We’ve outlined the key features of our production process below. Keep reading to learn the benefits you’ll receive when you choose to do business with us.


One Hit Precison Blank Tank Head

Guaranteed Excellence

Capital Cost: Highest
Tooling: Hardened Inserts For Top & Bottom Dies
Tonnage: Highest
Productivity: Highest
Secondary Operations: None Required
Flexibility: One Die One Part
Best Application: High Volume, Polished & Precision Parts

One-Hit Oversize Tank Head

Only the best

Capital Cost: Medium
Tooling: Less Expensive Top & Bottom Dies
Tonnage: Medium
Productivity: Moderate
Secondary Operations: One Trim After Forming Using Multi Axis Plasma
Flexibility: One Die One Part
Best Application: Medium Volume Parts & Thinner Gages

Dishing-Only Oversize Tank Head

To satisfy your needs

Capital Cost: Lowest
Tooling: Lowest Cost (Top Die Only/No Bottom Die)
Tonnage: Lowest
Productivity: Lowest
Secondary Operations: Two Trims, Knuckle & Polish After Forming
Flexibility: One Die For Different Parts/Knuckle Flanged Separately
Best Application: Low Volume Parts, Custom Shapes, Thickest Gages


  • This process only requires a female die to form the dish.
  • The head material may be pre-polished, and paper protected before air-dishing and the dished area of the head does not need to be re-polished.
  • Air-dished heads do not have internal stresses like spun heads.
  • These heads do not have distortion problems when holes are cut in them.
  • Many different sizes of heads can be made from the same female die.
  • The dished head is trimmed to the required size needed to form the knuckle and straight flange. (using a flanging machine)
  • Bumped heads are formed using male and female radius dies.
  • This process forms a small dished area into the head at a time.
  • Many passes are required over the entire area until a dish is formed to the specified radius.
  • This process is generally used to form thicker heads.
  • This process is not recommended to form thin materials because the dies leave forming marks (“fish scales”) in the head material.
  • After the dishing process the heads must be flanged (using a flanging machine).
  • Dishing and forming together (ie, flanging the ‘skirt’, also known as knuckling) can be performed in sequence on one ALLSTEEL machine using special tooling, thereby reducing secondary operations.
  • The more capital-intensive option, ‘one-hit’ processes allow for higher possible ROIs in the long-run.
  • Full ‘one-hit’, or ‘partial-knuckling’ options available depending on materials.

The ‘One-Hit’ process is as follows;

  • Flat disk (blank) is placed on top of bottom die.
  • Upper die is moved down by press until it contacts blank.
  • Press forms the knuckle radius and the skirt .
  • Press forces top die to clamp material so it cannot slip while being dished.
  • Air under pressure is admitted under the now knuckled part, causing dish to form. Dish depth is monitored by laser sensor.
  • Once desired depth is reached, air pressure is released (Dumped into muffler bank) and then hydraulic pressure is also released (Decompression).
  • Upper die raised by press, finished part kicked out of upper die by means of air pads .