On Thu, Jul 7, 2022 at 09:17 AM, Kevin Macomber wrote:

How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance

Google "number drill size chart". That will give you the size of number drills in thousandths of an inch, which is the same units of measure used by most hobby wire suppliers. Most pre-forrmed HO grab irons are .012" diameter wire, so a #80 drill at .0135" is just right, leaving some room for glue to surround the wire.

Dennis Storzek

I have been happy with the quality/cost of the drill bits and excellant service from Drill Bit City: https://drillcity.stores.yahoo.net/highspeedtools.html

Fran Giacoma

What sizes are generally required.  How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance.  Kevin

I buy these on ebay, and have never had a problem with them.  

https://www.ebay.com/itm/165010445835

Some sellers have sets.

Rule 1:  lubricate.  I keep a wax block handy and just touch the bit to the wax.  I've never broken a bit in plastic, but have with resin as it's sticky and soft. 

Curt Fortenberry

As I mentioned, the nicely made Otto Frei bits at $0.60 each are my standard now.  If you only want to use the best of everything, USA made precision ground bits from Gesswein at $3 each are also available. I have some in the smaller sizes, but I find they are way overkill for resin and brass.  When the pin vise with a Gesswein bit rolls off the workbench onto the floor, the pain is real...
https://www.gesswein.com/burs-drills/drills-taps-reamers/twist-drills/blue-ribbon-high-speed-twist-drills/

BTW, I too use #79 & #78 bits in most cases. I find the CA fills in that tiny little gap perfectly and takes most of the frustration out of installing grabs and the like.
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RJ Dial
Mendocino, CA

You name the brand or supplier of tiny twist drill bits, I've bought them. I've also thrown out a lot over the years, too.
These from Otto Frei Jewelers are my everyday bits of choice nowadays. High quality and affordable, start nicely and right combination of temper and flexibility for resin and brass.

https://www.ottofrei.com/High-Speed-Steel-Twist-Drills-Sizes-80-to-50
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RJ Dial
Mendocino, CA

  ... I like the style of bit that has a 1/8th inch shaft and necks down to the bit
size.  These often have a collar on them that provides the size info.

  I long ago gave up on trying to hand drill with a #80 and a typical hobby bit.
My solution then - sort of "forced" because I'd just broken the #80 and then
the #79 was to go to a #78 size for holes for #80 size wire ... after the bit is
in you don't notice that the hole is "over sized" and no one has ever said
anything about my holes being too big ... when at least the holes in my
models as opposed to the ones in my head.  *G*
                                                                                         - Jim in the PNW

1.  Go to a Machine Shop Supply and buy a good brand, do not buy the Hobby Shop drills.

2. Buy Screw Machine length drills, they are shorter, so they don't bend as easily.

3. Chuck the drill as short as you can, this also helps with the bending.

My current favorite MSC.

-Hudson

Group,

I know various drilling methods have been discussed before, however, I have not found recommendations for the actual drill bits themselves.  I like to hand drill for grab irons, etc. and will continue to do so.  I have tried several brands of drill bits such as Jobber, Mascot, and Gyros.  I have found the Gyros to be more fragile than the other two.  Are there any suggestions for favorite drill bits from other modelers?  Thanks

Chuck Cover
Santa Fe, NM
PRR's Shamokin Branch