WD-40 – Specialist Penetrant – Technical Data Sheet

Function
Low‑viscosity penetrant to creep through oxide layers and free seized fasteners and interfaces.

Key points

• High wetting and capillary action; undermines rust bridges.
• Moisture displacement; leaves a light protective film.
• Allow dwell on heavy corrosion; use tapping to accelerate ingress.

Usage

• Expose as much surface as possible; remove loose scale.
• Apply and wait; work the joint gently to distribute fluid.
• Protect freed parts with longer‑term lubricant.

Cautions

• May soften certain elastomers; avoid overspray on finishes.
• Use ventilation; respect flammability guidance in the PDF.