Concrete Anchors or Masonry Anchors are typically made of metal and aid in anchoring objects to a floor or walls made of concrete or masonry. Walls can be made with hollow masonry blocks or be made with solid concrete or filled masonry. Selecting the proper anchor requires knowing the weight of the object being fastened to the surface. Generally, two types of loads are considered (shear and tensile), but sometimes you need to know if the object will exert static, dynamic, or impact stresses. Static stresses are exerted when the object does not move such as with a breaker box hung on a wall. Dynamic stresses are exerted when the stress levels change as in vibrating such as with a circular saw anchored to the floor; use of the saw causes vibrations to be exerted through the anchor and into the floor. Impact stresses occur when loads change suddenly as with a box tossed onto a shelf anchored to the wall.
Masonry anchors and concrete anchors are rated with tensile and shear strengths. You should ensure you purchase masonry and concrete fasteners designed to support the required loads. You should also ensure the concrete or masonry are strong enough to function as a stable anchoring surface. Crumbling masonry and concrete will reduce the effectiveness of the anchor.