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

Retail Price: $195.00
Price: $165.00
64 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. An easy way to connect the wire is clamping the pin with an alligator clip.

 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 )

Works Perfect

Review by Brandon Rowe on 6/10/2013

We run a Full Spectrum Laser, 40 watt and got this for the replacement tube. Fast and easy hookup. Had to adjust my mirrors and workers perfect.

K40 Replacement

Review by John on 4/20/2015

Carefully packed and delivered in perfect working order. Very steady power when the water system is working correctly: Inlet at the output mirror (-Lead) and outlet at the rear mirror (+Lead). 1.6LPH (Pump rated at 6000LPH) is enough to self purge the bubbles and gives a 1C input to output differential at 70% power = 11.5mA... Marco indicated 16mA as the maximum continuous current for this tube. I used Digikey ED1189-ND socket pins to connect the power leads: Plug onto the laser tube pins and solder to the socket solder tail. Connecting the hoses was a challenge until I made a 3/8" diameter mandrel made into a cone the same size and shape as the water inlet. Soak the hose in hot water so you can shove it 1/2 inch up the mandrel and then use freeze spray to lock it in shape. In a hurry, pull the hose off the mandrel and shove it onto the laser before it warms up at which point it shrinks onto the water inlet. VERY happy with this tube.

Works great

Review by T on 1/8/2016

I purchased this to replace the stock tube that came with my K40 laser I purchased off of eBay. It shipped the same day I placed my order and was carefully packaged. It is slightly longer than the stock tube, but fits great with no modifications necessary. It works great so far and seems to have more power than my laser ever did before, even when it was new. I will definitely be back here to purchase again when I need another tube.

Works great

Review by Charles on 6/27/2017

I purchased this to replace the stock tube that came with my K40 laser. It shipped the same day I placed my order and was packaged carefully . It is a little longer than the stock tube, So far it appears to have more power than my laser ever did before. I will definitely purchase it again when I need another tube.

Works perfectly

Review by Mike on 7/20/2017

Tube is as described, replaced my old fading tube and this is working just like it was when the machine was new. This is for a Full Spectrum Laser 5th Generation Machine.

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