Threadlocking

About Threadlocking

Threadlocking adhesives are essential chemical fastening solutions designed to prevent nuts, bolts, screws, and other threaded fasteners from loosening due to vibration, thermal cycling, or mechanical stress. These anaerobic adhesives cure in the absence of air between closely mating metal surfaces, forming a robust bond that secures threaded connections whilst still allowing controlled disassembly when required. Whether you're working on automotive repairs, machinery maintenance, or construction projects, threadlocking compounds provide reliable insurance against fastener failure that could lead to costly downtime or safety hazards.

At TooledUp.com, our threadlocking range includes products from trusted brands including Bondloc, Draper, Sealey, J-B Weld, and Everbuild. These products are available in three standard strength grades – low, medium, and high – each formulated for specific applications and disassembly requirements. Low strength threadlockers (typically blue in colour) are ideal for small fasteners and applications requiring regular adjustment. Medium strength formulations (usually green or blue) suit general-purpose applications and can be removed with hand tools. High strength threadlockers (red) create permanent bonds for critical applications where fasteners should rarely or never be disassembled.

Modern threadlocking compounds offer numerous advantages over traditional mechanical locking methods such as lock washers, nylon inserts, or lock nuts. They fill the entire gap between threads, distributing load evenly and protecting against corrosion whilst taking up no additional space. This makes them particularly valuable in compact assemblies or where weight and space are at a premium. Professional tradespeople and serious DIY enthusiasts rely on threadlocking adhesives to ensure their work remains secure and dependable long after the initial installation.

Jargon Buster

• Anaerobic Adhesive: A type of adhesive that cures (hardens) in the absence of oxygen when confined between close-fitting metal surfaces. Threadlockers are anaerobic adhesives that remain liquid until applied to threaded fasteners.
• Breakaway Torque: The amount of rotational force required to loosen a fastener that has been secured with threadlocker. This measurement helps determine whether a fastener can be removed with standard hand tools or requires heat application.
• Prevailing Torque: The continuous torque required to keep a fastener rotating once it has been initially loosened. This differs from breakaway torque and indicates how effectively the threadlocker maintains resistance throughout removal.
• Fixture Time: The period required for a threadlocker to develop sufficient strength to handle the assembly. During this time, parts should not be disturbed. Fixture times vary by product and temperature but typically range from 10 minutes to several hours.
• Service Temperature Range: The minimum and maximum temperatures at which a cured threadlocker maintains its locking properties. Most standard threadlockers perform effectively between -55°C and +150°C, though high-temperature formulations are available for specialist applications.
• Wicking Grade: A low-viscosity threadlocker designed to penetrate pre-assembled fasteners through capillary action. These products are applied after assembly rather than during initial fitting, making them ideal for remedial work on existing connections.

Who Uses Threadlocking?

Threadlocking products are essential for a wide range of professional tradespeople and industries:

• Mechanical Engineers and Fitters: Securing critical fasteners on industrial machinery, pumps, gearboxes, and production equipment
• Automotive Technicians: Preventing loosening of engine components, suspension fasteners, brake assemblies, and exhaust systems
• Plant Maintenance Teams: Maintaining reliability of rotating equipment, conveyors, and processing machinery in manufacturing facilities
• Agricultural Engineers: Securing fasteners on tractors, harvesters, and farm equipment subject to constant vibration
• HVAC Installers: Locking connections on heating systems, ventilation units, and air conditioning equipment
• Electrical Contractors: Securing terminal connections, cable glands, and mounting hardware in control panels and distribution boards
• Construction Workers: Preventing loosening of scaffold fittings, formwork connections, and structural fixings on site work
• Marine Engineers: Protecting threaded connections from vibration and corrosion in boat engines and deck equipment
• Bicycle and Motorcycle Mechanics: Securing critical fasteners on frames, engines, and suspension components
• DIY Enthusiasts: Ensuring reliable connections on home repairs, workshop projects, and garden equipment maintenance

How to Choose the Right Threadlocking

Selecting the appropriate threadlocker depends on several critical factors:

Thread Size: Low strength threadlockers are recommended for small fasteners up to M12, as they prevent damage to fine threads during removal. Medium strength products suit fasteners between M6 and M20, whilst high strength formulations are designed for larger bolts and studs from M12 upwards where permanent assembly is required.

Disassembly Requirements: Consider how often you'll need to remove the fastener. Low strength (blue) threadlockers permit easy disassembly with standard hand tools and are ideal for adjustable components. Medium strength (green/blue) products require normal hand tools but more effort to remove. High strength (red) threadlockers create permanent bonds requiring heat (typically 250°C) for disassembly and may damage some components during removal.

Application Environment: Standard threadlockers perform well in most conditions, but specialist formulations exist for extreme temperatures, chemical exposure, or outdoor applications. Check the service temperature range matches your requirements – particularly important for exhaust systems, engines, or equipment operating in cold storage environments.

