Shiva Purana
प्रमाणमंगुलस्यैकं तदूर्ध्वं पंचकत्रयम् । अयोदारुकृतं पात्रं शिवमित्युच्यते बुधैः १३ ।
The measurement of one finger's width (angulasyekaṃ), and above that, three times five (panchakatrayam) is considered as the measurement for a metal vessel made of iron or wood. This is called a Shiva vessel, according to the learned (buddhaiḥ).
english translation
pramANamaMgulasyaikaM tadUrdhvaM paMcakatrayam । ayodArukRtaM pAtraM zivamityucyate budhaiH 13 ।
hk transliteration by Sanscript