This is the one. The title is "The Three Nails" (not "The Three Rusty Nails").

THE THREE NAILS
By Lewia Harrah & Jimmie Davis (1970)

1.
With three rusty nails, they nailed Jesus to the tree.
The sun turned to darkness on that day.
'Twas the day that Jesus died, and the blood flowed from His side,
The blood that washed my sins away.

2.
Jesus cried, "Forgive them Lord, for they know not what they do,
For they have strayed so far, far away."
With three old rusty nails, they took Jesus' precious blood,
The blood that washed my sins away.

3.
They laughed as He cried, soldiers pierced His naked side.
And His Father turned His face away.
They drove the nails so deep, spilled His blood and made Him weep;
The blood that washed my sins away.

(Source: Gospel & Inspirational Showstoppers, CPP/Blewin, 1992, p. 92; with music & chords)

~Masato