Sandra, a couple of observations:
1. The apprentice record Moira referred to indicates that Jonathon did not purchase his freedom at the end of his apprenticeship. One common reason for that would be that he just continued working for his master.
2. Do you only have Thomas in the 1841 census? If so do not necessarily assume he was a son of Jonathon and Mary. Could he have been the Thomas who died age 76 in 1883 in Sheffield, who was born in Kegworth, Notts accordung to the 1881 census?
Dave

Thanks, Dave. I have no idea how apprentices worked then or about buying freedom, so that is interesting. Buying freedom was done if one no longer wished to work in the trade? Any idea what that cost?

I only have Thomas in the 1841 census (not sure about the 1851 census) but he is listed there as a member of the household at Bright Street, Sheffield, along with Johnathan and Mary.

I have no reason to believe that he is not the Thomas who died age 76 in 1883 in Sheffield, who was born in Kegworth, Notts accordung to the 1881 census! Is there a way to trace him to the family any other way for more certainty?

Thanks again.

Sandy,
Gaining freedom was buying a personal trade mark from the Company of Cutlers. Basically he had finished his apprenticeship and was striking out on his own. Some simply decided not to do that and just carry on working as an employee. It looks like Jonathon did that because the record does not indicate that he became a freeman.
The cost will be easy to find by Google.
My comment about the 1841 census was that there is no indication of relationship in that census. If he was born out of county he may have been a nephew for instance. That may explain why his baptism has not turned up. The best way to check would be to find him in other censuses, which will give his place of birth.
Dave