Tri-Ply Circles
Orange Peel Defect in Tri-Ply: Causes and Prevention
That dimpled, citrus-skin texture on a pressed vessel isn’t a finish - it’s a defect. Here is the metallurgy behind it.
What causes it
Coarse grain structure in the steel - large grains deform unevenly during deep drawing, leaving a pebbled surface. Triggered by: wrong annealing, excessive draw ratio, or aged coil.
Which circles are prone
- Over-annealed or improperly annealed lots
- Very deep draws relative to blank diameter
- Coarse-grain heats (check MTC grain size if reported)
Prevention
- Specify fine grain size (ASTM 6 or finer) in your circle spec
- Keep draw ratios conservative
- Trial-press every new lot - 5 circles reveal what certificates can’t
- Reject lots showing peel in trials; it won’t polish out economically
Frequently asked questions
Can orange peel be polished out?
Light cases sometimes; deep orange peel requires removing significant material - usually uneconomical. Prevent, don’t fix.
Have a cookware project in mind?
We manufacture triply cookware and supply tri-ply circles for OEM, private label and distribution. Tell us your specs - we reply with a quote.