BEIJING, July 19 (Reuters) - Shanghai steel rebar and hot-rolled coils futures rose on Monday amid concerns of supply crunch as top steel producer China stepped up production curbs, while utilisation rates of blast furnaces at key steel mills remain relatively low.

Capacity utilisation rates of blast furnaces at 163 steel mills across China fell to 76.81%, as of July 16, from 77.61% the week earlier, data from Mysteel consultancy showed. That compared with 85.6% in the same period a year earlier.

"Currently, the biggest variate to affect steel prices is crude steel output control policy ... which is gradually being implemented and widened," analysts with Huatai Futures wrote in a note.

Meanwhile, the limit to power consumption due to high temperature in Henan province also led to lower steel production, said Huatai.

The most-traded steel rebar on the Shanghai Futures Exchange , for October delivery, jumped 1.6% to 5,611 yuan ($36,352.45) per tonne by 0330 GMT.

Hot-rolled coils, used in the manufacturing sector, rose 1% to 5,991 yuan a tonne.

However, with Beijing still keeping a close eye on commodity prices and vowed to crack down on market irregularities, analysts warned of policy risks with steel prices hovering at high levels.

The August contract for stainless steel futures on the Shanghai bourse dipped 0.1% to 18,705 yuan a tonne.

FUNDAMENTALS

* Benchmark iron ore futures on the Dalian Commodity Exchange, for September delivery, fell 1.8% to 1,221 yuan per tonne.

* Dalian coking coal gained 1.5% to 2,060 yuan a tonne and coke futures edged up 0.3% to 2,675 yuan per tonne.

* Spot prices of iron ore with 62% iron content for delivery to China increased $1.5 to $223 on Friday, according to SteelHome consultancy.

($1 = 0.1544 yuan) (Reporting by Min Zhang and Shivani Singh, Editing by Sherry Jacob-Phillips)