Yes, WEICONLOCK AN 302-43 can be used with a stainless steel screw and a part made of Grivory GV-5H (glass fibre reinforced polyamide), but the curing and final strength depend on the stainless steel surface and the fact that the mating material is plastic. You should expect slower/reduced curing on stainless steel and test the strength and safety in your application. It cures when enclosed in the thread gap and comes into contact with metal ions. The TDS explicitly states: "In the absence of oxygen and in contact with metal ions ..."
The TDS also shows that stainless steel is a less reactive substrate (the reaction/curing is slower than with zinc or brass) and lists lower breakaway/locking torques for stainless steel (breakaway torque for V2A ≈ 9.2 Nm, V4A ≈ 17.8 Nm).
Effect of the black coating on the screw This depends on the type of coating: If the black coating is a thin inorganic black oxide layer or a porous black phosphate layer, anaerobic curing is usually still possible after assembly (metal ions available). Curing is slower on stainless steel, but is usually sufficient.
If it is an organic coating, heavy oil/film, paint or an inert coating that blocks contact with metal ions, the curing of the adhesive may be inhibited or greatly slowed down, reducing its strength. Recommendation: Remove oil/contaminants and, if possible, identify or test the coating. Cleaning with WEICON Surface (or a suitable solvent) improves reliability. Effect of the plastic (Grivory GV-5H)
Grivory GV-5H is a glass fibre reinforced engineering plastic (polyamide type). Plastics do not usually provide metal ions for curing; the screw (metal) is the active partner that provides the ions. If the screw thread is mainly in contact with plastic (metal screw in plastic component), the adhesive will still cure in the limited thread gap, as the metal screw provides the necessary activation. However, the final bond strength is usually lower than with a metal-metal connection, and curing may be slower. Some plastics (e.g. PTFE, PE, PP, silicones) can prevent curing. Grivory is not one of them, but you should still check whether your exact material quality and mould additives (plasticisers, release agents) can influence curing. Practical recommendations (what to do next)
Cleanliness Degrease both parts (WEICON Surface or isopropanol) and remove oils/packaging lubricants from the screw and the plastic thread area. Use Activator for faster/more reliable curing on stainless steel The TDS lists Activator F as an accessory and shows that it increases the reaction/curing speed. For stainless steel and other poorly active metals, an activator usually helps to achieve faster and more complete curing.
Test Activator F on spare parts first – some activators can attack plastics, so check that no cracks or damage occur. Application and assembly Apply AN 302-43 to the screw thread (or as recommended in the TDS: in circles to seal). Assemble the product while wet and allow it to take effect. Observe the product limits: gap ≤ 0.25 mm, handling strength 10–20 min, final strength 1–3 h (TDS values), temperature and chemical exposure limits.
Test Perform a small qualification test: install test screws in Grivory parts, measure the breakaway/locking torque and/or pull-out strength after the recommended curing times and after 24–72 hours. Also test the disassembly method – products with medium strength may cause damage to the plastic when loosened. If the results are not satisfactory, try Activator F on the screw (or on both surfaces if this is safe for the plastic).
Consider using a product specifically designed for thread locking on plastic if you require higher, predictable strength for plastic substrates. Safety note Do not return cured/contaminated product to the bottle (TDS warning). Follow the safety and SDS instructions.