@tim81
As said. Use the tables. Most threading is not critical. But the classes mentioned by
@verbotenwhisky just tells you how tight you want the threads to be for the screw/bolt. If you want a tight thread then the hole size should be small.
I purchased the Starrett 185 and have never regretted it. Mine is SS not black. You can get it on Amazon, or there are cheaper ones but they commonly have punched holes rather than precision cut holes and are not as accurate. I have those too, but always go back to the Starrett. I also have the 186, but I do not use it nearly as often as the drill gage. So you commonly cannot read the drill size on the side of the drill bit, but just slip it into the holes until you find where it just fits and you know the size. I also have a set of 50 and 60 degree centers (like the C391 shown) but by a less expensive supplier. There are tap handles which grip 4 sided tap and there are tap handles which grip 3 sided taps. You just need to know what kind of taps you have!
Drill bits. There are all kinds. I use tables like you posted. I do not usually buy my tools from HF unless I read their reviews and people think they are really good or it is simple and I can look at it and decide it is ok for the money. Much of their stuff is low grade. This is especially true if $$$$ are being spent. Many of their drill bits are soft and quickly wear out... ok for wood for a while. On the other hand I have had decent success with their carbide saw blades. Read the reviews. I needed a right angle drill. Bought one and it quickly broke. I then read the reviews, and guess what. All of them said they were junk. I read the reviews about an electrical hand planer and the reviews were good. I got it and it worked great. I have purchase a lot of drill bits from Grainger.com but a bit more expensive. There is a Grainger store in town. I order on line and then just pick it up. Saves on shipping. Sometimes they have them on close out sale, where they essentially give the parts away! Also, if the metric size is close and is on sale I sometime buy it and use it for the imperial tap hole! Just convert to inches or vise versa. Anyway, drill bits wear out and you have to buy more, so you tend to stock the size that you use. You cannot resharpen the smaller ones by hand anyway. Also not worth it. Taps wear out too. Use oil. I commonly tap at 1/4-20 and 6-32 so I tend to stock up on these drill bits and taps. There are all kinds of taps! You will just have to read about them. Common sizes in Imperial that I use: 10-32, 10-24, 8-32, 8-24, 6-32, 4-40.
As long as you are going to get these things you will also want to get a thread pitch gage. These allow you to measure the spacing of the threads on a bolt to determine what it is. They are cheap and very handy. Something like:
https://www.amazon.com/ChgImposs-Im...&sprefix=thead+gage,industrial,77&sr=1-3&th=1
Vice: I purchased my vice from PM when I got the mill. The one I ordered was out of stock so they just gave me the next size up, 6 inches. It is a nice vice, but it weights in at ~95#. It is precise. I am now older and it is all I can do to lift it to the mill table! I am pretty sure the one I got was this or its equivalent. VISE-HAV-6in-SB-SUPER
https://www.precisionmatthews.com/s...tra-high-precision-milling-vise-wswivel-base/ PM has always treated me right and so I shop with them. Besides they are in Pittsburgh too ... and only about 20 miles from me.
