June 2, 2008
Editor's Note: This is the second part of a two-part article about reading progressive-die strips. Part I, which appeared in the May issue, covered the causes of pilot hole distortion and mismatched cuts. Hard marks, otherwise known as coin marks, occur when metal is severely squeezed between two...
June 1, 2008
Looking at the results of a process—in this case, the strip produced in the die—certainly can lead to good data indicating the root cause of a problem. This Part II of a two-part series discusses hard marks, poor die design, and coil-related problems.
May 1, 2008
Looking at the results of a process—in this case, the strip produced in the die—certainly can lead to good data indicating the root cause of a problem. Distorted, elongated pilot holes, mismatched cuts are common defects. Distorted pilot holes can be the result of a poor carrier design. An improperly set up feed release can cause misfeeds, pilot hole elongation, and bent, broken, or galled pilots, as well as poor part location and gauging.
April 29, 2008
Many factors influence tool steel selection. Part Iof this article focused on selecting the right cutting clearance. Part II discusses properties to look for in tool steel and the importance of heat treating, preparation for production, coatings, lubricants, and the press on which the tool...
March 15, 2008
Extrusion is the process in which a continuous radial stretch flange is created by expanding a hole. Of all of the factors controlling the success of an extruding operation, material type and its mechanical properties are the most influential. Materials exhibiting good stretch capability and stretch distribution characteristics are best suited for extruding.
February 12, 2008
Selecting the right cutting clearance and tool for an application is among the challenges stampers face. Material properties and other factors influence this decision. Following some basic guidelines presented in this article can help you select or design the best tool for your needs.
December 11, 2007
Part XVI of this series wrapped up the discussion of bending in stamping operations. This article focuses on drawing. What Is Drawing? Drawing is a metal forming process in which a product is made by controlling sheet metal flow into a cavity and over a punch. The process of deep drawing means...
November 6, 2007
Slivers are the result of the aluminum interfacing with the cutting sections or punches. To reduce the production of slivers the severity of friction at the point where the two surfaces interface must be reduced. The general rule for cutting materials is the softer the metal the smaller the cutting clearance.
October 9, 2007
Part XV of this series described several bending methods—wipe, coin, relief, pivot, and V. It also discussed springback and how to compensate for it when using these methods. This article focuses on other bending processes. Keep in mind that the key to success is to design the bending process so...
October 9, 2007
There is no best tool steel type, coating, or way of keeping the punches from breaking. The best solution for each of these problems can be found by collecting specific data with respect to why each of the problems occurs
August 8, 2007
Part II of this series presented a basic overview of metal forming operations, such as bending, flanging, drawing, ironing, coining, curling, hemming, and embossing. This and future installments discuss these operations in more detail. We will look at factors controlling the success of each...