Coffin with Metal Nails

Is it permitted to use a coffin that has metal nails ?

Shalom!

Thank you for your question.

It is definitely preferable that the coffin used for a Jewish deceased be a plain pine coffin held together with wooden dowels. The source for this is the Midrash Rabba 19:8 which connects Adam and Eve having hidden among trees to wood coffins in which their descendants would be buried in.

If there are no wooden nails to be found one should not delay a funeral over this issue. However if the only coffin available is a more elaborate looking coffin as is common among the non-Jews, then one should wait a little time in order to get a plain coffin, but one shouldn't wait too long.

This is because although keeping with Jewish tradition as it applies to coffins is important, it is even more important to have the deceased buried as soon as possible, preferably the same day as the death. It is, in fact, a Torah obligation to bury someone on the day they die. In the event that the options are a plain pine coffin with metal nails or an all wooden elaborate coffin without any metal, the non-metal option is to be preferred.

The aversion to having metal in coffins is primarily due to the association with metal and warfare which we often try to avoid in the performance of mitzvot. There are also reasons related to purity and impurity which are beyond the scope of this answer. Nevertheless, there is no true source forbidding metal nails in coffins. Indeed, historically the Russian and Lithuanian communities were not overly particular about it while Polish and Hungarian Chassidic communities were. The custom became like the Chassidim.

It is worth noting that burial in a coffin is the custom outside of the land of Israel where the governments of most countries require that burial take place in a coffin. In Israel, however, burial is generally done without a coffin in order to better comply with “From dust you are and to dust you shall return.”

YD 362 with commentaries.