Atlantic Heat Treating Ltd. of Ontario, Canada, contacted Sandvik and raised concerns on the relatively short lifetime of existing SER radiant tubes in its gas-fired furnace, which was failing after approximately 18 months of service. Sandvik then provided replacement tubes manufactured using Kanthal APM extruded material that was sized to work with the existing burner design. The tubes were designed to be a direct replacement for the previous stainless alloy tubes.
 

Atlantic Heat Treating installed the replacement Kanthal APM radiant tubes in April 2010. These tubes are looking at over five years of steady operation versus approximately 18 months with the previous stainless steel tubes. According to Atlantic Heat Treating, the Kanthal APM Tubes have reduced maintenance costs and furnace downtime and increased the throughput of the furnace.
 

<Source: http://www.industrialheating.com/articles/92651-replacement-radiant-tubes-a-success-for-heat-treater>