This will see the creation of 43 new jobs in the next 12 months.
The expansion is due to major growth largely focused on new export links to the UK market.
The firm now has four sales depots across Great Britain.
Steeltech is located at the old Coca Cola site at Galway Road in Tuam and manufactures garden sheds, steel sheds and garages.
OPW Minister and Galway East TD Sean Canney says Tuam has a great history of attracting business to the town with other firms establishing bases such as JFC, Valeo and Transition Optical.
He says it’s perfectly positioned to attract further investment due to the development of the new motorway.
Jobs Minister and Milltown native Mary Mitchell O Connor is at the company’s head office in the town this lunchtime for the announcement.
She agrees Tuam has a lot to offer.
Steeltech Sheds CEO Sean Brett says the additional 43 jobs will bring the workforce to 170 by year end.