The physics of nails holding weight: Why do nails at a 45-degree angle support weight? The Mechanics of Nails
It might be difficult to choose the ideal location to attach large objects to a wall. Conventional techniques, including utilizing screws and anchors, can be labor-intensive, expensive, and can harm the wall. Here is where HangSmart comes in. We provide a do-it-yourself TV wall mount that just requires nails, can be mounted at a 45-degree angle, and doesn't require wall studs.
However, why is a nail at a 45 degree angle so crucial? Let's examine the physics in more detail.
You essentially build a cantilever beam when you hang something on the wall—a long, narrow beam that is fastened at one end and supported at the other. The force that the object's weight produces on the wall is transferred to the wall itself via the mounting hardware. By distributing the force across the wall as evenly as possible, you may ensure that the object remains firmly in place.
The 45-degree angle is useful in this situation. A shear force is produced when a nail is driven into a wall at a 45 degree angle and is dispersed over a larger region of the wall. By doing this, the possibility of the nail coming out or the wall collapsing under the weight of the object is decreased. Also, the nail's slant aids in locking it into place and serves as a reliable anchor for the mounting hardware.
Driving a nail into a drywall at a 45-degree angle increases its ability to bear weight due to a couple of reasons.
1. Shear Force Distribution: When you drive a nail into the drywall at an angle, it distributes the force along the length of the nail more efficiently than driving it straight. This is because an object hung on the nail applies a downward force that tends to pull the nail out. However, a nail angled upwards has to be sheared or cut off, not just pulled out, making it harder for the object to fall. This essentially means there's more friction between the nail and the drywall, which can resist the nail from being pulled out. Friction is the resistance of motion when one object rubs against another. The greater the friction, the more force is required to move the object.
2. Increased Surface Area: By driving a nail at an angle, there is a larger amount of the nail's surface area in contact with the drywall. This increased friction provides additional resistance to the force pulling the nail out, making it more secure. The downward force applied by the object's weight is split into two components when a nail is driven at an angle: a component perpendicular to the nail (which would try to pull the nail out of the wall) and a component parallel to the nail (which tries to shear the nail, or slice it). The shear strength of a nail is generally much greater than its pullout strength, so the nail at an angle can hold more weight.
3. Load Transmission: When a nail is hammered in at an angle, it is more effective at transmitting the load into the structure. If a load is applied at the end of a nail driven in straight, it can lever the nail out. However, when the nail is at an angle, the load is transmitted along the nail into the drywall and the structure behind it, creating a stronger anchoring effect. This is called the lever principle. A straight nail can act like a lever with the fulcrum at the wall surface. A small downward force at the end can result in a large force attempting to lever the nail out of the wall. When a nail is driven at an angle, this lever effect is reduced, hence it's more difficult for the nail to be levered out.
All of these principles, come from classical mechanics, part of Newtonian physics, including laws of motion and concepts of force and friction.