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Ask us about Custom Container sizes.



1. How does the container work?

VakPak65 containers are made of a high quality 309 stainless steel, .002” thick and air-tight, welded on three sides. During heat treating it is used to prevent oxidization from the air outside the container. In addition, the container will work to neutralize entrapped atmosphere at hardening temperatures. The container heats to temperature much faster than the work piece. At elevated temperatures the oxygen inside the container will react with it before it does the work. The container effectually neutralizes the entrapped atmosphere and prevents oxidization.

2. Can you use the container more than once?

No. Once the container reacts with oxygen to neutralize entrapped atmosphere, it cannot do so again.

3. How do I close the container?

For an air-tight seal, insert work piece and fold three times. Use a metal straight edge to press down the last seal. Be careful, as edges are sharp.

4. Is extra hardening/heating time necessary to compensate for the container?

No. The container heats so fast it does not require significant extra heating time. However, because the container neutralizes entrapped atmosphere and protects the work piece, extra time will not harm it. If you are unsure about time in the furnace, you may leave it in longer to ensure great results.

5. Does the container slow down the quench time?

Yes. The container works well with air hardening steels that do not require a fast quench. Simply leave the work in the container in open or moving air. For oil and water quenching steels, it will not cool fast enough to get desired results. In situations like these, an atmosphere furnace is recommended.

6. What is the maximum temperature you can use with the container?

A better question would be “how long will the container last at a certain temperature?” Containers made of 309 stainless are the best the industry has to offer. Many will rate it for use to 2,200° F. It is ok to use this temperature as a guideline, but it will not last long at that temperature. The container could be used for very small pieces of Molybdenum high speed steel involving temperatures of up to 2,200° F and do not require much time in the furnace.

7. How do I prevent the container from sticking to the metal I’m heat treating?

At higher temperatures the container may stick to the work piece. This is usually caused by oil or residue left on the metal surface, over heating or excessive pressure caused by a vacuum. Clean all parts well. Allow some room in the container for the pressure caused by the heat.

8. What about heat treating High Speed Steels (HSS)?

Since HSS hardens at a temperature very close to its melting point, it’s prone to sticking. Make sure the work pieces are clean and leave some air inside the container. Venting a container with a release hole can also help. In order to determine if the container can handle the time in the furnace, test a sample piece of HSS.

9. Temperature in the furnace? Total time in the furnace? Will it work?

There are so many applications for VakPak65 containers there are no certainties. Heat treating is as much of an art as it is a science. Those who benefit from using containers often have much to figure out. In all cases, it is wise to test the container with all special situations. Contact us with your questions or for a free sample by calling us at 508-543-5391 or emailing us at

10. What industries benefit from VakPak65 heat treating containers?

  • Medical device/instrument manufacturers
  • Vehicle manufacturers
  • Aerospace parts manufacturers
  • Defense and arms manufacturers
  • Fabricated metal parts manufacturers
  • Machining and metalworking
  • Sporting goods manufacturers
  • Jewelry makers
  • Knife/weapon makers

11. I own a Sentry Furnace and need replacement parts and accessories. Where do I turn?

We have a select inventory of top-quality OEM parts and accessories made specifically for Sentry Furnaces. Contact us to learn more.