so i need to put threads on a 1/4" diameter steel rod and i want to tap a piece of steel to thread it into. what size hole do i need to drill and what size tap do i need for said steel rod to fit? (i would like it to be fine threads too. if possible.)

1/4 fine thread is 1/4 - 28. the tap drill size is #3 drill .213

When a question like this comes up I have a little black book "Glover's Pocket Reference" do a google and you'll see them listed for 9-15 dollars. I'd buy one for 30 if I lost mine. (course if it was all that was available, otherwise I want the 9 dollar one) It has the details of drilling and tapping as well as plumbing carpentry welding money countries.. neat little book. If you need more in depth questions answered shop for a used Machinerys' handbook. I got a couple off of ebay several years back.

Look here....

http://www.kramerusa.com/DrillTapChart.htm

Print the chart out and keep it for future reference...