The incident occurred in the small hours of today when a four-member gang entered the workshop and sprinkled chilli powder in the eyes of Nagaraj, who tried to resist them.
The gang fled with nearly one kg of gold and gold ornaments, they said.
Another worker, Saravana Kumar who had gone to buy tea, later returned and informed the owner, who in turn alerted the police.
On receiving information, police reached the spot with finger print experts and sniffer dogs, they said.
Police are trying to acquire the CCTV footage from a nearby building to identify the robbers, they added.