China’s hot-dipped galvanized coil export market strengthened this week on tight supply and higher domestic hot rolled coil prices.

Base transaction prices for HDG were at $645-665 per tonne fob for October shipment on August 7, up $25-30 per tonne from a week ago.

Base offers for the product also rose to $670-680 per tonne fob, from $645-650 per tonne a week ago.

“HRC prices are higher, so we followed the trend and raised our prices,” an exporter at a mill in Jiangsu province said.

The mill stopped issuing offers last week while it waited for Shagang’s HRC list prices, he said.

East China-based Shagang raised its HRC list prices by 170 yuan ($28) per tonne on August 1.

Supply tightness was also widely reported in the market.

“We are carrying out maintenance works on our HRC production lines, so our supply of HDG will be tighter,” an exporter for a major north China-based mill told Steel First.

Strict inspections by environmental authorities in north China also forced many mills to reduce output, market participants said.

Traders’ inventory is also at a low since mills are controlling their deliveries to the market, which supports prices but slows down trading activity, a Shanghai-based trader said.

Spot prices for 1mm HDG in Shanghai were at 4,470-4,630 yuan ($724-750) per tonne on Wednesday, unchanged for the week.