The company was founded in October 1927 by Niels Peter Grønkjær, who primarily started with the repair and sale of agricultural machinery. He had 9 children - eight boys and one girl, and it was the youngest son, Svend, who after finishing his apprenticeship and some years at "Vilsgård" on the island of Mors, bought his father's shop in 1940. Soon Niels Peter Grønkjær's old workshop was too cramped for the son and his goals. Therefore, he built a new 170 m2 workshop shortly after buying the company. When Svend lost his wife, Katrine, in 1953, the young girl Astrid became a housekeeper, but soon became much more than that: they got married in 1955 and had three children: Annette, Flemming and Bent.

Over the years, agricultural customers became fewer and was replaced with new industrial customers: Some local, but also customers all across Denmark. Gradually, the company also started dealing with customers in Europe. In 1976, Svend Grønkjær built a brand new and modern 180 m2 workshop in Bredgade 73, Hurup, and operated at this address, until his death in 1986. Astrid Grønkjær then continued her husbands business with the help of Flemming and Bent.

In 1988, the first custom made machine for the butchery industry (ribbons tractor) was developed and put into production at the request of "Vestjydske Slagterier" in Hurup. It was a great success, and soon other custom made machinery was made. Today, these products are exported to several countries.

After a few years of success, the workshop in Bredgade 73 was too small, and in 1992 the building at Industrivej 12 was purchased and furnished into a modern workshop. 

Grønkjær Maskinværksted is a place where good working conditions for the employees are appreciated. GREEN CARS is thus registered as a Level 1 company in the Occupational Safety and Health Administration's customized supervision.