Forms or forming systems usually fall into one of three categories: job built forms built in place; prefabricated job built wood forms which can be reused; patented steel and plywood, all metal, or all wood manufactured forms. Most patented systems rely on a common set of procedures for erection and stripping with minor differences. The following information, consequently, will be found to depart slightly form some details and procedures for any particular system. Most form panels and fillers come in a wide range of widths from one inch up to 24 inches. To make a connection of two forms, either two types of two pieces of the same hardware are required. Some systems have hardware designed for use with all types of connections as well as for accessories. Using a single type of hardware makes for faster work on the job, since workmen aren't confused by numerous different pieces for different connections. A recommended location for erection is at a corner. The first form and corner form should be set, plumbed and braced. The second form should then be connected, the ties inserted and the procedure repeated until a whole side is completed. On larger structures, however, the foundation may be divided into sections that are set, cast and stripped in succession. When a job is broken up into sections or casting is stopped at some point along the wall, bulkheads are used to stop the placement at that location. Where dimensions will not permit the use of standard forms a job built filler can be used to step an odd dimension. It can be built out of plywood and lumber or steel angles to be connected to adjoining forms. Another common use of job built fillers is as replacements for patented forms in locations where pipes, rebars or other materials extend out from the face of the wall. Drilling or cutting of forms is expensive and reduces their usefulness on future work.