Thread: Standard drill sizes

OH! how I wish it was that easy!!! sometimes a Sierra from one company uses a different size than a Sierra from another!!??? and same goes for all kits from different manufacturers, always check from them or their website as to sizes for drills and bushings, do not assume that you can interchange kit parts. Amos

Ah yes!! The intricacies of pen kits and drill sizes!!

Be prepared to fork out for metric, imperial and letter sizes!!!

can you get away to with sticking with metric drills in your blanks or is it really a case of imperial as well.

I get not being able to some pen parts etc. At this stage Im just workingon something and if you can get away with metric I am just after the main size bits I need when it comes to gluing in tubes.

so completey forgetting the kit variations and names just after the right size bits for the range of different tube sizes.


Dave the turning cowboy

turning wood into art

That is just it Dave, different kits use different Tube Sizes, and just a fraction under and you are stuck, sometimes a fraction larger can be disguised by using epoxy resin when gluing in(to fill the extra room). Then for turning you do need the perfect fit for the Bushes to go inside the tubes and not wobble. Unless you make your own bushes)
I ended up buying a good set of Imperial, a good set of Metric, and then the special sizes for the high end kits(the drill bits for the special sizes can be $35 ea at an Engineering shop. Amos

I had to start a spreadsheet for all of my pen kits! So many different sizes for different kits. Here's my stash:

7mm - Slimline / Streamline / Keyring etc
8mm - Perfume kit
3/8" or 9.5mm - Executive Clicker (Timberbits)
10mm - Cigar, Baron, Sedona, JR Gents (small tube)
10.5mm - Sierra (Timberbits)
11.5mm - SN Gents - Timberbits (small tube)
11.9mm - Baron, Sedona, JR Gents (large tube)
12.3mm - Roman Harvest - Timberbits (small tube)
13.1mm - Roman Harvest - Timberbits (large tube)
37/64" or 14.5mm - SN Gents - Timberbits (large tube)

The difference between metric and imperial becomes much more important when your drill size increases, as there is more possibility it is a long way out. For example, I have to use a 37/64" drill bit for the large tube of a SN Gent pen. The equivalent closest metric drill bit you can get would probably be 14.5mm, but actually 37/64" is 14.68mm in size. There is a lot more room to maneuver using a 37/64" in that case than a 14.5mm bit. Apparently the brass tubes are 14.47mm external diameter, so in theory a 14.5 would work, but using imperial gives you a lot more room for the glue to make contact (not too much though!)

thanks simon, that gives me something to start on


Dave the turning cowboy

turning wood into art

Dave,

One of the other variables is not just the tube size but the kit outside diameter too. Some kits have much less material left on the tube at the finished size than others. Obviously kits that allow for much more material left on the tube are a little more forgiving when it comes to a slightly oversized hole to the outside diameter of the tube size and the glue taking up the slack, if that makes sense for most of the kits I have done and I have done a few I use metric moving up in .5mm steps and I have found that accommodates most

Cheers
Tony

Thanks Tony, that is useful too.

Does everyone use brad points?


Dave the turning cowboy

turning wood into art

Good question. Brad points will get you a very even hole when drilling, but difficult to find in the larger sizes. I use HSS drill bits but they are all standard twist bit not Brad point.

With a couple of the larger ones I had to order the drill bits online from all around the country. It was hard enough trying to find them in the size, let alone in HSS or a brad point bit.

When you really get into all the kits you will need many many drills, but don't stop there, you may also need honing drills too for those blanks where you paint the inside and the imperial/metric/lettered kits still aren't enough .

Ok Neil .... educate me. WHat is a honing bit and how does it differ to a regular bit?


Dave the turning cowboy

turning wood into art

Originally Posted by DaveTTC

Ok Neil .... educate me. WHat is a honing bit and how does it differ to a regular bit?


Dave the turning cowboy

turning wood into art

Hehe! my "honing drill" is a round file Sometimes you can use exactly the right drill for the job ,but the wood moves a bit (usually shrinks) and the tube won't fit so a round file will bring it out a bit for a looser fit. I tend most times on bigger pens to drill very close to size as a lot of time there is very little material on the tube once turned and sanded, I'd much rather file it out a bit than have not enough material left to work with ,especially burls and some of the more difficult materials . A full set of metric and imperial drills is not that expensive these days and that will cover you up to 13mm . I know Neil often seals the inside of his blanks with thin CA ,especially with some of his special casts where you may have wood and acrylic mixes or something more exotic
In those cases I think Neil just redrills (or reams) with the correct size drill for his tube to fit ,and room for glue or epoxy . Cheers ~ John

Originally Posted by DaveTTC

Ok Neil .... educate me. WHat is a honing bit and how does it differ to a regular bit?

They are called adjustable reamers, to ream any hole that little bit larger

reamer set.jpg

Originally Posted by gawdelpus

...I know Neil often seals the inside of his blanks with thin CA ,especially with some of his special casts where you may have wood and acrylic mixes or something more exotic In those cases I think Neil just redrills (or reams) with the correct size drill for his tube to fit ,and room for glue or epoxy . Cheers ~ John

Yep