colourless layers	coloured layers	optimal corrosion protection	Stabilization
Friction value adjustment
Product	Use as separate post-treatment	Use as additive for sealing SurTec 555	available documents
SurTec 521	•	•	Product Info
Friction value on chromited Zinc:	0.11	0.13	Measuring minutes
Effect on corrosion protection:	clear increase until first attack decrease of surface corrosion increase until red-rust	+ 100-200 h until first attack clear increase until red-rust
SurTec 520	•		Product Info
Friction value on chromited Zinc:	0,10-0,11		Measuring minutes
To compare:	Chromiting Zinc without after-treatment	chromited Zinc with SurTec 555	Product Info
Friction value:	0,29-0,32	0,14-0,15