SPT C35 40W CO2 Sealed Laser Tube for Small and K40 Laser Engraving Machine

(You save $55.00 )
Bulk Pricing:

Below are the available bulk discount rates for each individual item when you purchase a certain amount

  • Buy 2 - 3 and get 5% off
  • Buy 4 - 7 and get 7.5% off
  • Buy 8 - 24 and get 10% off
  • Buy 25 or above and get 15% off
(11 reviews)
12.00 (in)
10.00 (in)
48.00 (in)
Current Stock:
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**Free Shipping for Continental US Only**

This high-quality CO2 laser tube is made exclusively for small laser machines. Unlike some low-quality tubes that you may find on sites such as eBay, this tube has a long service life thanks to the catalyst. The output is very stable with low beam divergence. 

Why SPT Laser

Click to know about SPT

Why buy Laser Tubes from LightObject?

1) We're located in USA (Sacramento, California). No U.S. Customs issues

2) We provide great tech support. We are knowledgeable, and we know what we're selling.  Check out our support forum at LightObject.info.  There you can ask us questions, tap into our vast customer network for support and visit our FAQ section as well!

3) Fast turn around time for tube replacement

4) Competitive pricing because we deal directly with the manufacturers

5) High quality and professional packing

6) We test each tube with industry grade laser power meter before it is shipped from California


  • Rated Power: 40W, peak 45W
  • Triggering Voltage: 16-18KV
  • Operating Voltage: 8-9KV
  • Recommend Working Current: 13mA~15mA, max 16mA, peak:20mA
  • Length: 720mm (28.4") +/- 5mm
  • Diameter: 50mm (2")+/- 1mm
  • Water Temperature: 15~25°C(59-77°F)
  • Warranty: 6 months

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


The default shipping method is UPS ground.  Please contact us for the price if faster service is needed.

Additional shipping cost will be charged outside the continental 48 states in the US. Please contact us for shipping cost before placing the order. 

Courtesy reminder

Any damage that happens on the shipment; the buyer must report to us within 3 business days after receiving it. If failed to do so; this will result in the rejection of all claims. Customers must file a report to the carrier and keep all shipping materials handy for inspection. We're not responsible for any internal cracked after receiving, any damage caused during transportation covered by insurance. The buyer is responsible for the shipping cost of a replacement tube if the order date is out of 30 days. Warranty acceptance or denial is subjected to the decision made by the tube manufacturers. Lightobject is not responsible for a denial under any circumstance.

So far so great

This is my first laser tube replacement and I am blown away by the difference between this and the initial cheap Chinese garbage I had initially. I'd recommend anyone getting a K40 just buy this while you're buying your machine and you'll have an excellent backup tube to use as soon as the stock one kills itself. It went in with no issues and the first thing I cut (didn't even end up needing a mirror alignment thank God) was 1/4" MDF. The first tube that came stock with my machine could handle it in 3 passes. This new tube from Light Object cut all the way through in one. Couldn't be happier with my purchase or the professional way it was safely packaged. Thanks, Light Object, you are now my go to for laser parts supply. :)

Review by Cameron on 12/17/2020


  • 5

    Posted by Kyle on Feb 11th 2021

    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. 11/9/2018

  • 5
    Met my expectations

    Posted by Allen on Feb 11th 2021

    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. 11/4/2018