Every nail has different characteristics – from the material it is made of, to the size and shape, these attributes contribute to the shear strength of a nail. The most widely used type of nail is the common wire nail which is created out of steel. It has an impressive weight carrying capacity of 60psi per square inch – this means that for each inch of length, it can hold up to 60 pounds before it succumbs to its load and gives way.
Steel is the popular choice for making common smooth nails, which possess a shear strength of around 80 pounds per square inch. If we translate that into practical terms, it means that these nails, which are an inch in length, can tolerate holding up a weight of up to 80 pounds before they crack.
The third most regularly encountered nail is the common screw type which can be made of either brass or steel. Its shear strength is calculated around 100 psi, enabling it to carry an impressive weight of a hundred pounds in a single inch.
Coming in at fourth place is the regular old steel ring nail that you can find in most home improvement stores. Its strength is nothing to laugh at, with a shear capacity of a whopping 120 pounds per square inch. That means one of these 1-inch nails is capable of withstanding a hefty 120-pound load till it finally gives in.
Steel is used to make the fifth most frequently encountered type of nail: the common square nail. This type of nail has a shear strength of 140 psi – meaning that it can sustain up to 140 pounds of weight before being unable to endure any further stress and breaking. This can be visualized by imagining a single inch-long nail holding a massive 140-pound weight!
Ultimately, the shear strength of a nail greatly relies on its form, size, and composition. The common wire nail is the most common type and its shear strength is 60 psi, followed by the smooth nail which can reach up to 80 psi. Moving up in force, the screw nail can persevere with 100 psi, while the ring nail has a peak shear strength of 120 psi. Last but not least is the square nail that takes the cake with a commendable shear strength of 140 psi.