PYREX® Square Bottles, Graduated, Corning® Supplier: Corning PYREX borosilicate glass provides exceptional chemical and thermal resistance. Autoclavable When used with a PBT high-temperature cap and ETFE pouring ring ( 16157-497, see 16157-071 series), bottles can withstand repeated sterilization cycles up to 180 °C (356 °F) dry heat.