Shim Production
Use Caution and the Correct Equipment
The Slotted Steel Shim is probably the most basic of all the Construction Product Lines The Steel Supply Company offers. Yet as simple as it is the shim should still be manufactured with accuracy and attention to quality.
Fig. 1
Shown in the illustration (Fig. 1) is a 1/4" thick x 3” wide x 4” long slotted steel shim. It was produced via steel stamping; however, a poorly maintained upper tool caused the steel to buckle at its narrowest point. As is, this shim is unusable and SHOULD BE REJECTED.
Fig. 2
In Fig. 2 the shim is 1/8” x 3” x 8”. Due to its longer finger lengths ( 7” after header) they can easily deflect as shown.
The 1/4” thick shim shown in Fig. 1 will offer enough resistance to compromise the compression of the connection. The 1/8” thick material in Fig. 2 will not, due to its thickness but also the deflection being at the open end of the shim. Regardless, the shim shown in Fig. 2 should ALSO BE REJECTED because the contortion of the fingers with make installation more difficult and time-consuming.
Fig. 3 (Above)
The two Slotted Steel Shims in Fig. 3 show no noticeable deflection. The shim on left is 1/8” thick, on the right, 1/4” thick. Achieving these results requires:
- The punch to allow for adequate clearance with the die
- Consistent punch and die maintenance
- Even pressure delivered by the stripper
- Adequate tonnage and pace on the downstroke
Fig. 4
Figure 4 illustrates shims made via plate fabricating. This method is employed whenever unique dimensions are required. Typical equipment used is High-Definition Plasma, Laser or Water Jet. Thes are known as “Soft Tools” because they can make any size desired and are not locked into exact dimensions like the stamping tools used to make the shims above.
Fig. 5
Fabricated Plate will not deflect but can develop “dross.” This is the slag that can be found on the underside of the cutting line. As shown in Fig. 5 the dross is 0.010” above the shim surface. There are applications where this may not affect performance, such as Wedge Insert / Relieving Angle installation however it adds an unnecessary dimension to the project and can be eliminated with proper attention during the shim manufacturing process.
As with any manufacturing process, quality and production costs have to be balanced. Tolerances, Deflection, Dross and manufacturing speed all play into the decision of which system to employ. The Steel Supply Company has many years of experience and the ability to aid in the design, control the process and deliver an end product that will meet all necessary standards while keeping your project on time and on budget.