Crown Salt (H) (25 lb Pail)

High quality mixture of potassium nitrate with silicic acid for chemical hardening of crown glass lenses in a 16-hou process.  Can also be used for new generation photo gray lenses in a 2-hour process.

Chemtempering strengthens glass lenses by producing a compressive stress in the lens surface.  This process increases compressive stress by exchanging large sodium ions (in the lens) for smaller, more compact, potassium ions (from the tempering salts).  This compression makes the leses stronger becasue any applied tension must now be over come the built-in compression before the surface itself can be put in tension.  Tension is the only kind of stress that can causes glass to break.

Why Shop Salem?

For 90 years, Salem Fabrication Supplies has become a trusted source for optical lab industry supplies.  Our focus is squarely on meeting customer needs with industry expertise, quality products and knowledgeable service.  When you choose Salem, you're tapping into nearly a century of reliability and experience.  Shop with confidence at Salem Fabrication Supplies.

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