Among them will be Tanilba Bay's Aubrey Brooks, a third generation BHP worker who clocked up 38 years at the steel giant, following in the footsteps of his father, Jim Brooks, and grandfather, James Massie, who started working at BHP in 1915 and worked there through the two wars and the Depression.

Aub's brother Barry also worked at the Newcastle steelworks.

"This is a wonderful occasion and a very significant milestone for the thousands of people who have been through the gates of the old site," said Mr Brooks, who as the BHP Newcastle history researcher has become the symbol and advocate for all BHP workers since its closure on September 30, 1999.

"I am looking forward to getting re-acquainted with many former workers and honour the 400-plus former workers who are no longer with us."

Mr Brooks said the 20-year anniversary - the first reunion in four years - would be particularly special for the Men and Women of Steel.

"Prior to 2015 the reunions were conducted annually [under the banner of the Newcastle Industrial Heritage Association]. It was decided after 2015 to stop holding the reunions which did not please everyone," he said.

"Then about two years ago I began receiving correspondence from former workers eager for a 20-year celebration.

"For many former workers, BHP was more than just a job it was an integral part of their lives. When people began contacting me for a 20-year reunion I thought to myself this is too important to let go. I know many of these people, like me, enjoy getting together to reminisce."

The reunion will be held at the Carrington Bowling Club on Saturday from 12.30pm.

This will be followed on Sunday (September 29) and Monday (September 30) from 10am to 3pm with tours of the Muster Point and Deprat's Cottage in Mayfield.

The Hunter United Credit Union and the Phoenix Health Fund will present two cheques to the value of $2000 each to the Hunter Prostate Cancer Alliance. Contact Aub on 0407 452 714.