# Best drill bit.



## Ddw04

So originally I was using a 9/32 drill bit cause it matched the brass tubing perfect, but after watching a YouTube video it mentioned that the instruction manual that comes with them suggests a 7mm one. I'm really confused. What is the best drill bit to use on wood and acrylic blanks? And if possible one to use on all types of wood


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## PenPal

The one that does the job easily and well for you. Too much is said on this subject that is not even valid the most often quoted how expensive, my experience tells me it is one of the small costs in penmaking when amortised against the number of good clean holes you get from a drill.And yes I use the drill that i prefer ie one with a drill point front from the yellow brand firm.Not unusual to get into the hundreds of trouble free holes from one drill.Rely on your own experiences. When it came to drilling a Mammoth Tooth  I chose a special drill because of the fossilised material followed by a conventional drill to the finished size,I use my normal drills for timber and plastic ,blowouts are rare . 

What pen do you quote?

Kind regards Peter.


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## randyrls

Ddw04 said:


> suggests a 7mm one.



The one that gives you the closest hole is the right one.  If the 9/32" bit gives you the best fit, that is the right one to use.  You want a sliding slip fit with as little slop as possible.  The instructions have the *closest most commonly available drill bit*.  That isn't always the best one.  eg.  I use a letter "I" (eye) drill bit for 7mm brass tubes.  There is a small (.003-.005")  difference in the size of the hole between acrylic and wood.  Hole in acrylic is larger than wood with the same drill bit.

Hope this helps....


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## jttheclockman

Can not tell you exactly because acrylic and wood can and usually do drill differently and this is because wood fibers may lay down while being drilled but pop back up after and you may get a tighter fit. Thus a tab bit bigger bit. A complete set of drill bits both numbered and letter helps alot in this hobby. Instructions are sometimes suggestions and there is no dead fast rules to follow. As mentioned you want a nice slip fit with little play because you glue of choice will become important there.


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## Ddw04

randyrls said:


> The one that gives you the closest hole is the right one.  If the 9/32" bit gives you the best fit, that is the right one to use.  You want a sliding slip fit with as little slop as possible.  The instructions have the *closest most commonly available drill bit*.  That isn't always the best one.  eg.  I use a letter "I" (eye) drill bit for 7mm brass tubes.  There is a small (.003-.005")  difference in the size of the hole between acrylic and wood.  Hole in acrylic is larger than wood with the same drill bit.
> 
> Hope this helps....


I just dont want to buy one and it works great for wood and I attempt it on my acrylic pieces and it just completely ruins it cause it wasnt meant for acrylic


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## leehljp

Four things that can help:
1. a set of drill bits such as the 115 bit set from HF such as these: https://www.harborfreight.com/115-pc-titanium-m2-high-speed-steel-drill-bit-set-61543.html
2. Drill Doctor 500 or better for sharpening
3. Drill bit chart for comparing actual size of bits from metric to inch to letter to number
4. GOOD set of calipers (and something your wrote or said seems to indicate that you may have a set)

A drill chart can be downloaded here: https://www.penturners.org/resource...imal-number-letter-drill-sizes-and-metric.49/
A drill chart lets a person find out which next size up or down can be had. Sometimes a metric or inch or fraction or number or letter might be the next best bit.

"Sharp" means different things to different people and when the term is ambiguously subjective, it won't get the job done. If resistance is felt, most of the time it is because of dullness.
Some people do have problems, but in the 14 years I have been making pens, I have not had a problem with the same bit drilling on different woods, and on acrylic or on segmented drilling through wood and metal.  If a single bit works in wood but not in acrylic, it is a subjective/ technique problem, IMO, not a peculiar "bit" problem. That said, I do have brad point bits but do not use them on segmented with metal.


