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Lock-On Vacuum Connector


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Product Description

This solid brass vacuum bag connector locks on to the vacuum bag stem with a strong spring-loaded clip and has a soft O-ring inside which makes a leak-proof connection. All of our vacuum press kits include this lock-on connector. There is no need to purchase this item if you are also ordering a vacuum press kit.

Please click on the Q&A tab above for answers to common questions about this item.

Barb Fitting Option -Pay Attention to This!
The lock-on connector has a 1/4" NPT-female thread on the side where the vacuum supply tubing is attached. Using the drop down options menu above, you can select a barbed fitting that will allow the lock-on connector to work with your vacuum tube size. Select the barb fitting option above that matches the inside diameter of your vacuum tube. For example, if your vacuum supply tube has a 3/8" inside diameter, then you will need the 3/8" barb fitting option above.

Again, the brass fitting option is specific to the vacuum supply tube that you have. It is not related to the attachment fittings shown below.

The locking side of this connector is compatible with the following items:

Vacuum Bags
Bag Stem
Brass Tube
Vacuum Clamp

pg-warning-yellow.jpg WARNING: This product can expose you to chemicals, including lead, which are known to the state of California to cause cancer and birth defects or other reproductive harm. For more information visit

How do I use the lock-on connector with a vinyl vacuum bag from another company?
The existing vacuum stem will most likely have to be removed. Then our flush-mount vacuum stem can be adhered to your vinyl vacuum bag. Our stem kit includes a brass fitting designed to work with the lock-on connector.

How do I use the lock-on connector with a vacuum press made by another company?
You will need to remove any existing fitting on the end of the vacuum tube. Then measure the inside diameter the vacuum tube and select a brass barbed fitting from our options shown above. The barbed fitting is the critical piece that allows the lock-on connector to attach to your vacuum supply tube.

To what thread type does the lock-on connector attach?
The lock-on connector is designed to work with what is often called a "Schrader" thread. This thread is found on all of our vacuum bags and vacuum clamping fittings. It is the same thread found on bicycle and car tires. The external thread size of a Schrader fitting is 0.305 inches outer diameter by 32 threads per inch (TPI), and it has a thread root diameter of 0.302 inches outer diameter.

What is the thread type on the vacuum tube side of the lock-on connector?
The thread on the back end of the fitting is 1/4" NPT.

Other than the lock-on connector, what else do I need to connect my vacuum pump to a vacuum bag?
If you have only a vacuum pump then this lock-on connector is not the right thing to buy. Instead you need to order a vacuum press kit. The connector is included with all of our vacuum press kits. We offer the CRS and EVS vacuum press kits for users that already have a vacuum pump.

Does the lock on connector have a center pin inside?
This unit comes without a pin inside such as those that depress the valve pin on a car tire stem. It is a full-flow design.

Does the vacuum bag have to stay connected to the vacuum press after full vacuum is achieved?
Yes because a perfect seal on a vacuum bag is virtually impossible. Here are some things to consider.

  • Sometimes the bag closure doesn't seat perfectly across the opening.
  • Sometimes the bag stretch a bit after full vacuum is created and will then need a bit of additional vacuum. This happens most often when there is a large project in the bag. You'll hear the vacuum system cycle off (if you have any auto-cycling system) and then turn on again for a few seconds. After that, it may not cycle again for several minutes or even hours.
  • After many uses some bags develop pin holes which can be almost invisible. In those cases, it's best to let the vacuum press keep the bag vacuum under control.

If the vacuum system is disconnected from the bag, you won't know if there is a leak because there is no vacuum gauge on the bag itself. If the bag is connected to a vacuum press system, you can easily see the vacuum level by looking at the gauge on the vacuum press. The vacuum inside the system is the same amount of vacuum inside the bag. If your vacuum press cycles on and off too frequently during a project pressing, you'll know there is a leak and if you can fix it. However if you can't fix the leak, at least the vacuum system will keep manage the vacuum in the bag until the panel is finished.

Product Reviews

  1. Great Products and Good Service

    Review by Tim Bacon

    Really good item. I used it with the bag stem assembly flush mount and my bag was airtight once more! This replaced an older through mount from below, which was always a pain to align and leaked badly.

  2. Very pleased!

    Review by Tim Morris

    I use this fitting on 2 different vacuum pumps and love it. It's quick and easy to attach and release. I have one venturi pump from Joe and another pump to me it's critical that these not leak so the pumps don't run continuously. I've never had a problem with this fitting failing to seal with either system. Very pleased.

  3. Fast Shipping

    Review by Mike Maesner

    Shipping was fast, communication was great and the connector works exactly as I need it to, could not find one locally. This connector combined with Bag stem Assembly is the easiest best way to make the connection to vacuum bag. I use the set up for pressing skis.

  4. Quick and Easy

    Review by Mike Lemer

    The lock on vacuum connector was delivered on time and as advertised. Install on the end of the 3/8" braided vacuum tube it along with the brass fitting for vacuum clamping jigs it worked perfectly, a quick and easy way to connect to the vacuum chamber.

