Rebar on the Shanghai Futures Exchange (SHFE) fell as much as 0.8% to 3,483 yuan ($478.73) a metric ton, the lowest since April 8.
The contract was down 0.7% by the midday break.
Latest data from China showed domestic demand continued to recover at a slow pace, and construction data showed double digit percentage fall in the first five months of the year.
SHFE hot-rolled coil steel dropped to as low as 3,687 yuan a ton, a level unseen since April 8.
It was down 0.5% at 3,688 yuan at the midday break. SHFE wire rod steel shed 0.7% to 3,665 yuan a ton and stainless steel dropped 1.2% to 13,955 yuan.
