50W tube into K40

Is it worth buying a 50W VEVOR tube into K40?
Trigger voltages are the same.
I could fully turn it up to max 20mA without burning out tube.

Has anyone tried it long term?

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That tube won’t fit in a K40 case without an extension. A metal extension that is electrically connected to the case is important for safety.

There have been plenty of folks here who have at least talked about doing the upgrade. Search results for '50w k40 ' - Maker Forums definitely covers more than this case, but I think there are plenty of relevant results in there worth glancing through.

Whether it’s worth it or not depends on the work you are doing, I suppose.

You might describe what work you plan to do and what, if any, modifications you have already made to your laser. For instance, in many cases, you won’t get a lot of additional benefit from the extra power if you haven’t added air assist.


I did search the forum, but didn’t find similar setup.
My K40 arrived with broken tube.

The goal is to extend the life to +2000hrs, branded/SPT is a bit expensive for me, so I was thinking buying a bigger (50W) cheap tube and underpower it to max 20mA.
Lasts longer and gives out real 40W. So win-win.

Yeah cutting a hole is not a problem.


Sorry to hear about the broken tube! I want to be clear that the link to search wasn’t passive aggressive, just intended to help. :relaxed: Found one for you:

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Yeah I read that, but he wrote:

SPT 850mm CO2 Sealed Laser Tube (40W) from light object
actual 40W tube vs the 35W tube the K40s actually come wit
The new tube is a true forty watt and needed the extra space provided by the extension tube. I was going to replace it with the OEM tube to avoid the extra hassle but it was not much more money. I’m glad I did, the extra power really is nice.

So it still counts as 40W, the 50W chinese still cheaper than a branded 40W.
I would you know a good EU supplier for a branded 40W tube at <150eur?
SPT starts at 200eur with shipping :frowning: (half the price of K40)


Depends on your use case as well. A higher powered laser does has a wider beam so it will affect engraving resolution. If you just do cutting and need the power to get thru faster or thru thicker materials then it’s a good upgrade.



I’m looking at heading down the same path as yourself. Wondering if you ended up putting in the 50W and if so, did you notice a difference with engraving resolution, or have any issues with the stock power supply?