  5. Even Better

    Review by Dwight Fisher

    This one is even better than the one I got from Joe many years ago. Thanks for continuing to improve your already great products.

  6. Extremely Happy

    Review by Mike Mortimer

    I am extremely happy with the bags and fittings supplied. The pricing was good and the delivery updates and timing is first class. I found the info on the website very helpfull and informative Thanks Joe you are supplying a great product I will deal with you in the future.

  7. Great Connector

    Review by Kim Hoogeveen

    This connector works perfect. I'm very satisfied. Thanks!

  8. Review from Okotoks, Alberta

    Review by Matt Lemay

    This is a REALLY handy gizmo. It makes moving from bagging to clamping to chucking a breeze!!! Joe really rocks!!

  9. Review from Long Island, NY

    Review by Brad Herron

    My connector just arrived by post office. It only took 2 days to get here. Looks like a well made piece of brass with clean machining marks and no rough edges. The finger spring clip is strong and you can feel when the vacuum bag stem seats inside. The o-ring inside must be soft so that it makes an airtight connection. It took me a while to understand what this fitting in compatible with but Joe was very patient and helpful answering my questions. Basically... READ THE PRODUCT DESCRIPTION... it tells you what parts the lock on connector will work with.

  10. Review from Sugar Hill, Georgia

    Review by Chris Parks

    This connector is machined to a tight tolerance, so the 1/4" ID brass vacuum clamp fitting mates to it with a tight fit. I bought the lock-on connector with the 1/4" ID barbed end; the connection between the two is air-tight, so it's worth paying a little extra. I ordered all the supplies to make my vacuum frame table from Joe because he has done the work to source the parts needed for my project, saving me time. Plus his customer service is excellent; he ships fast! Ordered one morning, got my stuff the next afternoon.

  11. Excellent Product

    Review by Bijeshj

    I purchased this to make it easy plug and unplug in multiple clamping devices. Joe was very helpful in answering questions and really fast shipping.

  12. Highly recommended

    Review by Randy C

    One of my biggest issues with my connection of my hose to my bag was having to connect the 1/2" tubing to the old barb fitting on the bag and using a hose clamp to secure. Yes...the connection was completely sealed, but I had to hook the hose on before I put my piece in the bag. It was a pain. All my issues were with the hook-up. This quick connector alleviated all of this. I couldn't order it fast enough and even bought a new valve stem kit to replace my old one. I bought a new poly bag and it came with the new valve stem so I can do all my hook-up with this quick connect. It is by far the best thing out there. Highly recommended.

  13. A Great Connection

    Review by Michael A.

    Nice product. I've bought 4 of these to make a manifold system for gluing skateboards in 4 bags at once. This connection system is very rugged and I have never had any leaks with it.

  14. Easy Way To Connect To Vacuum Bag

    Review by Gerard W.

    This connector works very well and I have not yet had any problems making an easy airtight connection. I have another bag from a different company and the tube just gets jammed into a nipple of the bag. Sure enough, it seemed like every time I used it, I ended up snagging the tube on something and then pulled it off the bag. This creates a mad dash back to the bag to re-attach the tube. With this connector, I've had not problems at all. I can pull all day long on the vacuum tube and it will not come of the bag. My shipping cost to Michigan was very affordable. Joe runs a great site and his customer service is impeccable.

  15. Work Perfectly

    Review by Craig Watkins

    I have 6 of these connectors on my vacuum press manifold. I generally run 6 small bags at a time with the manifold and I have a lock on connector at the end of each of the manifold ends. This is a highly quality piece of machined brass that makes a good seal on the stems. There are other options that some companies offer which dont work quite as well. I've had a few of them come loose and nearly ruined my project. I doubt these connectors could pop off accidentally. Even if you tug on it when moderate force, it stayed connected and sealed.

    I should mention that all of my current vacuum press equipment is coming from this website. I just find that the customer support here is second to none and the products are always well made and reliable.

  16. Very satisfied.

    Review by Nathan G.

    No problems. Works as described and shipping was reasonable.

  17. Suprisingly Secure Bag Connector

    Review by Todd Greene

    This is a suprisingly secure bag connector. It definitely feels like a heavy duty product. I had some concerns about how well it would seal against the valve stem but these worries were quickly put to rest when I tried it out on my vacuum bag. The shipping charge was reasonable (though I did have other things with my order) and it only took a couple of days to get here. I'm very satisfied.

  18. Very Smart

    Review by Robert J.

    Excellent item. Very smart "borrowing of an idea" from another industry.

    Great job Joe!

  19. Worked Just as I Had Hoped

    Review by Joel T.

    Great product. Worked just as I had hoped. I will be ordering more parts very soon.

  20. Nice Product

    Review by Mike Joonesburg

    Very nice product. Works very well!

  21. Just What The Doctor Ordered

    Review by Tom Burwick

    Right on the money! This connector is just what the doctor ordered!!! A non-proprietary, heavy duty, and tough as nails bag connector - Finally! Thank you Joe for the outstanding find!

  22. Very Beefy And Rugged

    Review by John Dominoc

    Very well made connector... very beefy and rugged and makes connecting to the bag a simple one handed process.

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