Process Date: July 1999

This application required a 0.01" thick stainless steel part to be lap welded without penetrating the underlying metal. Excellent results were achieved using a Synrad model 60-2, 240 watt CO₂ laser.

A high quality laser beam may be focused to a very small point, providing enough power density to enable keyhole welding. Keyhole welding is a method of laser welding in which the laser beam creates a vapor cavity in the part to be welded, which is then filled in with liquid metal. This process allows welding to occur with minimal heat input, resulting in low thermal distortion, which makes it ideal for welding thin sections and heat sensitive parts.

To accomplish this application, the laser beam was used in continuous wave mode. However, pulsed mode can be used for thinner materials or precision welding.

The selection of shielding gas and the amount of shielding protection required for a welding application is dependent on both the material and the required post-weld mechanical properties of the part. As in any welding setup – particularly laser welding – the two surfaces to be joined must be aligned soundly to ensure a proper seam. This is the case for lap and especially butt configurations.


0.01"- thick 304 stainless steel part, welded around its circumference with Synrad’s 240W CO₂ Laser

Laser weld on stainless steel part magnified 30 times