There are two common uses for J bolts, although these bolts can be used in a wide variety of applications. The two most common uses are for anchors in concrete to use to attach walls to the base floor or concrete foundation or to hold batteries in place in vehicles or on equipment.
These are two very different uses for the same type of bolt, which is why there are so many different shapes and sizes of J bolts. Additionally, because of their use, they are often required in custom sizes. Companies that make these bolts to custom sizes need to have experience, expertise and a good understanding of how the bolt will be used in the specific application.
Concrete Anchors
Large sized bolts that have the J shape are typically used as anchors in construction. The curve of the J is inserted to the desired distance in the concrete, ideally with the hook catching the rebar to add to the stability. It is placed into the freshly poured concrete and before it sets.
The threaded end of the bolt is then pointing upwards and straight. Walls can be anchored to this through pre-drilled holes, creating a solid attachment to the floor or foundation. Depending on the type of structure and the applicable building codes, the sizes of these bolts may be stipulated.
Battery Bolts
The smaller diameter and longer J bolts can also be used for holding vehicle batteries in battery boxes. The hook is used to slide under the bottom of the battery box; then a clamp is used at the top to connect the threaded ends of the bolts on both sides.
This holds the battery firmly in place while also making it easy to quickly remove the battery by unscrewing the nuts and removing the clamp or bridge component, allowing the battery to be lifted out for repair or replacement.