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## monophoto

When I first saw this question, I was reminded of a situation in a camera club that I'm a member of.  Frequently, someone will ask 'what's the best camera for - - -?'  When that happens, my friend Max (originally from New York City and a bit of a smart-ass) always responds  'for that you need a plaid one'.  He then goes on to point out, very correctly, that a camera is just a tool, and the key to using it for an application is in knowing how to use it.

So my smart-ass response to the question 'which is the best bit' is 'the sharp one'.    The hole has to be straight, and the diameter has to be large enough to receive the tube, but no so large that the glue can't form a bond between the tube and the walls of the hole.  The best way to achieve that is to use a sharp bit.

I agree with Hank - having a full 115 bit set is really convenient.  I have the Harbor Freight set that I reserve exclusively for driling soft material like wood, and a box of other bits that I keep for metal.  I keep them sharp using a diamond paddle  -  one of these days I'll invest in a Drill Doctor, but a Drill Doctor won't sharpen bits smaller than 1/8", whereas I can easily tune them up using a diamond paddle.  And frankly, smaller bits have another problem - they can break just as easily as they can dull. 

I have several plastic drill bit gauges that I got from a magazine that was trying to sell me a subscription, and you can purchase metal gauges at most hardware stores.  Rather than a drill bit chart, I use an iPhone App called iEngineer that includes information on both imperial and metric screws, bolts and drills (including information like the required pilot hole size for threading holes).


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## leehljp

monophoto said:


> . . .  Rather than a drill bit chart, I use an iPhone App called* iEngineer *that includes information on both imperial and metric screws, bolts and drills (including information like the required pilot hole size for threading holes).



THANKS Louie. I just downloaded it and most certainly will be using it! This is great!


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## Ddw04

leehljp said:


> Four things that can help:
> 1. a set of drill bits such as the 115 bit set from HF such as these: https://www.harborfreight.com/115-pc-titanium-m2-high-speed-steel-drill-bit-set-61543.html
> 2. Drill Doctor 500 or better for sharpening
> 3. Drill bit chart for comparing actual size of bits from metric to inch to letter to number
> 4. GOOD set of calipers (and something your wrote or said seems to indicate that you may have a set)
> 
> A drill chart can be downloaded here: https://www.penturners.org/resource...imal-number-letter-drill-sizes-and-metric.49/
> A drill chart lets a person find out which next size up or down can be had. Sometimes a metric or inch or fraction or number or letter might be the next best bit.
> 
> "Sharp" means different things to different people and when the term is ambiguously subjective, it won't get the job done. If resistance is felt, most of the time it is because of dullness.
> Some people do have problems, but in the 14 years I have been making pens, I have not had a problem with the same bit drilling on different woods, and on acrylic or on segmented drilling through wood and metal.  If a single bit works in wood but not in acrylic, it is a subjective/ technique problem, IMO, not a peculiar "bit" problem. That said, I do have brad point bits but do not use them on segmented with metal.


Thanks so much but sadly I do not have a set of drill bits. 

Also what are calipers? In the sense of what your referring I use them for?


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## Ddw04

Also since I dont really know how long I'm gonna be doing this stuff I dont want to be buying that many drill bits I may just but a 7mm brand point one every so years.


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## monophoto

Ddw04 said:


> Also what are calipers? In the sense of what your referring I use them for?



Calipers are a device used to measure the diameter of either a shaft (using 'outside calipers') or a hold ('inside calipers').  Actually, most calipers today can do both inside and outside dimensions.

Calipers come in three varieties - analog calipers have a simple calibrated scale engraved on the body of the caliper, and a pointer that tells you the dimension of the shaft (when the calipers close down on a shaft), or hole (when the caliper expands to the diameter of the hole).  And most importantly, they have a locking screw so that you can measure the inside diameter of a hole, lock the caliper, and use the outside diameter measurement as a gauge when you turn a shaft to match.  That is, the potential inaccuracy of an analog measurement doesn't matter because rather than reading the measurement, you use the caliper to simply transfer the measurement from one piece to another.  The accuracy of a vernier caliper depends on its length - a typical 6-8" caliper is probably good down to 1/16", but a longer (and more expensive) caliper can be used to get more precise measurements.

