Wood Legs If at all possible, you want to choose a sofa whose back legs are one piece with the frame. This provides the ultimate stability in wooden legged sofas. The front legs then should be double-dowelled, glued and screwed onto the frame. If the legs are only screwed on, they will not be stable within a short period of time because the screws work out. Some manufacturers staple the sofa legs on. This, too, is not a stable choice because the staples will easily work loose when the sofa is moved around.
Metal Legs If you have a more contemporary designed sofa, you may have metal legs to choose from. These also need to be attached firmly to prevent wobbliness. Joints and legs can be welded, riveted, bolted, or screwed on. Welded legs tend to be stronger. Rivets and screws can work out over time, so they will be found mostly in less expensive sofas. Bolts can be a good choice for the sofa legs, especially if self-locking nuts are used because these will not allow the bolt to work out. http://www.alphafurnishings.com/