To secure a wooden object to a concrete wall, which of the following types of fasteners is recommended?

Using a masonry nail is the recommended choice for securing a wooden object to a concrete wall due to its design and intended function. Masonry nails are specifically engineered to penetrate hard surfaces such as concrete and brick. They typically have a hardened body that can withstand the density of masonry materials, making them ideal for this type of application.

When driven into the concrete, masonry nails create a secure hold that keeps the wooden object firmly in place. Their tapered design and heavy-duty steel construction allow them to grip the sides of the drilled hole, enhancing stability and strength in the joint.

In contrast, other fastener types would not deliver the same effectiveness when securing materials to concrete. For instance, double-headed nails are typically used for temporary fastening or applications where you may want to remove the nail later without damaging the surrounding material, making them less suited for securing wood to concrete.

Pan head screws are generally utilized for fastening materials together rather than penetrating through dense surfaces like concrete. While hex head screws are strong and can be used for various applications, they are not specifically designed for attaching wood directly to concrete without the use of pre-drilled anchors or plugs. Therefore, the unique attributes of masonry nails make them the best fastener for this particular scenario.