This according to Joyce Hasselman Nigbor, long time researcher of the Hasselman Family and the publisher of the pamphlet Titled Hasselman Genealogy,1972.

There are at least two Hasselman Coat of Arms, but it is not known if either could be used by this branch of the family.  A man who sold "family crests" at the Stuttgart, Germany (Patch Barracks) Bazaar in 1974, said that the name Hasselman may originally have been Dutch.  People from Holland were at one time imported into Germany to drain the swampy tidal areas along the coast as they had had experience in doing this in their own country.

A Historiography put out in 1972 by Halberts states, "the surname Hasselman appears to be locational in origin, and is believed to be associated with the Germans, Dutch and English meaning 'one who came from Hassel (place where hazel trees grew).' "
Elsie Gunther commented that "quite a coincidence is that around the Hasselman house and farm yard (Peru Township, LaSalle Co.) area, the wild kind of Hazel nut trees (or bush as my dad Albert called them) once grew abundantly, and required a lot of hard work to grub them out to prepare the land for pasture and farming."
 

This according to Jerry Haszler, creator of the web site.

A web site was found created by an organization called 'Hall of Names International Inc." which states they have 1 million names researched over a 25 year span and 800,000 family name Coat of Arms.  The surname Hasselman has been researched by this organization and claims to have their Coat of Arms and Family Origins and History.  Although this information has not yet been sent for their brief excerpt states as follows;
"The Origin of Hasselman - The very first record of the family name HASSELMAN was found in Derbyshire, which is located in England.  The HASSELMAN family traces their ancestral roots back to Anglo Saxon origin before the year 1100.  From here they branched and migrated, gaining prosperity as a notable family of England and later other countries.