Simpson W1 WedgeModel No. W1 Material. 14 Gauge Coating Material. Zinc Galvanized, G90 The W1 is a required component of the Simpson Strong Tie WT wedge form tie that is sold separately. The wedge tie (WT), a form tie that secures concrete forms in place while the concrete is poured, requires a wedge on each end to hold the form boards in place. These wedges are designed for easy installation into and removal from the provided slots. Key Features Designed and