Former staff members said they would meet outside the premises on Thursday to cheer the current employees as they leave for the last time.
The company has confirmed it will close the factory by the end of the month, but said it was unable to comment on the final day staff will be working.
Staff were today expected to be given a cast iron plaque and a commemorative booklet celebrating their time at the ironworks ahead of their final shift.
Graham Hickman, who worked at the foundry for 40 years, said: "It's the birthplace of the Industrial Revolution. The Coalbrookdale Foundry has been there 309 years. It's icon is the Iron Bridge, but of course they were involved in making steam boats, railways, locomotives, cookers, boilers anything that could be made in cast iron was usually made at Coalbrookdale first.
"There's a lot of families in the area that have got a connection to the works. Parents, grandparents, great-grandparents – they've worked in the place since it opened. It's a family orientated place. The work ethos has been amazing. You think of a foundry and you think dirty, noisy and hot, but once you're through those doors it gets to you. You come out smelling of sulphur, but you straight away you pick up the atmosphere of working there.
"It is tragic that it will soon be gone."
Graham said that the final details of the celebration outside the foundry were yet to be confirmed, but that they were expecting it to be well attended.
"It's not a celebration of the closing of the foundry," he said. "It's celebrating the history and the loyalty of the people who have worked there.
"Between them, the last 35 employees have done more than 900 years of service for the company.
"I don't think the people making this decision appreciate what the foundry means to the area and it's historical significance."
Aga Rangemaster announced that it would be closing the foundry in May this year.
The company said that the foundry was no longer "economically viable".
The company's factory at Ketley will be kept open, with iron for the Aga ovens assembled there being sourced from other foundries across the UK and the EU which are not part of the Aga Rangemaster group.
Aga Rangemaster was sold to Illinois-based food services giant Middleby Corporation in 2015, in a deal worth about £129 million.