What distinguishes a boltable clip from a weldable clip? Let’s delve into the specifics. 

A boltable clip comprises a cam and a clip. The cam, positioned at the top, interacts with the clip. The clip, designed with a rubber nose to counteract any bow-wave effect or uplift forces within the rail system, also features edges for active contact. As the nut secures onto the cam, it actively presses the clip against the rail’s toe, establishing a secure connection. Lateral adjustment occurs through the clip’s longitudinal movement, aligning it with the rail’s toe to accommodate required alignments. Subsequently, the clip necessitates secure attachment to either a plate or a structural element using a bolt from beneath and a nut from the top. 

On the other hand, a weldable clip consists of a weldable lower component and an upper component. The upper part sits atop the weldable lower component, held together by a screw and nut. Similar to the boltable clip, the upper component allows lateral adjustment in the longitudinal direction to conform to necessary rail alignments. Meanwhile, the lower component is welded onto the structure, either pre-fabricated on a plate or a structural girder. This upper component also integrates a rubber nose for handling minor forces due to the bow-wave effect and facilitates active contact via a specifically designed bolt and bolt cavity. The torqueing of the bolt prompts a slight angular shift, compelling the clip against the rail’s toe for secure fastening. Additionally, these clips can be installed using a pneumatic wrench. 

The pivotal distinction lies in the installation process. Weldable clips, due to their pre-fabricated lower components on plates or girders, facilitate top-down installation. This negates the need to access the underside of the girder or plate to secure the bolt, streamlining the installation process significantly. Examples include plates pre-equipped with lower components, fabricated and galvanized by the supplier, and girders with pre-welded lower components, supplied to the site for straightforward installation. 

In essence, this differentiation underscores the contrasting installation methods and efficiency between weldable and boltable clips.