Linear Grinding Improves Special Shape Performance, Tool Life
When a challenging application calls for uniquely shaped tooling, it's important to ensure you don't lose punch strength or life due to an unusual design.
Special shaped punches come with all sorts of challenges. First, there can be punch weakness and easy breakage from having too narrow of a tip or a really long point length. Next, there’s the uneven wear that can result from an uncommon punch shape. Then, there are the increased stripping forces and product adhesion that result from internal features and unusual punch contours. These are the typical challenges of working with unique 2D shapes.
Straight-line grinding adds strength
There are a few ways to manage the challenges of special 2D shapes:
A. Replace tooling often due to breakage and punch wear resulting from unusual punch contours.
B. Use secondary measures such as machining, milling or grinding to deal with the material adhesion that often results from unique shaped punches.
C. Ensure that your uniquely shaped punch is fortified with the best technology available to mitigate breakage, wear and galling, so it retains life and wear resistance, despite its unusual shape.
We recommend option C, and suggest the benefits of straight-line or linear grinding to enhance the performance of uncommonly shaped tooling.
Straight-line or linear grinding is a process that creates an exceptionally smooth punch surface finish. When a punch is linear ground, its grain structure lies in the direction of the stroke of the punch, so its stripping properties are optimized and material adhesion and resistance are minimized.
Linear grinding is especially useful on punches with internal features because of the increased likelihood of adhesion on such designs; however, it can be helpful in other cases as well. When the application necessitates a long or narrow punch tip, straight-line grinding abates punch weakness because it accelerates stripping and lessens the pressure on the tip.
For applications punching softer materials like aluminum or galvanized steel, straight-line grinding decreases material adhesion; and when using premium steel or HSLA, the vertical grain structure of the linear ground punch minimizes the typical gripping force of these substrates.
Linear grinding is not only an effective buffer to the forces impacting your punch — it also shields springs and die components from excess resistance. Thanks to the decreased friction a linear ground punch generates, all elements of your application suffer less wear.
Impax Tooling Solutions® employs straight-line grinding as an automatic process for special 2D shapes with internal features, but it is an optional add-on for other applications, too.
If you think your application might benefit from straight-line grinding or to learn more about this procedure, contact Impax Tooling Solutions®.