A-OX Welding supply
Corporate Headquarters
Sioux Falls, SD

101 North Harlem Avenue
Sioux Falls, SD 57104
(605) 336-1125
Toll Free: (888) 213-2478
Fax: (605) 336-6872

General Manager: Kelly Kleinwolterink
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Services offered:

  • Full service welding & specialty gas provider to the greater Sioux Falls region
  • Wholesale medical gas supplier
  • On-site ISO/IEC 17025:2005 certified Specialty Gas Lab and state-of-the art fill plant
  • Gas cylinder reconditioning and painting
  • Bulk tank installation and setup for industrial, medical, and scientific applications
  • Welding supplies, consumables, and safety equipment
  • Full line of tools:
    Milwaukee, Dewalt, Stanley, Empire, Crescent
  • In-house repair shop
  • On-site consultation available
  • Area-wide delivery available

Our team:

Kelly Kleinwolterink, General manageR

(605) 275-7013
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Mike Lewis, Regional Sales Manager

(605) 275-7031
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Mike Lewis has been with A-OX for 4½ years. He has been in the industry for 21 years, starting in the fill plant, then inside sales, route driver, outside sales, and sales manager. He currently serves as our Regional Sales Manager, working out of our Sioux Falls and Watertown locations, covering sales in South Dakota, Minnesota and Northern Iowa.


Terran Berdgale, Ph.D., Specialty Gases Laboratory Manager

(605) 275-7042
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Over the last few years, Dr. Bergdale has spearheaded the Specialty Gas division of her family owned and operated business, A-OX Welding Supply.  Her education includes a B.S. in Chemistry, an M.S. in Materials Engineering and Science, and a Ph.D. in Chemical and Biological Engineering.  During her graduate studies, Dr. Bergdale taught collegiate level courses, supervised student lab activities, conducted dissertation research, and published peer-reviewed articles.  After her post-doctoral specialty gases training in Chicago, Terran helped start up A-OX’s new specialty gas facility including development and production of all specialty gases and validation of medical gas procedures.  Under her supervision the laboratory gained PurityPlus producer status and ISO/IEC 17025:2005 accreditation.  She most recently became chair of the PurityPlus training committee and serves on the steering committee.  She strives to increase the specialty gas production capabilities of A-OX and enhance overall plant product quality.  Beyond her interests in science and engineering, Terran enjoys traveling, reading, dancing, and rock climbing.