Material Compatibility: Whilst most threadlockers work excellently on steel fasteners, some metals like stainless steel, aluminium, or brass may cure more slowly. Certain products include activators or primers to improve performance on inactive metal surfaces or plastics.

Brand Selection: Professional brands like Bondloc, J-B Weld, and Sealey offer reliable performance with consistent quality. Their product numbering often corresponds to industry-standard specifications (such as 222, 243, and 270 designations) making it straightforward to select equivalent products across different manufacturers.

Bottle Size and Applicator: Consider how frequently you'll use threadlocker. Smaller bottles suit occasional use and have longer shelf life once opened, whilst larger bottles offer better value for workshop or site environments with regular applications.

Popular Accessories

• Surface Activators and Primers: Accelerate cure times on inactive surfaces and improve performance on non-ferrous metals, plastics, and plated fasteners
• Degreasing Solvents: Clean fasteners before threadlocker application to ensure maximum bond strength by removing oil, grease, and contamination
• Threadlocker Removal Tools: Specialist solvents and heat guns designed to break down cured threadlocker for fastener removal and thread cleaning
• Torque Wrenches: Essential for applying correct tightening torque before threadlocker cures, ensuring proper fastener preload
• Thread Repair Kits: Helicoil and thread insert sets for repairing damaged threads before applying threadlocker
• Pipe Sealants: Complementary products for sealing tapered pipe threads whilst providing anti-seize properties
• Gasket Makers and Sealants: Anaerobic flange sealants and instant gaskets for complete sealing solutions alongside threadlocking
• Retaining Compounds: Cylindrical assembly adhesives for securing bearings, bushings, and cylindrical parts

Safety Information

Threadlocking adhesives are chemical products that require proper handling and storage to ensure safe use:

Personal Protection: Always wear appropriate safety glasses to protect eyes from splashes. Nitrile gloves prevent skin contact, which can cause irritation or sensitisation in some individuals. Work in well-ventilated areas to avoid breathing vapours, particularly important when applying larger quantities or working in confined spaces as required under COSHH regulations.

Skin Contact: If threadlocker comes into contact with skin, do not attempt to pull bonded skin apart. Instead, soak in warm soapy water and gently peel apart. Cyanoacrylate-based products (superglue) may accidentally bond skin – keep acetone-based nail polish remover nearby as a precaution, though most threadlockers are less aggressive.

Storage Requirements: Store threadlocking products in cool, dry conditions away from direct sunlight. Keep bottles tightly sealed between uses to prevent premature curing. Most products have shelf lives of 12-24 months when stored correctly. Check expiry dates before use as aged products may have reduced performance.

Fire Safety: Threadlockers are generally non-flammable once cured, but liquid products should be kept away from naked flames and heat sources. When removing high-strength threadlockers with heat, be aware of fire risks from nearby materials and ensure adequate fire safety precautions are in place.

Disposal: Dispose of empty containers and waste material according to local authority regulations. Never pour unused threadlocker down drains. Consult product safety data sheets (available from manufacturers) for specific disposal requirements and environmental considerations.

Frequently Asked Questions

Can I use threadlocker on stainless steel fasteners?

Yes, threadlocker works on stainless steel, though it may cure more slowly than on mild steel due to the inactive surface. For best results, consider using a surface activator or primer, particularly with austenitic stainless grades. The anti-corrosion properties of threadlocker are particularly valuable on stainless steel as they prevent galling – a common problem where stainless threads seize together.

How long should I wait before putting an assembly into service?

Fixture time varies by product and temperature but typically ranges from 10 minutes to 3 hours for handling strength. However, full cure takes 24 hours for maximum strength. Low strength threadlockers generally fixture faster than high strength products. Working at room temperature (20-22°C) provides optimal cure speeds – cold conditions significantly extend cure times.

What's the difference between blue and red threadlocker?

Blue threadlocker is low to medium strength, designed for fasteners requiring regular maintenance or adjustment. It allows disassembly with standard hand tools. Red threadlocker is high strength, creating permanent bonds for critical applications. Removal typically requires heating to approximately 250°C, which may damage some components. Choose blue for serviceable connections and red for permanent assemblies.

Will threadlocker damage plastic components?

Most anaerobic threadlockers are compatible with common engineering plastics and won't cause damage, as they only cure in the absence of oxygen between metal surfaces. However, some aggressive solvents in certain formulations might affect sensitive plastics. Always check manufacturer compatibility information, and consider using specialist plastic-safe threadlockers for critical applications involving nylon, acetal, or other engineering polymers.

Can I apply threadlocker to fasteners that are already installed?

Yes, using wicking grade threadlockers specifically designed for this purpose. These low-viscosity products penetrate pre-assembled threads through capillary action when applied around the nut-bolt interface. This makes them invaluable for remedial work or situations where disassembly isn't practical. However, for best results, always clean threads and apply threadlocker during initial assembly when possible.