I do not have any coffin nails as I have not been grave digging since, well...... ever. But I did find something you might find interesting and perhaps more powerful. Please continue reading.
The Peavy Globe Grain Elevator in Superior Wisconsin, built in 1887 located in the West Gate Basin and Howards Bay later known as the Old Globe Grain Elevator. At the time it was constructed it was the largest grain elevator constructed in the world. It was built during 1887-1894 and had numerous inexplicable deaths during the construction and some say it was cursed. It was demolished in the year 2000. The nails I have to offer you are from the original build after it was demolished.
Many stories have been passed down over the ages about this Grain Elevator and some say it was cursed. Among the inexplicable deaths that have not been formerly documented, the stories keep these myths alive. Grandparents and parents told their children never to go near the place, as they feared they would never see them again. Very strange accidents and disappearances took place during and after its build. Many were relieved once this facility was demolished in 2000.
Many will never forget the warnings. There is much power in these nails as folklore has attached itself to every piece that remains and deemed cursed.
Historically, coffin nails are known for their ability to add potency to your magic, particularly curses. Spells are documented to gain potency when coffin nails are used in a ritual or spell. They are mostly used towards enemies that you want to focus on things besides you. They are also used for binding, hexing and in the combination of the infamous Nine Nails Druidic Curse Spell. These nails are for advanced practitioners and should not be used by beginners. Please be careful with your intentions, as some things cannot be undone.