Toyo-Sasaki's signature Hard Strong glass-strengthening technology was developed in 1967 and continues to be popular for its durability. They are also dishwasher safe.
Testimony by an Umami Mart customer:
“I dropped a Hard Strong glass on my granite counter top, then it bounced into my steel sink and nothing happened! I saw it with my own eyes in slow motion, sure it was going to shatter during the tumble. These are truly Hard Strong!”