The industrial shutdown, which started earlier in the year, has halted all metal production within a 160-kilometre radius of the capital.

The inevitable flow-on has caused a serious shortage in many steel lines used in agriculture, including steel posts and barbed wire.

Farmers, who do most of their fencing over winter, expect to pay 16pc more for wire than they were being charged a month ago, even though steel products had already been rising steeply for six months.

Sales representative at Narrabri, NSW, steel products supplier, Well Australia, Wayne Wheeler, said the price of steel fencing posts rose from $4.95 to $6.80 with the arrival of the new financial year and his company was finding it difficult to find any from anywhere.

“It’s our busiest time of year and we don’t have any posts available,” he said.

“But I believe there was a heap imported and somebody is sitting on them for the time being.”

Nearby, Upper Horton landholder, Peter Cupitt, “Pinaroo” stocked up on the useful items to avoid the July 1 rise, saving himself more than $750 for 400 steel posts.

“They are just something you always need and if I could save that much money then I was going to do it - I got in early and will store them away until they’re needed,” Mr Cupitt said.

At Inverell’s Sapphire City Steel, Graham McLachlan said his firm had also had to find a new supplier for leather rigger gloves from India, because the Chinese tannery which normally supplies them had also been shut down.

“We’ve only got 46 star picket posts left and we are desperately struggling to find more,” he said.

“It’s amazing how dear steel is getting. I went away for a week and sheep yard mesh went up by 25pc.”

In Armidale, NSW, Paul Scales, assistant manager for Metalcorp, said the firm had thousands of posts, after being able to stock up in time for the winter fence repairing.

“We’re having a quieter year because the prices have gone up and most people would rather straighten out their old ones to save a bit of money,” he said.

At OneSteel, Sydney-based Vik Bansal said it was impossible to predict the end of the price volatility, but market indications suggest prices will stay high.

“Global supply and availability of a range of steel products are tightening,” he said.

“It is important to note also that this supply issue is occurring globally, with demand high for the forseeable future,” Mr Bansal said.