Abstract: The present invention is directed to an improved tool for use in mounting a joist hanger on a header. The tool can be made to accommodate a joist hanger of a single size or can be made so as to be adjusted in size to accommodate joist hangers of different sizes. In the latter cases, a first set of bars can separate from the adjacent, second set of bars to expand the width of the space at the side of which a number of magnets are carried. This allows for greater versatility than when the bars are stationary.

Abstract: A tool having a first member adapted to rest on the upper face of a header to which a joist hanger is to be mounted. A magnetic structure is coupled with the first member for holding a joist hanger in place by magnetic attraction as the first member is supported on the upper margin of the header. Thus, the hanger can be nailed. The magnetic structure includes a second member coupled with the first member and has a pair of opposed flat side faces provided with magnetic structure thereon. Such magnetic structure can be in the form of spaced, permanent magnets extending into holes drilled in the side faces of the second member. The second member can be removably and adjustably coupled to the first member by alignment structure.