Commonly used values for  are ~5 or greater, although more precise values are usually obtained by fitting of tensile (or compressive) experimental data.
kˈɑːmənli jˈuːzd vˈæljuːz fɔːɹ ɑːɹ tˈɪldə fˈaɪv ɔːɹ ɡɹˈeɪɾɚ, ɔːlðˈoʊ mˈoːɹ pɹɪsˈaɪs vˈæljuːz ɑːɹ jˈuːʒuːəli əbtˈeɪnd baɪ fˈɪɾɪŋ ʌv tˈɛnsəl ɔːɹ kəmpɹˈɛsɪv ɛkspˌɛɹɪmˈɛntəl dˈeɪɾə.