a metaphorical instruction which assumes similarity among fastening any ends using any means
Consider what is to be fastened, how strong their materials are: how may they hold or reject the fastener, how the materials may naturally cling or repel another or the fastener.
Will the material render the fastener inaccessible after fastening?
Strength & Durability
Consider the strength of the bond. Will it need to be dissolved and reinstated continually, or always hold fast?