Pen Kit Drill Bits

[Sappheiros]

Tomorrow is the day I start turning! I have everything I need and I'm going to start with the elegant slimline kit. I know most of the kits require the 7mm drill bit for the blanks. Of course, they only label the bits by fractions or decimals.

I've got the Dewalt 29-Piece Titanium Pilot-Point Drill Bit Set. I thought 1/4 was the right bit to use, but that one was too small. Do I need to buy another bit set?

 

[magpens]

If you are starting with slimlines (not the simplest or easiest kit, by any means) then most likely you should start with a 7mm bit which is 0.276"; and the closest sizes in the 29-piece set you have would be 9/32" which is a little oversize at 0.281", or 17/64" which is a little under at 0.266". Frankly I would try the undersize first and go from there. You can sometimes enlarge successfully with a small rattail file used carefully.

BTW, the actual size of the slimline tube is 0.267", so you now have all the data to make your choice ... ... hope you work out something that works for you.

A 7mm drill bit can probably be found at a tool store near you; and certainly can be ordered from one of our suppliers represented here.

 

[KenV]

Avi; the convention with pens is to reference the hole size that is normally used to accommodate the brass tube. There are often a similar size bit that can be used if the hole is a bit off with the techniques being used. I usually paint the inside of acrylic blanks and use a slightly larger bit to give some space and avoid scraping paint off.

 

[Charlie69]

A guy with a lathe can never have enough drill bits...I would return the Dewalt set and get a set like this from HF 115 Pc High Speed Steel Drill Bit Set with Index

 

[mecompco]

If you're going to be doing a LOT of 7mm tubed pens, this is a pretty good deal. At just over a buck a piece, they are almost disposable. These work much better than the crazy brad-pointed ones you get from the pen companies.

http://www.amazon.com/gp/product/B008IGRXWG?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00

 

[Kragax]

My 10mm holes were out of round. I checked the lathe, found my jacobs chuck to have some play but not bad. The culprit was a bit from psi that actually was bet a slight bit. It's always something.

 

[Penultimate]

A guy with a lathe can never have enough drill bits...I would return the Dewalt set and get a set like this from HF 115 Pc High Speed Steel Drill Bit Set with Index

I have a similar 115 pc set. Measure each bit before use some are slightly undersized. I found a bent bit and replaced it with a better one. It is a good starter set and most of the bits are good enough for our purposes. You will need letter and number bits when you start tapping for kitless pens.

 

[Charlie69]

I don't have extensive experience with a lot of drill bits from different manufacturers but it does seem that bits are typically undersized. Not just the less expensive imported ones either. I have some nice new old stock Butterfield bits that all mic out small on my Mitutoyo mics and calipers. I recently got triple start 11mm tap and die and a 10.25mm Butterfield machine screw bit (10.19mm) was way too tight for the tap. Y bit from my HF tin coated set worked good. Gonna try a 13/32 next and see how that works.

 

[thewishman]

The best bit for me is the letter J bit. I love the TiN HF set, as you find which bits you use most, you can buy upgraded replacements.

 

[magpens]

I have never been sorry that I "bit" the bullet and bought 3 Norton sets - fractional, metric, and letter - close to $300 CDN but well worth it IMO.

 

[Skie_M]

Most issues with the "undersized" bits may be explained by the "head" of the bit that does the cutting action being slightly larger than the "shank" of the bit, with the flutes that ride the cut particles away, so that the "shank" doesn't bind in the hole you are drilling.

Make sure you measure the head of the bit as well as the hole size it actually cuts.

 

[Sappheiros]

Thanks for all of the advice! I love how great the community is here. Turning has turned out to be really great! It's definitely not an exact equation. I ended up picking the bits closest to the size of the brass tubing and made the Slimline and a Jr. Gent as well. I'll be posting to show off soon!