Loctite Colours Explained: Which One Do You Need?
Loctite is a well-known brand of threadlockers and retaining compounds, used by mechanics, engineers and tradespeople across many industries. But with so many colours on the shelf, it's easy to grab the wrong one. This guide explains the colours of common Loctite grades, so you can choose a suitable product for the job.
How the colours work
Colour is a useful starting point, not a complete specification. In the threadlocker examples below, purple is low strength, blue is medium strength and red is high strength. Green 290 is a wicking threadlocker, but other green Loctite products can be high-strength threadlockers or retaining compounds. Always check the product number, not just the colour.
Use the image as an overview only. The product-specific guidance below and the current Henkel technical data sheet take precedence.
Quick pick
| Colour and example | Type | Strength | Removal | Typical use |
|---|---|---|---|---|
| Purple: 222 | Threadlocker | Low | Hand tools | Small fasteners and adjustment screws |
| Blue: 243 | Threadlocker | Medium | Normally hand tools | General-purpose locking with future servicing in mind |
| Red: 263 / 271 | Threadlocker | High | Plan for heat-assisted disassembly; follow the exact grade's instructions | High-strength locking where routine disassembly is not intended |
| Green: 290 | Wicking threadlocker | Medium–high | Follow the data sheet; heat may be needed | Pre-assembled threaded fasteners |
| Silver: LB 771; grey: LB 8009 in its technical data sheet | Anti-seize lubricant | Not a threadlocker | Intended to help later disassembly | Protection against galling and seizure in suitable applications |
Choose by the application, materials, required strength and future disassembly needs. The colour groups are not bolt-size bands or a universal scale across all Loctite products.
Purple: low strength (Loctite 222)
Best for: small threaded fasteners and adjustment screws where low-strength locking and easy disassembly with hand tools are needed.
222 helps prevent loosening from shock and vibration while allowing removal with standard hand tools. Typical applications include adjustment screws, countersunk screws and set screws. Check suitability for the fastener and assembly rather than selecting by diameter alone.
Blue: medium strength (Loctite 243)
Best for: general-purpose locking of metal bolts and nuts where future disassembly with hand tools is important.
243 helps secure threaded fasteners against vibration and shock. It is an oil-tolerant grade, but that is not a reason to leave threads dirty: clean and prepare the surfaces as directed in its technical data sheet.
Red: high strength (Loctite 263 / 271)
Best for: metal bolts, nuts and studs requiring high-strength locking, where routine disassembly is not intended.
These grades are designed for permanent locking of threaded fasteners. “Permanent” does not mean impossible to remove, but you should plan for more difficult disassembly and possible heating. Follow the exact grade's removal instructions and confirm that the assembly can safely tolerate the required procedure.
Do not select red solely because a joint is important or a bolt is large. Follow the equipment manufacturer's requirements. Threadlocker does not replace correct joint design or tightening.
Green: wicking grade (Loctite 290)
Best for: suitable threaded fasteners that are already assembled.
290 is a thin, medium-to-high-strength threadlocker. Its capillary action lets it wick between engaged threads without disassembly before application. Follow its surface-preparation and application instructions; it is not a way to compensate for contamination.
Do not mistake its thin consistency for low strength. Its technical data sheet describes removal with hand tools and heat-assisted removal where necessary. Check the instructions for your product and assembly.
Not every green Loctite product is a wicking threadlocker. For example, green retaining compounds are intended for different joint types. Read the product number.
Silver / grey: anti-seize, not threadlocker
Examples: Loctite LB 771 and LB 8009.
These are non-curing lubricants, not adhesives for locking threads. LB 771 is a silver, nickel-based anti-seize. The LB 8009 technical data sheet describes a grey paste, while Henkel's product Page lists black, another reason to identify the product by number rather than colour alone.
Anti-seize can help prevent galling and seizure and assist later disassembly after exposure to heat or corrosive conditions. Choose the formulation for the metals, temperature and operating environment.
Watch the torque: lubrication changes thread friction. The same tightening torque can produce a higher clamp load than on dry threads. Follow the equipment manufacturer's instructions for the specified lubricant and tightening procedure. Do not assume anti-seize belongs on every fastener.
What about press fits?
Bearings, bushes, sleeves and other cylindrical joints generally call for a suitable retaining compound, not a threadlocker selected by colour. Henkel distinguishes retaining compounds for cylindrical fitting parts from threadlockers for threaded fasteners. Select according to the joint design, clearance, operating conditions and disassembly requirements.
Tips for best results
- Clean and prepare the surfaces. Follow the exact grade's instructions, even when it is described as oil tolerant.
- Apply the specified amount in the right place. Through-holes, blind holes and pre-assembled joints can require different application methods. Do not use a universal “few drops” rule for every joint.
- Allow the required cure time. Fixture time is not the same as full cure. Cure depends on the grade, substrate, temperature and joint gap; follow the technical data sheet before putting the joint into service.
- Use an activator only as directed. A suitable activator may be needed for slow-curing conditions. The grade's instructions determine which one to use and how to apply it.
- Check material compatibility. The threadlocker data sheets warn against normal use on plastics, particularly thermoplastics that may stress-crack. Confirm compatibility before use.
- Tighten correctly. Threadlocker does not replace the equipment manufacturer's tightening instructions.
- Check storage and handling instructions. Follow the label, technical data sheet and safety data sheet for the exact product.
Need help choosing?
Contact BOLD Industrial & Domestic Solutions Ltd for help choosing a suitable Loctite grade and confirming availability.
Manufacturer references
This guide uses Henkel's product guidance and technical data sheets. Always use the current instructions for the exact product supplied.