The (tensile) strength-size scaling of a float-soda-lime-silicate glass was studied using biaxial flexure & Hertzian ring crack initiation testing. The examined Weibull effective areas spanned ~0.4-48,000mm2. Both the air & tin sides were tested. The air side was stronger than the tin side as others have observed; however, the differences in their characteristic strengths decreased with a decreasing effective area & their strengths converged for effective areas smaller than ~100mm2. The failure stress at the smallest effective area examined for the tin side was ~500% greater than that at the largest effective area, while that difference was ~250% for the air side. A Weibull modulus change at ~100mm2 suggests different strength-limiting flaw types were dominant below & above this effective area. Results reinforce the importance of the interpretation & use of the tensile strength of glass in context to how much of its area is being subjected to tensile stress.
