Deep Drawn Aluminum Cylinders

The Problem:

A customer of Tripar’s had been buying a spun deep aluminum cylinder (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 their many manufacturing processes was deep drawing, they reached out to us to see if this cylinder could be produced this way.

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 1500 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 Result:

The net result was that the customer obtained deep drawn parts made to their specifications, along with many advantages:

-Approximately half the price of having it spun.

-Paying less than $8000 tooling.

-Having a much-improved surface finish over spinning, eliminating any need to polish the part to remove spinning marks, saving even more money.

-Having much greater dimensional stability; a significant advantage, given that they need to insert a custom plastic injection molded piece into the open end.

Since then, Tripar has reliably produced over 20,000 of these parts to their customer’s complete satisfaction.

Fabrication of this item may be seen at http://lighting.triparinc.com/2015/05/03/draw-deep-draw/, at time interval 0.22-0.36!

cylinders (1)