The problem
A client was buying deep spun aluminum cylinders (5” diameter, up to 11” long, closed at one end) for approx. $10-$14 each.
Having it spun using the same supplier for years, they were pleased with the product believing that spinning was the most cost effective and the best manufacturing process for this part. The last time they placed a replenishment order, their worst fear was realized; their longstanding supplier had shut down, and without warning!
Having worked with Tripar for many years and knowing that one of our many manufacturing processes was deep drawing, they reached out to us to see if this cylinder could be produced this way.
deep drawing alum cylinders
The solution
Our Engineers analyzed the geometry and material properties of the aluminum required, and determined that making a part with a depth to diameter ratio of over 2:1 would have to be done in 3 draws; a primary drawing operation, followed by two successive redrawing operations, each reducing the diameter and increasing the part’s length to the final requirements.
Having over 1600 dies, over 200 of which are draw and deep draw dies, two were found that could serve for the first two operations without any die modification whatsoever. This allowed us to quote our customer very competitive unit prices at various quantities, with only one die cost; that which was needed for the third and final redraw operation.
The results
The client obtained deep drawn parts made to specs with many advantages:
- Savings nearly 50% per unit vs. spinning
- $8000 one-time tooling costs
- Improved surface finish over spinning, eliminating the need to polish the part to remove spinning marks, saving even more money
- Greater dimensional stability; a significant advantage given the customer’s need to insert a custom plastic injection molded piece into the open end
Since then, Tripar has produced 30,000+ of these parts.
The fabrication of these parts can be seen at time interval 0.22-0.36
