Steel Manufacturing Blog: Keeping it Steel

Steel Wedge Manufacturing

Posted on Mon, Feb 25, 2019 @ 12:03 PM

The Steel Supply Company manufactures steel wedges both as standard stock sizes and made to order per customer's specifications. A wide range of tools and manufacturing processes are employed and, as with any process like this, costs are kept to the minimum that will allow a high-quality finished part. Nonetheless customers are frequently surprised at the difficulty of wedge manufacturing.

There are several ways to approach manufacturing a steel wedge. The first, and most common for small run and unique sizes is to machine the wedge down from plate or bar stock. Steel-Wedge---Machined-xThis is done using any combination of horizontal band saws, horizontal and vertical milling machines, and horizontal grinders. The steel wedge is often finished on a belt or drum sander. The advantage to this method is there is virtually no tooling cost. The downside is twofold. It is a destructive manufacturing process in that a significant part of an existing piece, the plate of bar stock, is removed and becomes scrap. It also is a process that never gains in efficiency. Every wedge is machined one piece at a time and as a result the cost per copy gains no benefit from volume or efficiency.

A made to order steel wedge, that is a size that will not be done again, rarely has the volume to justify making the tooling to produce it from scratch. To produce the tooling to automate the process usually involves a size we will put in our catalog, keep in stock and sell in random quantities on an ongoing basis. The cumulative volume allows the cost of the machinery to be amortized, typically achieved in 12 to 24 months. The manufacturing process employed is most often drop forging, although sand cast mold can be employed when the finished product can be more malleable.

Drop Forging is the process by which steel blanks are heated to extreme temperatures, between 2,200° and 2,500° F, and are flexible enough to be formed as they are hammered into shape. Drop-Forged-Tapered-WedgeOften the work-piece is re-heated as the shaping continues. This process adds several advantages. First there is no drop or scrap. No time is wasted removing stock. The process cuts manufacturing time dramatically and reduces cost. As well, each time the steel is heated it burns off impurities and each time it is hammered the grain is drawn finer. Both of these characteristics make the wedge stronger.

Even with these advantages the is real no "Mass Production" of steel wedges. The time involved, manpower, and tooling costs all contribute to a product that is difficult to manufacture efficiently.

 

Tags: Wedges, Steel Wedges, Steel Wedges Made To Order

Plastic and Korolath® - Machining and Shaping Wedge Shims

Posted on Sun, Feb 17, 2019 @ 03:52 PM

When shims are required to be angled, wedge shaped, or anything other than flat squares and rectangles, specific steps have to be taken to offset the difficulty these angles create.

The first decision in manufacturing a made to order shim is material. Steel or Plastic Shims, and all the sub-materials that could be involved? Typically, our made to order plastic shims are HDPE, High Density Polyethylene or HIPS, High Impact Polystyrene. Steel shims and steel wedges are usually Grade 50 carbon steel or 303/304 stainless. When deciding on material of course the function and demands of the application are the dominant criteria, but if possible take into consideration plastic costs less and is much easier to machine than steel, hence will significantly lower cost and shorten delivery time of the finished product.

Slotted-Wedge-Shim-300-x-258The Slotted Wedge Shim shown in Fig. 1 illustrates the steps required to manufacture this item. Unless a wedge is poured, using an injection mold or sand cast mold, it will be machined from flat stock. The shim in Fig. 1 is 4-1/2" x 4-1/2" x 9/16" thick. The flat stock starts out as sheets 48" x 96" x 5/8" thick. It is first cut into squares, 4-1/2" x 4-1/2". The next step, the angle, is the most difficult and critical. It can be saw cut or milled. The difficulty lies in securing the part.

If saw cut, the stock is cut standing upright with the saw blade cutting an angle from one corner diagonally across to the other. The result is two angled pieces. Allowing for a 1/16" wide cut the remaining wedges are 9/16" at the thick end. Sounds simple but the vice, tool and clamps that hold a piece like this in place confront a dimension not present if the wedge is being made of steel. Even with a compression strength of between 7,000 psi and 12,000 psi the plastic is considerably softer than steel and subject to movement and flexibility. As the blade passes through the work-piece is vibrating and can move off line or break loose from its fixture.

If the piece is being milled it will lay flat and either a vertical or horizontal mill will remove the unwanted material. In this case only one wedge shim will be produced. The remainder of the material will be milled away. The same problem exists as with saw cutting. It is difficult to secure the piece well enough to hold it in the correct position for the full milling process. While more difficult to mill, steel shims can be fixed in place using magnetic vises. Plastic must be held exclusively by clamps.

Once the wedge angle is fabricated the slot is relatively easy. At 13/16" wide it is the most common shot width so The Steel Supply Company own stamping punches that enable the slot to be formed in one down-stroke. These are the same punches used to make our slotted steel shims.

 

Tags: Shims, Wedges, Plastic Shims