Steadfast Engineering, which supplies bolts and fasteners to the oil, gas and water industries has been sold.
The company, which has operations in Manchester and Aberdeen has been acquired by Midlands-based Marla Tube Fittings.
Steadfast delivers niche bolting products and engineering capability to firms including Shell.
The business achieved a turnover of £17.9m in 2015, up from £14.5m the previous year.
Steadfast currently employs more than 90 staff.
Its Aberdeen operation services the North Sea inspection, repair and maintenance market.
The deal will see the existing founders Ken and Andrea Sharp exit the business.
Andrea Sharp, co-founder of Steadfast, said: “Ken and I are incredibly proud of the business we have built over the past 40 years and believe that the business will continue to grow from strength to strength under Marla’s ownership.”