What size bits?
 

What size bits (ie: 1/4) do you need to make a #rotor style block? This includes making the barbs and for tapping.

my understanding was that the best size bit to drill the block pins was about 4mmØ (or a 5/32" bit). hole depth equal to the diameter (assuming you're using a top and bottom section with pins) probably slightly deeper if you're doing say a copper bottom with a poly top. hope that helps

oops, to answer the part about the barbs, if you're using a barb with 1/4" npt (kinda the standard for hardware stores), to tap that you'll probably need either a 7/16" or 29/64", both of which would work.

What size bits, and tap would i need for half inch barbs?

a) 1/2 inch barbs might be 1/4NPT.

Now, how many bits should I have? There is really no good documentation on this..

like we said, you're probably gonna want a 1/4" npt tap for half inch barbs, but that's one of two or three options. a 1/2" hose barb that you'll typically get at a hardware store can have 1/4", 3/8", or 1/2" threading on it. obviously the 1/4" makes the most sense because it requires the smallest hole and the accompanying tap and drill bit are by far the cheapest of the three mentioned thread sizes. that said, either of the two drill bit sizes mentioned below would work for a 1/4" npt tap. incidentally, that's the name of the tap you'll want, "1/4" - 18 NPT" the 18 referring to the number of threads per inch, a VERY important number to match up (trust me on that, i initially bought a 20 TPI tap, not good)

Could you link me to the EXACT ones I would need? If possible...

Part number 2553A13 on McMaster

Thanks jeff, just what I was lookin for.