L-type anchor bolts have a bend at one end to grab onto the concrete or masonry structure. These type of anchor bolts are normally cast-in-place---meaning they are inserted into the concrete as soon as it is poured. The concrete cures, and securing retains the bolts in place.
Concrete anchor bolts are used in new construction to secure a structure's walls to concrete slabs and foundation walls, to fasten steel columns to concrete piers and to anchor machinery to concrete pads.
L-bolts are set into fresh concrete. This type of anchor bolt is shaped like the letter L, so it can not be pulled out of the concrete after the concrete has hardened.
L-bolt anchoring bolts come in many different lengths, the most common are 6, 8, and 12 inches long. These bolts are threaded at the top, for about two inches, and the rest of the bolt is smooth. We use this type of concrete anchor bolt on almost all the new concrete slabs we pour. As soon as the slab is poured we go back and sink the anchor bolt down into the concrete, leaving the threaded portion sticking up high enough to secure the walls with a washer and nut.