Ultimate Vent Blocks


Valve-Less Vacuum Blocks are highly durable inserts designed to connect a vacuum system to a die for active vacuum evacuation of air and gas from the cavity.

  • Use when casting aluminum, zinc or magnesium
  • No moving parts to fail or replace
  • Technical assistance to evaluate parts for applicability of vacuum-assist
  • Technical assistance to design exit runners for optimal evacuation
UVS-Mini2.2503.5401.000Download Download Download
UVS-25002.5005.9402.000Download Download Download
UVS-40003.9385.9402.000Download Download Download
UVS-45004.5665.9402.000Download Download Download
UVS-55005.5125.9402.000Download Download Download
UVS-65006.5005.9402.000Download Download Download
UVS-80008.0006.4402.000Download Download Download

Click on an image below to download a .pdf of the catalog page.

Stationary side


Ejector side


Standard Ultimate Vent Blocks are manufactured from premium H-13, heat treated to 44-46 HRC and stress tempered for long life. Standard Ultimate Vent Block part numbers begin with UVS- (UVS-XXXX).

E-Series Ultimate Vent Blocks are manufactured from pre-hard H-13 and finished with a Melonite surface treatment. E-Series blocks are intended for use zinc or magnesium die casting or for short-run aluminum die casting. E-Series Ultimate Vent Block part numbers end with -E (UVS-XXXX-E).

Copper for greater thermal conductivity

For applications that require the greater thermal conductivity in their casting application Midland offers two options.

Super Chill Blocks


Receive the thermal advantage of copper flow areas combined with the long life of an H-13 holder block. Inserts are replaceable to reduce costs over life of block.

Complete Copper Blocks


Can be manufactured to your custom or Midland standard designs.

Let the experts build your custom Vent blocks!

Let the Valve-Less Vacuum and Vent Block experts design and manufacture your custom chill vents. Our machinery and manufacturing is specifically set up to for efficient manufacturing of chill vents. Every tooth is inspected on our CMM to ensure that your die has the evacuation areas that you have planned for. Email your print or CAD model to quotes@midlandtechnologies.com or, if you require design assistance, please call us at (763) 428-4229.


  • Reduce porosity related scrap
  • Improve part cosmetics
  • Reduce press time to fill quotas
  • Improve part fill



Incorporating vent blocks when first designing die can help to maximize job profitability and minimize potential loss by ensuring proper air and gas evacuation from the start.


  • Higher casting yields
  • Faster job completion with less press time
  • More efficiency in casting process


  • High fallout rates due to porosity or poor fill
  • Downtime while troubleshooting
  • Resources spent troubleshooting


Vent blocks can be highly effective remediation tools when a casting presents unacceptable or undesirable fallout rates due to poor fill or excessive air and gas porosity. Midland Technologies provides the service of reviewing specific casting porosity and fill issues to calculate needed venting area and optimal placement of blocks in relation to the cavity.

  • Ultimate Vent Blocks are installed into a pocket cut directly into the die set or mounted to the outside of the die using support blocks.
  • Locating pucks are utilized to ensure critical alignment between the stationary and moveable sides of the Ultimate Vent Block
  • A runner system is cut from the cavity insert to the Ultimate Vent Block providing a highly efficient means for evacuation of air and gas from the cavity. Midland can design your exit runner scheme when you purchase Midland Ultimate Vent Blocks and provide a 2D layout of your die.


Correct installation is critical to proper function

Ensure parting line of blocks is flush with, or .001 – .002 proud to cavity inserts

Blocks inserted at least 4.50″ from the edge of the mold base

Inlet of blocks should be flush to the die cavity insert and mate evenly in closed condition

Correctly machine pockets to ensure no shift in locating key

Use vertical mounting holes when running with water

Manage velocity with properly designed exit runners

Excessive velocity in metal exiting the cavity can lead to several failure points when using Ultimate Vent Blocks. To achieve the best possible results, we recommend managing velocity of metal as it exits the cavity to help prevent solder, flash, spitting or runner washout.

Midland Technologies can supply you with a recommended exit runner design when Midland Valve-Less Blocks are purchased!