Grodal Rapid Salt Description It is an additive for water quenching systems that eliminates soft spots occurring in water. Application: Grodal Rapid Salt solutions are suitable for quenching plain carbon and low alloy structural and water hardening tool steel. The Growel Advantage: Readily water-soluble. Corrosion Protection for work. Optimum and Uniform hardness. Less distortion. Wide concentration range control get a quote