Wedge Inserts


Note: Wedge Inserts are sometimes referred to as Relieving Angle Inserts, Shelf Angle Inserts, Conrete Wedge Inserts or Malleable Iron Wedge Inserts. 

Wedge Insert Catalog Page 

Masonry Anchor Catalog Page

The Wedge Insert is used for connecting relieving angles, also known as shelf angles, to poured concrete or concrete slab. They can also be used to connect any other material to the slab, wherever a bolt protruding from the slab is required.

The Wedge Insert allows for vertical adjustment in the connection providing the erector with a method of securing the relieving angle so it remains completely level despite the inevitable irregularities in the structure. 

Wedge Inserts work with mated Askew Head Bolts. The sloped wedge inside the cavity creates a conection that tighens as weight is applied, so slippage is very minimal.

The System:

The Wedge Insert has three small holes to allow it to be attached to the inside of the concrete form. (See Fig. 1 right, and General Installation Notes) The steel loop around the back of the Wedge Insert provides a way to attach the necessary rebar. (Fig. 2)

Note in the photo (Fig. 3) there is tape covering the face of the Wedge Insert. THIS IS IMPORTANT. While still liquid, the concrete can seep around the face of the Wedge Insert and get in the cavity where the Askew Head Bolt will sit, making it impossible to insert the bolt. The taped face prohibits concrete from entering the cavity.

Once the concrete is poured and fully cured, the form is removed. All that is visible is the taped face of the Wedge Insert. (See General Installation Notes) After removing the tape, inserting the proper length Askew Head Bolt (see chart) will provide a bolt protruding out from the slab. Fig. 4 below shows the angle of the underside of the Askew Head Bolt. The cavity in the Wedge Insert allows for vertical adjustment so the installer can level the Relieving Angle. Typically the Relieving Angle will have horizontal slots to allow for a minimal amount left/right adjustment.

Slotted shims are often used to correct deviations in the concrete slab. The installer / erector should verify what material these shims should be made of. (To see the shims available, Click Here.)

All Wedge Inserts carried by The Steel Supply Company are Hot Dip Galvanized. Hot Dip Galvanized Slotted Shims, Nuts and Washers are also available.


Wedge Insert Askew Head Bolt



wedge inserts