Portland Works was the first factory where cutlery craftsmen worked together under one roof
The first place in the world to produce stainless steel cutlery could be lost forever if £500,000 cannot be raised by the end of January.
Portland Works was built in the 1870s near Bramall Lane, south of Sheffield city centre, and the Grade II*-listed building is now a workspace for specialist Sheffield trades.
The Portland Works Campaign (PWC) group said if £500,000 could not be raised to buy the building by 31 January, it was "only a matter of time" before it became flats and offices - a fate it narrowly escaped in 2009.
In total, 35 people work at Portland Works - artisans and crafts workers, including silver platers and engravers, cabinet makers, a specialist knife maker, artists and musicians. The campaign group wants it to become "a centre of excellence in Sheffield-type crafts".
In six months £130,000 has been raised from the sale of shares, ranging in price from £100 to £20,000. The shares are for sale until the end of January.
The Architectural Heritage Fund will provide a loan of £300,000, which leaves a £70,000 shortfall. The next move the PWC plans is a scheme to ask local businesses to invest in the building and become "Portland Patrons".
In August 1913 Harry Brearley created a steel alloy of chromium and carbon, which he found resisted acid attack.
His employer, Firth Brown Steels, was not interested in the armament potential of what Brearley called "rustless steel" so he suggested it was used for cutlery, which until that point had been made of carbon steel which was liable to rust, or plated with nickel or silver, which eventually wore through to the base alloy.
Brearley's new alloy arguably was the first batch of what became known as stainless steel.
A structural survey showed surprisingly little wrong with the fabric of the building
Stuart Mitchell forges specialist handmade knives, swords and daggers in an upstairs workshop. The family business moved there in 1980 from the nearby Stag Works.
"In 1913 Portland Works was the first place in the world to produce stainless steel. It is very important, not only for Sheffield but for the whole world."
Mr Mitchell said the building was "revolutionary" in its day for the way that cutlery craftsmen worked together under one roof for the first time.
Many of the Portland Works shareholders have a personal connection with Sheffield, while others were inspired to invest after visiting the building or hearing about its uncertain future.
Martin Winterton, from Skipton in North Yorkshire, is one of the shareholders. His great-great-great-grandfather William Willey worked in the Sheffield cutlery industry in 1790.
"Portland Works is so involved with the whole culture of Sheffield," said Mr Winterton. "If this building isn't preserved people will suddenly turn round and realise they haven't got it any more - everybody will wring their hands and say, 'if only'."
Shareholder Rob Marston said his interest in Sheffield's industrial history led him to invest in Portland Works. Rather than wanting to see a financial return on his investment, he views the shares as a way to preserve an important place.
"I liked the idea of keeping it working, not preserving it in aspic as somewhere you'd only visit on heritage open days," he said.
"It's living in the real world - they're finding new ways of using the building. It could be an exemplar, rolled out in other industrial areas of the city."
If the £500,000 target cannot be reached by 31 January, the PWC said shareholders' money would be returned.
Derek Morton, chair of the PWC, said for many tenants a move would not be financially viable.
"Half would survive a move but we'd lose something special. Portland Works has a very strong skill set which is special to Sheffield - it's the nature of the businesses."
PWC said it hoped to complete the purchase of the building in early to mid-2012.
Urgent repairs would be done first, although a structural survey showed little wrong with the fabric of the building.
Foliage grows from the brickwork and the wind whistles through broken windows. The portico at the entrance would be restored and the top-floor workshops would be made habitable. Most urgently, the building would be made watertight.
"There are no less than seven places in my workshop where I know I can't leave anything overnight in case it rains," said knife maker Mr Mitchell.
The PWC wants to run the site as a "community enterprise of traditional Sheffield crafts, preserved for future generations".