Assigned By Sterling Seal Supply 030 Polyurethane O-Ring, 70A, Pack Of 18 Product Details This O-ring is made of translucent polyurethane and has a durometer of 70A. It has a round cross-section and can be used across a wide temperature range (-60 degrees F/-51 degrees C to 212 degrees F/100 degrees C). Designed for use in a wide variety of sealing applications, this polyurethane O-ring meets standards defined by Aerospace Standard AS568A, which is the Aerospace Size Standard for O-rings. Polyurethane is resistant to oil, weather, ozone , heat, electricity, abrasion, tearing and many chemicals. It performs well in low temperatures, but is not recommended for continuous use in high temperatures or with super-heated steam. The durometer hardness of this polyurethane O-ring is 70A. Durometers measure the hardness of a material and its resistance to permanent indentation. A higher durometer value indicates greater resistance to indentation. On a scale of 0 to 100, a value of 0 indicates that a sample was completely penetrated, while a value of 100 shows no indentation in the sample. The letter following the number identifies the shore scale, which is either shore A or D. Shore A is used for softer plastics, while shore D is used for harder plastics. O-rings provide a pressure and fluid seal between cylindrically shaped, overlapping mating surfaces and are commonly seen in engines, faucets, flanges, valves, and various cylinders. They are circular in shape, with a round cross section, and a hole in the center, similar to a doughnut. O-rings are available in various AS568A dash sizes, which is the standardized sizing for O-rings, and defines the nominal inside diameter (ID), outer diameter (OD), and cross-sectional (CS) diameter of an O-ring. Urethane O-Rings are compatible with hydraulic fluids, weak acids and bases, and mixtures containing less than 80 percent aromatic constituents Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.