Tata Steel closed its Dalzell mill in Motherwell and the Clydebridge plant in Cambuslang with the loss of 270 jobs.
Both were later bought by international metals firm Liberty House which intends to restart production at the Motherwell site in September.
About 60 staff are currently working there, with 40 more recruits expected - many of them former Tata Steel staff.
Liberty Steel said that the Dalzell plate-rolling mill had taken delivery of about 1,500 tonnes of slab steel rom the British Steel plant at Scunthorpe.
This is in preparation for the restart of steel plate production next month.
Jon Bolton, chief executive of Liberty Steel UK plate division, said: "This is a significant milestone for the plates business in Scotland, but also positive news for the UK steel sector as steel once again is manufactured in British Steel's Scunthorpe site to be rolled in Scotland.
"It is pleasing to watch the plant gradually coming back to life as more people arrive on site and particularly pleasing to welcome young apprentices to the team."
Liberty said that about 60 staff were involved in the preparations to reopen Dalzell, with a further 40 expected to join the workforce before production starts.
The firm said that about 70% of the initial wave of recruits were former employees returning to their old jobs.
It has also awarded about 20 new supply contracts, for business and engineering services, to firms in the Motherwell area.
Liberty House Group executive chairman, Sanjeev Gupta, said this was the beginning of the fulfilment of a promise to the local community.
"We said we would revive this historic steelworks and that is exactly what we are doing," he said.

Victor Mlotshwa, 27, told the court how he was forced into a coffin, allegedly by farmers Theo Martins Jackson and Willem Oosthuizen.
The pair deny several charges including kidnapping, attempted murder and possession of an illegal firearm.
The case has caused outrage in South Africa and highlighted racial tensions in the town's farming communities.
A video of the incident was shown in court, in which Mr Mlotshwa was heard crying and pleading.
He told the Middleburg High Court that his mother had sent him to Middleburg, a small farming town, to buy stock for her shop, when he came across one of the suspects while using a foot path as a short-cut through the farm.
Mr Mlotshwa only reported the matter after footage of the alleged assault in August 2016 emerged on YouTube months later.
"I thought these men were going to kill me. They were kicking me with their boots and pressing me down," he told a packed courtroom.
Local papers report that gasps could be heard in the courtroom when a two-minute video of the assault was played, while some people walked out.
Mr Mlotshwa was heard pleading for his life, explaining that he had not stolen and copper cables as they accused him of doing.
He gave a detailed account of how the men bound him with cable ties, beat him and threatened to shoot him if he did not get into the wooden coffin as he was told.
In a court affidavit, the pair, who are out on bail, said they didn't mean to harm him but merely wanted to "teach him a lesson".
The trial continues on Friday.

The 36-year-old, who has won 94 caps for his country, leaves Munster after 270 competitive appearances in 17 seasons for the Irish province.
"Donncha has tremendous know-how at the highest level," boss Dean Ryan said.
"To bring in someone with such international and European experience is a real coup for the club."
O'Callaghan, who also made four appearances for the British & Irish Lions in 2009, has played in three consecutive World Cups for Ireland and helped to win the Six Nations Grand Slam in 2009.
He has also picked up two Heineken Cup winners' medals, along with two Magners League titles, for Munster.
"I'm very grateful to Munster for all that they've done for me," he said. "But now I'm hungry for my new challenge.
"I watched the Bristol game where Warriors turned it around in the last seven minutes at the end of last season, and that was really impressive."
There may be more new signings at Sixways before the new Premiership season kicks off at home to Northampton on Friday, 16 October.
Experienced Springbok centre Wynand Olivier is also reportedly set to sign on a two-year deal following his release by Montpellier.
Steel production is set to resume next month at one of two Lanarkshire plants that were mothballed last year.
[NEXT_CONCEPT]
The victim in South Africa's coffin assault case has broken down during the trial of his alleged attackers.
[NEXT_CONCEPT]
Worcester Warriors have made their 11th pre-season signing by bringing in vastly experienced Munster and Ireland lock forward Donncha O'Callaghan.