The Adjustable Bolt-Box Precast Form System shown in the pictures consists of a bolt-together outer jacket, collapsible bolt-together Inner Core, top and bottom ties and Corner Keys. This versatile system, with collapsible core and adjustable jacket panels, is economical and allows for many different square and rectangular box form designs, while giving the producer the ability to adjust the wall thickness and the length and width of the element.

The bolt-together outer jacket has bolt holes on each end that allow adjustments in the wall thickness to be made. For example, if the minimum wall thickness is 4″, the wall thickness may be increased in 2″ increments up to 10″. Furthermore, Jacket Panels may be bolted together to make different length panels.

Bolt-Together Outer Jacket Wall Panels are constructed with 1/4″ plate skins with 1/2″ x 8″ plate ribs and all holes are 13/16″.

Bolt Together Collapsible Inner Core Panels are all one height, consisting of varying lengths required for different rectangular shapes and interconnected by Corner Keys which allow the core panels to collapse inward so that product may be extracted from above.

Collapsible Core Panels are constructed with 1/4″ plate skins, C8 x 13.75 channel horizontal ribs reinforced with C6 x 10.5 vertical stiffeners.

Core Panel Collapsing Corner Key – A heavy duty ½” Slotted key that is pulled up to allow the Core Panels to collapse inward.


Core Panel and Jacket Panel Extensions — Allow for adjusting the box size in very small increments without having to order completely new Core and Jacket Panels.

Adjustable Pallets and Headers — Adjustable Pallets and Headers may be utilized with this form system.

Box Culvert Haunches — The form system can be setup to make box culverts.

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