This is a penetrating oil formula containing a high level of red dye has very low surface tension and excellent wetting which allows ink to deep penetrate into potenital surface cracks or flaws otherwise undetected by the naked eye
The red dye is specifically chosen for its good visibility in natural, artificial light or ultra violet light.
All requirements called for by the A.S.M.E. (American Society of Mechanical Engineers) in their publication section N article 6 T650, T661, T662, T664 is complied with in all respects