Built like a tank and almost as heavy - Pentag’s gear cutters look positively steam powered.
“Next stop Kelham Island Industrial museum,” jokes sales manager Mark Crossley.
The two Sunderland 22 tonners, and a handful of other machine tools from the 1950s and 1960s, look like what they are - vital kit that has been used almost daily for up to 60 years.
But they are a long way from being museum pieces.
One Sanderson has been operating for 20 hours, cutting teeth into a big steel disc which inches round, as a cutting head moves back and forward, splashed by a little waterfall of lubricating oil.
For not only are they still working perfectly, the ‘Sanderson 27 Double Helical’ is capable of cutting an eight-foot ring gear and is believed to be the only one of its kind in the country.
‘Big and bespoke’ are Pentag’s selling points.
Mark added: “They were built to last. Everything is mechanical, if it breaks we can mend it.”
The machines make gears - pinions, gear rings and gear trains - for the oil and shipping industries, as well as escalators for Transport for London and crushers for the quarrying sector.
But today they are working for a new owner in a new location.
Pentag, which can trace its roots back to 1890, was snapped up by BG Engineering in Chesterfield earlier this year.
It took six weeks to move the plant from John Street in Sheffield and involved digging them out of concrete foundations.
For some it was the third time they had relocated after they were originally installed on Edmund Road, Highfield, during the heyday of Aurora Gearing which succeeded the original company Wilmot North.
Production manager Andrew Larkin, who joined Pentag in 1987, said: “Edmund Road was like going back in time. The company had bought terraced houses one by one and knocked them through, removing fireplaces as they went.
“I worked with a lot of guys in the 1980s who had been there for 50 years and they remembered materials being delivered by horse and cart.
“In the early 20th century Aurora had 150 machinists and maybe 60 office staff. When I joined Pentag there were 50 machinists. By 1991 it was down to 17.”
At that time, when it was busy Pentag used a bay in DavyMarkham’s giant workshop in Darnall. The famous firm, which finally went out of business earlier this year, used to do its own gear cutting - really big stuff of course - but mothballed the division in the 1990s, Andy said.
He and Martin Wragg bought the company and down sized it in 2004. They sold to BG, owned by Cooper-Brown Enterprises, as part of an exit strategy for Martin.
Its new owners are looking at moving into aerospace.
Andrew, who is now production manager, said: “Marie Cooper had got the drive to do something with Pentag. We had a successful business but we never really did much with it. But under Marie and Chris Brown it will thrive. It was a tough decision to sell but it couldn’t have been to better people.”
In 2016, Pentag found fame when it made eight gears for the thrusters on £200m polar research vessel RSS David Attenborough - which some on social media wanted to call Boaty McBoatface.
In the end the joke name lived on in its remote controlled sub.
Andy added: “The association with the boat was good but it’s the sort of thing we’ve done many times for others.”
PENTAG’S OILFIELD PUMPS GET THE NOD IN DORSET – AND THE MIDDLE EAST
Nodding Donkey pumps are an iconic feature of giant Texan oil fields, but there are more than 30 in Dorset, England, all made by Pentag.
The company supplies the Wytch Farm oil field which is pumping crude oil and natural gas from under Poole Harbour.
New extraction technologies mean the life of the site keeps being extended, up to 2040 currently, according to production manager Andrew Larkin. And that means continued business making and servicing ‘beam pumps’.
Pentag also sells them to an oil field in Lincoln as well as sites in Iraq, Oman, Kuwait and Saudi Arabia.