I have searched the forum concerning the question of what are the best sizes of number drill bits that you REALLY use in the hobby, but did not get a real answer. So I would appreciate any opinion or response to the following questions.
I know that grab irons would use #79-#80 bits but what others drill sizes are useful and for what?
I also know that pilot hole for 2-56 tap would be #51 bit but what other sizes for taps would be suggested?
Do you utilize a pin vise or chuck the bit in your Dremel tool? Yup, I do agree breakage is the issue with speed!!
I will steer clear of the purchase of just sets but would select tubes of the needed drill sizes from suppliers Walthers, MicroMark or ModelExpo. Any experience with carbon or high speed steel?
Thanks in advance for sharing your expertise on the forum!!
The size screws you are most likely to use are: 00-90; 0-80; 1-72; and 2-56. On page 898 of the '09 Walthers catalog is a chart of these sizes including clearance and tap drill sizes for those numbered screws. On the same page can be found a tap holder kit. Taps almost always have to be ordered individually and in the case of Walthers run about $4.00 apiece.
Particularly when working with the smaller drill bits and taps breakage can indeed be a problem. Although many modelers get by with just a pin vise for many years sooner or later disaster will strike and then you will find out what it feels like to be up the well-known creek without a paddle. If you think that you are going to be doing a lot of tapping I would give consideration to purchasing a tapping fixture such as is marketed by Micro-Mark.
I bought a 61-80 set and as I broke them I bought replacements in packages of 5 or 10, whatever is available. I found eventually I used many of the sizes. Plus the set included a small case that lets me determine the size of a bit by sticking it in the holes.
I also have regular drill bits from 1/16" up.
I have added others as I needed them.
I have used them in both a pin vise and in my Dremels. I have broken the small ones with both. The Dremel drill press helps cut down the breakage - I have the older one where the table moves not the drill.
First Dean, you didn’t say what scale you model, but since you refer to #79 and 80 for grab irons, it sounds like HO. On top of that, it depends on how deeply you get into the hobby (scratchbuilding and kitbashing bring in a whole new set of requirements) and whether you’ll be building a layout.
If all you’re talking about is installing grab irons, steps, and couplers, you’ve probably already bought what you need. To the second question, we’d need to know what size taps you’re intending to use, each has its own pilot hole size. (PS: for a 2-56 tap, the pilot size is #51 for plastic or other soft material, for metal, it would be a #50). Always use a tapping or cutting oil when drilling and/or tapping into metal. If you’re asking for a recommendation of what other sizes you may need, we’d need to know what you intend to do.
High speed and carbon steel bits will be fine for what you’ll be drilling. Personal preference: for the small bits, I put them in a pin vice and hand drill the holes. Power drilling for anything 1/8 inch or larger.
I know you said in #4 that you will steer clear of purchasing a set, but I would still recommend that you do go ahead and buy a 61-80 set from Micromark or other vendor. That way you will have one of every size drill, which is very handy. As you find out which ones you use the most, you can go ahead and purchase tubes of those bits - you’ll have to anyway due to breakage (it happens to everyone). I prefer to use a pin vice, but it depends on what you are trying to drill through.
The late Linn Westcott, long time editor of Model Railroader, suggested this approach, too. He advised buying a cheap set of bits with the thought that those you wear out or break are obviously the ones you use and the ones you should replace with better quality bits. The remaining cheap ones are those you rarely use and the cheap bits are probably Ok for their purpose.
I suspect there are relatively few if any bits in my standard 61-80 set that I have never used.
I bought an empty drill index years ago. I bought drill bits as I needed them for various projects. After many years the index is full up. But it went for a long time only half full.
I use a pin vise and drill by hand for any holes smaller than a #60 drill. The dremel breaks small drills too fast for my taste. I use my full size drill press set as slow as it will go for bigger holes. The drill press makes straighter holes than hand drilling can.
For hand drilling high speed steel doesn’t offer any advantages. All the Dremel bits used to be advertised as “high speed steel”. The high speed means it stays sharper, long, when it gets very hot. Heat up carbon steel and when it turns blue, you loose a lot of hardness. Drilling by hand, or at slow speed and the drill doesn’t get that hot.
The Dremel 3 jaw chuck is nice, but only fits Dremel. Different thread than my generic roto tool. (got a brand new one if your interested, PM me)
I bought one of those 3 jaw chucks with a 1/8" shaft that fits into a standard collet. Works good. You can use it as a pin vise too.
You can buy higher quality circuit board wire sized bits with 1/8" shafts in case you didn’t know. http://drillbitcity.com/catalogue/25_piece.asp
This place is a little high on their price. They can be found cheaper if you search around.