bandwidth limit 512kbps on cisco c3560 switch

i am working for an ISP. there is cisco catalyst 3560 switch. i cant limit bandwidth maximum 512kpbs on a port.
i also try srr-queue-bandwidth limit 10.
but it can limit minimum 1 mbps to 90 mbps.
is it possible that limit bandwidth on a port maximum as 512kbps or less then 1 mbps.