamination of sensitive semiconductor materials. The self-locking feature ensures reliable fastening in high-vibration environments. Used in chamber hardware, gas distribution systems, and wafer fixturing where corrosion resistance and purity are critical.
Aerospace & Defense
Tantalum lock nuts in aerospace applications including rocket engine components, high-temperature fasteners, and radiation shielding. Tantalum maintains useful mechanical properties in vacuum and inert gas up to 2000°C (3632°F), making it suitable for extreme temperature applications. All-metal flexloc designs provide reliable locking at temperatures where polymer inserts would fail. Used in propulsion systems, nozzle assemblies, and heat shields where high melting point and oxidation resistance (in non-oxidizing environments) are essential.
Pharmaceutical & Bioprocessing
Tantalum lock nuts in pharmaceutical manufacturing equipment including bioreactors, fermenters, and purification systems. Tantalum's corrosion resistance ensures no metal contamination of sensitive pharmaceutical products. The self-locking feature prevents loosening under vibration in agitated vessels. All-metal designs eliminate concerns about polymer degradation in sterilization cycles. Used in vessel internals, agitator assemblies, and sampling ports where corrosion resistance and secure fastening are critical.
High-Temperature Vacuum Furnaces
Tantalum lock nuts in vacuum furnace hot zones, heating elements, and heat shields. Tantalum maintains strength at elevated temperatures in vacuum or inert gas atmospheres, with recrystallization temperature above 1200°C. All-metal flexloc designs provide reliable locking at extreme temperatures up to 2000°C in non-oxidizing environments. Used in sintering furnaces, heat treating equipment, and crystal growing furnaces requiring refractory metal fasteners that maintain integrity at extreme temperatures.
International Standards & Global Designations – Tantalum Lock Nuts
RAYCHIN LIMITED manufactures tantalum lock nuts from electron-beam melted or vacuum-arc melted material conforming to the most widely used national and international specifications. All material is traceable to the mill.
Chemical Composition (Weight %) – Tantalum Grades
Our tantalum lock nuts are produced from electron-beam melted (EB) or vacuum-arc remelted (VAR) material conforming to the limits of applicable ASTM specifications.
Commercially Pure Tantalum – UNS R05200
Tantalum 2.5% Tungsten – UNS R05252
Metallurgical note: Tantalum is a refractory metal with a body-centered cubic (BCC) crystal structure. It exhibits exceptional corrosion resistance due to the formation of a stable, adherent oxide layer (Ta₂O₅) that protects the base metal from chemical attack. This oxide layer is self-healing in oxidizing environments and provides immunity to virtually all acids and chemicals except hydrofluoric acid, hot concentrated alkalis, and fuming sulfuric acid (oleum). Tantalum's high melting point (2996°C) makes it suitable for high-temperature applications in vacuum or inert atmospheres, though it may embrittle when exposed to oxygen above 300°C. The addition of 2.5% tungsten provides solid solution strengthening, increasing tensile and yield strength while maintaining excellent corrosion resistance. Tantalum is fully biocompatible, non-toxic, and radio-opaque, making it ideal for medical implant applications.
Complete Mechanical & Physical Properties – Tantalum (MPa / ksi)
Tantalum lock nuts are supplied in annealed condition per applicable ASTM specifications. Strain-hardened (cold worked) conditions available upon request. Data represent typical values based on industry standards.
Mechanical Properties – Tantalum (Annealed Condition)
Physical Properties – Tantalum
High-Temperature Mechanical Properties – Tantalum
Note: High-temperature testing in vacuum or inert atmosphere. Tantalum may embrittle in oxygen above 300°C.
High‑Temperature Performance of Tantalum Lock Nuts
Tantalum is a refractory metal with exceptional high-temperature strength and stability in vacuum or inert atmospheres. The material maintains useful mechanical properties up to 2000°C (3632°F) in non-oxidizing environments, making it suitable for extreme temperature applications in vacuum furnaces, rocket engines, and aerospace propulsion systems. Tantalum's melting point of 2996°C (5425°F) is among the highest of all metals, exceeded only by tungsten and rhenium. The recrystallization temperature of tantalum is approximately 1200-1400°C, depending on purity and prior cold work. In oxidizing atmospheres, tantalum forms a protective oxide layer (Ta₂O₅) at moderate temperatures but may embrittle above 300°C due to oxygen diffusion. Therefore, tantalum lock nuts are typically specified for high-temperature applications in vacuum, inert gas, or reducing atmospheres. All-metal flexloc designs are essential for high-temperature applications where polymer inserts would fail. Ta-2.5W alloy offers improved high-temperature strength compared to pure tantalum while maintaining similar oxidation behavior.
Elevated Temperature Capabilities
Exceptional Corrosion Resistance of Tantalum Lock Nuts
Tantalum is renowned for its outstanding corrosion resistance, often described as similar to glass but with the mechanical properties of a metal. The material forms a stable, adherent, and self-healing oxide layer (Ta₂O₅) that provides protection against virtually all acids and chemicals except hydrofluoric acid, hot concentrated alkalis, and fuming sulfuric acid (oleum). Tantalum exhibits zero or near-zero corrosion rates in most aggressive media, making it the material of choice for critical chemical processing applications where other materials fail.
