GLESTAIN (←Logo) GLESTAIN steel based on 440A undergoes several stages of special heat treatment, including sub-zero treatment (ultra-low temperature treatment). We have achieved advanced functions by thoroughly pursuing quality such as corrosion resistance, abrasion resistance, heat/cold resistance, toughness (strength), hardness stability (HRC 58 to 59 degrees), and durability of sharpness. Features of Gresten TM type. By allowing air to enter the recessed part, we have achieved good blade separation and light cutting ability. Hygienic and durable stainless steel handle made of 18-8 stainless steel. It's easy to clean, doesn't rust, and doesn't smell, so it's hygienic.