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SPT 35W CO2 Sealed Laser Tube for Small K40 Laser Engraving Machine

Retail Price: $195.00
Price: $165.00
47 units available
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 This high-quality CO2 laser tube is made exclusively for the small K40 laser machine. Unlike other low-quality tubes that you may find on sites such as eBay, this tube is made by a reputable company. The output is very stable with low beam divergence. The length of the tube is 720mm (+/-5mm) or 28.5" .

Shipped from California.  All tubes are tested with power meter prior to shipping. Do not overdrive the current or the life span of the laser tube will be shortened.


    • Power: Rated 35W (it can output more than 40W at 16mA)
    • Triggering Voltage: 18KV
    • Operating Voltage: 15KV
    • Current: 13mA~15mA 
    • Length: 720mm (28.5") +/- 10mm
    • Diameter: 50mm (2")
    • Water Cooling required. 18~24'C(64-75F)
    • Warranty: 6 months
    • NOTE: Wires in the picture are not included.

 Recommend using ID 8mm water tube.

Why buy a laser tube from us?

1) We're located in USA (Sacramento, California). No US Custom issue

2) We provide great tech support. We are knowledgeable, and we know what we're selling

3) Fast turn around time for tube replacement

4) Competitive pricing because we deal directly with the manufacturers

5) High quality and great packing

 (Note: pictures are showing a test for a 60W laser tube)



Note: 600W water chiller with a compressor (refrigerant) is highly recommended for cooling. Recommend LightObject  LO-600W chiller.


Shipping: The default shipping method is UPS ground for all laser tube orders.  Please contact us for the price if faster service is needed.

Get a quote on shipping fee: add all items to the shopping cart. Click the "cart icon" on the upper right corner of the page. Lastly, enter your state and zip code, our shipping estimator will show the shipping fee along with the available shipping method.

Multiple Item Orders -  please add each item to the cart and then click on the "Shipping Estimator" to get the shipping cost.


Note: International buyers are responsible for duty tax.


Courtesy reminder: Any damage that happens during shipping, the buyer must report to us within 3 business days after receiving it. Failing to do so will result in the rejection of all claims. Customers must file a report to the Carrier and keep all shipping materials handy for inspection. The buyer is responsible for the shipping cost of a replacement tube after 30 days of receiving the product.


Average rating 10 out of 10 ( based on 15 reviews )

Great tube

Review by Jeremy on 12/15/2018

Works great, well packaged! I am very happy, will buy again when needed!!


Review by Kyle on 11/9/2018

Bought this to replace my tube on the K40 and it was extremely easy to install. Perfect fit and after an alignment with new SI mirrors I’m back up and running. Fast shipping and tube was packaged extremely well. Awesome product and great company.

Met my expectations

Review by Allen on 11/4/2018

I built my own BuildLog laser in 2013 and it finally died. I chose this tube as a replacement and I am glad I did. It is a quality device, actually better in person than the pictures (as of time of this review) indicate. The output head is an anodized aluminum, the water tubing is of good quality silicon (so it looks anyway) and the high voltage lead is -very- well supported and attached. I didn't care for the ground wire (too short for my application), so I discarded it but I don't count that against the tube as I was going to replace whatever came on it anyway. The glass tube was packaged quite well and I think it could easily withstand shipping issues with no issues. I purchased my other laser components here from LightObject and I will continue to do so because the support and quality of components is excellent.

Tube saved a large job

Review by Doug on 10/24/2018

The original tube just quit in the middle of a large job. Had ordered this tube to have just in case a week ago. Seems to cut much better at lower power.

Drop-in replacement for Chinese laser, good support

Review by Stuart on 10/15/2018

This was my first tube replacement. I received excellent support before and after the purchase of the tube.The tube was tested, dated, and the results were documented. The tube was very well packaged and arrive unscathed. There was a tiny bit of water in the tube which indicates recent testing. Metal water inlets seems to be better design than the all-glass. Tube is "pre-wired", so I had to "butt splice" the high-voltage and return wires. So far it's working great! The only VERY minor feedback is that it would have been nice to get a little more documentation on the best practice for making the wiring splices, but there are lots of resources on the Internet for that.

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