Drill bit sizes

[Woodster Will]

Do you folks just use the size recommended by the kit suppliers instructions or do you measure the tubes and use a different drill if required?
I ask because I've just got a kit and the recommended drill sizes are 10.5 and 12.5 but when I measured the tubes with a micrometer they are 10.22 and 12.3 respectively. I know I need room for the adhesive but even so the recommended drill sizes seem a bit off. What do you think?

 

[PenPal]

When I buy drill bits for special purposes I caliper them at the source of purchase. I often buy one above in mills and one below as the Irish say to be sure to be sure. The UK abounds in reliable drill sellers. But the best and lessen the anguish.

Kind regards Peter.

 

[Silver]

I use one of these in metric and imperial.

SILVERLINE ENGINEERS HANDY DRILL GAUGE IMPERIAL 1/16" TO 1/2" STAINLESS STEEL | eBay

Never go by the drill size recommended on the instructions as it takes longer to find the instructions than stick the tubes in a gauge.

 

[randyrls]

William; I have a complete set of 115 bits, Fractional, Letter, and Number. I have often found that the drill bit specified in the instructions is not the best one. It is likely the closest commonly used size. I have a set of 115 drill bits that include fractional, letter, and number. I also have a set of metric. Odd ball drill sizes can be had at MSC.

When drilling a new pen style or type, I drill the hole under-size the first time, and then check the fit with the tube. When I find the correct bit to use, I write the bit size on the instruction sheet. The instruction sheet goes in my binder. There is a small difference of a few thousandths of an inch between drilling wood and drilling acrylic. The drill bit drills a slightly larger hole in Acrylic.

There are several Drill bit charts in the IAP Library.

 

[Woodster Will]

Thanks guys, seems like we're on the same page with this!

 

[leehljp]

IN addition to what Randy wrote above concerning the 115 drill bit set, I use a chart similar to the one in the IAP library:
http://content.penturners.org/library/general_reference/conversions.pdf

With the chart and the drill bits, It is easy to figure which bit to use to fit what one wants.

Also, many people use the Drill Doctor (500 or 750) to keep the bits sharp.

 

[Woodchipper]

Randy, good idea. Where did you get the drill bit set? Might get one for SWMBO for a Christmas present. Won't she be surprised!

 

[JimB]

I usually take the recommended size bit and test drill in a piece of scrap wood to see how the tube fits then make a determination as to what bit I will actually use. The downside to my method is different material drill differently so if the scrap isn't the same as the blank there can be differences.

I bought my 115 bit set from Harbor Freight and keep them sharp with a drill doctor.

 

[Woodchipper]

Harbor Freight!!! Got a 25% coupon for Labor Day! Thanks!!!!!

 

[randyrls]

Randy, good idea. Where did you get the drill bit set? Might get one for SWMBO for a Christmas present. Won't she be surprised!

I have a cheap set for drilling pens from Grizzly and a metric set 3mm to 13mm in .5mm steps. I also have a Chicago-Latrobe 115 piece drill bit set from Enco about $300 if I remember correctly. When you use a bit, make a mark on the shaft. when enough marks accumulate, go get a single good quality bit like Norseman. The Grizzly set is about $50 to $80 depending on which one you get.

I'd re-think that present

 

[leehljp]

The HF 115 piece set comes in 3 grades:
Regular: https://www.harborfreight.com/115-pc-high-speed-steel-drill-bit-set-with-index-61620.html
Titanium: https://www.harborfreight.com/115-pc-titanium-m2-high-speed-steel-drill-bit-set-61543.html
Cobalt: https://www.harborfreight.com/115-pc-cobalt-drill-bit-set-61886.html

I have the Cobalt and Titanium. The Cobalt are twice the price but worth it in the long run.

 

[magpens]

I rarely use the recommended drill bit size.

I measure the tubes and make my own call.

I think it is important to have a wide selection of drill bit sizes ... fractional, metric, letter, and number. . I also find "odd" metric sizes useful like 9.6 mm and 10.7 mm, for example.

 

[Woodster Will]

I've had a large selection of twist drills in odd sizes for quite some time as I've needed them in metal work projects I've done. I'm now buying some fresh bits though just for use on wood. I'll set these aside with my pen making bits.
Recently bought 10.3 & 10.4 to go with a 10.5 I already had. Also got 12.3 and 12.4. I'll fill in the other gaps as I need them. Luckily these days there are suppliers on eBay that sell metric bits in .1mm increments at a reasonable price. Presto and Dormer make great drill bits but the prices are often eye watering! :tongue:

 

[Woodchipper]

Lee, thanks for the links. I'll go with the titanium. If I did a lot of metal work, I would definitely go with the cobalt. Going to have a long list for HF and Woodcraft.
magpens, I have been around manufacturing for many years but wasn't aware of the odd metric sizes you listed.
Remember, the one who dies with the most tool, wins!!!

 

[SteveG]

After a few years at pen turning (experience), multiple years at IAP (other peoples experience), Drilling with medium-to-poor quality drill bits (school of hard knocks), I finally got serious about getting the RIGHT drill bits. I considered the thought to buy a complete set (115 pc) of less expensive bits (already having most of the often used ones in high quality grade). Then I paused long enough to consider all that I just mentioned here plus other bits and pieces of wisdom from a variety of sources. I took the plunge, spent a little under $300 and now happily own a 115 piece set of Norseman Super Premium drill bits. I have not regretted that purchase, not even once, and highly recommend the experience to all. These drill bits show up at your door, already VERY sharp and of course, VERY straight. After lots of use, the Drill Doctor is at the ready!