Corrosion Resistance to Common Media
The following list represents media to which tantalum exhibits nil or negligible corrosion (rates <0.05 mm/year) at temperatures up to at least 150°C (302°F):
- Acetic acid
- Acetic anhydride
- Acetone
- Alcohols
- Aluminum chloride
- Aluminum sulfate
- Ammonium chloride
- Ammonium nitrate
- Ammonium phosphate
- Ammonium sulfate
- Aqua regia
- Barium chloride
- Benzoic acid
- Body fluids
- Boric acid
- Bromine (dry, <300°C)
- Butyric acid
- Calcium chloride
- Calcium hydroxide
- Carbolic acid
- Carbon dioxide
- Chloric acid
- Chlorinated brine
- Chlorine (dry, <250°C)
- Chlorine (wet, <350°C)
- Chloroacetic acid
- Chromic acid
- Citric acid
- Copper salts
- Fatty acids
- Ferric chloride
- Ferric sulfate
- Food stuffs
- Formaldehyde
- Formic acid
- Glycerine
- Hydrobromic acid
- Hydrocarbons
- Hydrochloric acid
- Hydrogen bromide (<400°C)
- Hydrogen chloride (<350°C)
- Hydrogen peroxide
- Hydrogen sulfide
- Lactic acid
- Magnesium chloride
- Magnesium sulfate
- Maleic acid
- Mercuric chloride
- Methyl alcohol
- Milk
- Mineral oils
- Mixed acids (sulfuric-nitric)
- Nickel salts
- Nitric acid
- Nitric acid (fuming)
- Nitric oxides
- Nitrogen (<300°C)
- Nitrous acid
- Organic acids
- Oxalic acid
- Oxygen (<300°C)
- Petroleum products
- Phenol
- Phosphoric acid (<4ppm F, <180°C)
- Pickling acids (except HNO3-HF)
- Potassium bromide
- Potassium chloride
- Potassium dichromate
- Potassium nitrate
- Potassium permanganate
- Potassium sulfate
- Propionic acid
- Refrigerants
- Sea water
- Silver nitrate
- Sodium acetate
- Sodium bisulfate (solution)
- Sodium bromide
- Sodium chlorate
- Sodium chloride
- Sodium cyanide
- Sodium dichromate
- Sodium hypochlorite
- Sodium nitrate
- Sodium nitrite
- Sodium phosphate
- Sodium silicate
- Sodium sulfate
- Sodium sulfide
- Sodium sulfite
- Sodium thiosulfate
- Stearic acid
- Succinic acid
- Sugar
- Sulfamic acid
- Sulfur (<500°C)
- Sulfur dioxide
- Sulfuric acid (<175°C)
- Sulfurous acid
- Tannic acid
- Tartaric acid
- Zinc chloride
- Zinc sulfate
Media to Avoid with Tantalum Lock Nuts
- Hydrofluoric acid (HF) – any concentration, any temperature
- Hot concentrated alkalis – sodium hydroxide (NaOH), potassium hydroxide (KOH) above 50°C
- Fuming sulfuric acid (oleum) – rapid attack
- Ammonium hydroxide – limited resistance
- Fluoride salts – may cause attack
- Hydrogen >300°C – may cause embrittlement
- Oxygen >300°C – may cause embrittlement
- Sulfuric acid >175°C – accelerated corrosion
Manufacturing Standards – Tantalum Lock Nuts
All tantalum lock nuts are manufactured and tested to meet the following standards:
We offer surface finishes: plain (as-machined), chemically cleaned, passivated, or electropolished for medical applications. Controlled annealing processes per ASTM specifications ensure consistent mechanical properties. Specialized CNC machining and tapping for accurate lock nut geometry with reliable self-locking torque values. All-metal flexloc designs feature segmented collars that meet military standards for 15 cycles of prevailing torque. Class 2B/3B/6H thread fit. 100% inspection available including dimensional inspection, proof load testing, and non-destructive examination. Full traceability and material test reports (MTR) with mill certifications available. AS9100 and ISO 9001:2015 certified quality management. ISO 13485 certified for medical applications with cleanroom packaging available. Build-to-print specials to customer specifications are available.
Why RAYCHIN LIMITED – The Tantalum Lock Nut Authority
Contact the tantalum lock nut experts
Request a quotation for tantalum lock nuts, self-locking nuts, prevailing torque nuts – any standard (ISO, DIN, ASME, NAS, MS) – any condition (annealed, stress-relieved) – any locking style (all-metal flexloc, polymer insert, elliptical) – any quantity. Global delivery. Mechanical and corrosion data in MPa/ksi available for all products. Medical-grade tantalum per ASTM F560 available.
sales@ray-chin.com | +86 534 2166 566Our team provides technical support in English, German, Mandarin, Japanese. Request a quote, sample requests, and material evaluation available.
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