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Ardrox Penetrant Testing for Aerospace 

Through our partner Chemetall, Silmid are able to offer a wide variety of chemicals suitable for NDT in the aerospace industry. A full overview guide can be found here with additional details below. 


Fluorescent Water-Washable Penetrants (surfactant based) 

Ardrox 970P24E, Ardrox 970P25E and Ardrox 970P26E are biodegradable water-washable fluorescent penetrants offering a range of sensitivity levels. 

The basis for this penetrant development is a mixture of biodegradable surfactants and fluorescent pigments without any mineral oils or hydrocarbons. 

All products are approved to AMS 2644. 

Product  AMS 2644 Sensitivity Level  
Ardrox 970P24E   2
Ardrox 970P25E  3 
Ardrox 970P26E  4

Fluorescent Water-Washable Penetrants (solvent based)

Ardrox 970X series represents Chemetall’s new generation of state-of-the-art, water-washable fluorescent penetrants. Based on the latest surfactant technology (free of Nonylphenolethoxylate, (NPE)) all products have low-odour, low toxicity and have therefore a minimal impact on the environment. 

The new Ardrox 970X series gives crisp indications with exceptionally low levels of background and have excellent heat and UV fade characteristics.
All products are fully approved according to AMS 2644. 

Product  AMS 2644 Sensitivity Level  
Ardrox 9702   1
Ardrox 9703 2
Ardrox 9704 2
Ardrox 9715  3

Fluorescent Post-Emulsifiable Penetrants 

Chemetall has developed a new range of Ardrox high performance, post-emulsifiable, fluorescent penetrants that utilizes the latest surfactant technology (NPE-free).  

The new Ardrox 981X series of products have low-odour, low toxicity, high flash point, minimal environmental impact and show significant performance improvements compared to older generation products.  

To complement this new range of penetrants, Ardrox 9881, a new hydrophilic emulsifier with improved odour control and bath stability, has also been developed. All products are fully approved according to AMS 2644.  

Product  AMS 2644 Sensitivity Level  
Ardrox 9812    2
Ardrox 9813 3
Ardrox 9814  4
Ardrox 9881 Hydrophilic Emulsifier 

Red Dye Penetrants 

Ardrox 907PB is a water-washable and solvent-removable red dye penetrant, Ardrox 996PB is a solvent-removable red dye penetrant (please also refer to Ardrox 9PRx series).  

Ardrox 9VF2 is a water-washable fluorescent colour contrast penetrant (dual purpose according to EN ISO 3452-2 Type III). The inspection can therefore be done under white light but improved indication of defects is possible by means of an ultraviolet light.  

Ardrox 9VF2 is a high sensitivity azo-dye free penetrant which does not contain any aromatic hydrocarbons. 

Product  Description  
Ardrox 907PB   Water-washable 
Ardrox 996PB  Solvent-removable 
Ardrox 9VF2 Water-washable/Solvent-removable 

Penetrant Removers/Cleaners 

Ardrox 9PRX products are colourless, highly volatile, solvent based penetrant removers. They are fast drying and have a low sulphur and halogen content. 

All products are mainly used for the removal of both visible red dye and fluorescent penetrants. They can also be used as a solvent pre-cleaner prior to the penetrant application for the removal of oil and grease. 

Please note the following Flash Point values: 

Product  Flash Point  
Ardrox 9PR5     - 4°C 
Ardrox 9PR50 > 38°C 
Ardrox 9PR88 10°C 


Ardrox developers are based on very fine white powder with a defined particle size range and exhibit advanced absorption properties. They ensure superior white film background for better visibility of indications. All developers can be removed easily after inspection. Ardrox developers hold major approvals such as AMS 2644, Pratt & Whitney, Safran Group or MTU. 

Depending on the application several developer types are available, including non-aqueous wet developer, dry powder, water suspendable or water soluble products. 

Product  Description  
Ardrox 9D4A   Form A – Powder developer 
Ardrox 9D1B Form D – Solvent based 
Ardrox NQ1   Form D – Solvent based