There are special versions of analog calipers called 'vernier' calipers - these have two scales, one to read the total dimension, and a second that helps you interpolate between markings on the  main scale.  It takes time and experience to learn how to use a vernier caliper.

Dial calipers have a dial and moving needle - and so are more accurate than analog calipers in when used to make measurements.  But they are no better than analog calipers if you use them to transfer measurements.  A 6-8" digital caliper typically can read to three decimal places in either metric or decimal imperial measurements.

Then there are digital calipers - calipers with a digital readout, often one than can be switched between metric, fractional imperial, and decimal imperial.  The measurement is more precise, but the key feature is the ability to transfer measurements without actually reading the dimension.  The major downside of digital calipers is that they eat batteries.

Better calipers are made of steel, but you can buy less expensive plastic calipers.  A plastic analog caliper will cost about $5, while a steel digital calipers start around  $15  but can be far more expensive depending on the quality.    

While calipers are intended mainly for measuring diameters of shafts and holes, most can also measure the depth of a hole.  

Quality varies considerably, but for wood turning you don't need the same quality that you might want in a precision metal shop.  Harbor Freight has fairly inexpensive plastic and steel analog calipers, and their steel digital calipers aren't all that bad.    Brands like Starret are at the other end of the scale and are very expensive.


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## monophoto

Ddw04 said:


> Also since I dont really know how long I'm gonna be doing this stuff I dont want to be buying that many drill bits I may just but a 7mm brand point one every so years.




Two comments.  First, purists would point out that while pen kit suppliers tend to direct you to brad point bits, they may not be the best choice.  The supposed advantage of brad point bits is that you don't need to drill a pilot hole, but the other side of that coin is that a brad point bit can 'wander' off axis as you are drilling, especially in wood.  What happens is that if the brad point (or spur) encounters a boundary between harder wood and softer wood (ie, wood that grew in the winter versus wood that grew in the summer), it will try to remain in the softer wood.  That means that if the blank has a pronounced grain pattern, the bit can actually drift quite a bit off axis.  What in effect is happening is that the bit flexes.  This is far more likely to occur with smaller diameter bits, but it can happen with the usual 7mm bit used in making pens.  

So a better solution is to drill the hole in three steps.  First, use a 'center bit' to start the hole.  Center bits are special, short bits that are fat enough that they won't flex, but that are tapered to start a very small hole.  Second, use a smaller 118 degree twist drill bit (that will 'center' in the dimple created by the center bit) to drill a hole to the desired depth.  Finally, follow up with the proper bit  (again a standard 118 degree twist drill bit) to enlarge that hole to the desired diameter.  Obviously, three bits means more expense, and also more time, but the process is more accurate.

That said, a lot of people do use brad point bits.  There are two secrets to success.  First, drill slowly - let the leading edge of the bit cut a hole in the timber before you try to move the bit into that hole.  If you drill too fast, forcing the bit into the timber, you increase the risk of it wandering off axis.

Second, the bit needs to be sharp.    It's more difficult to sharpen brad point bits than standard twist drill bits, and the low-end Drill Doctor machines aren't designed to handle brad point bits.  But you can 'tune up' the cutting edge of brad point bits using a diamond paddle.  If you invest in and use a diamond paddle, you should be able to get many years of use out of a brad point bit.


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## Ddw04

monophoto said:


> Two comments.  First, purists would point out that while pen kit suppliers tend to direct you to brad point bits, they may not be the best choice.  The supposed advantage of brad point bits is that you don't need to drill a pilot hole, but the other side of that coin is that a brad point bit can 'wander' off axis as you are drilling, especially in wood.  What happens is that if the brad point (or spur) encounters a boundary between harder wood and softer wood (ie, wood that grew in the winter versus wood that grew in the summer), it will try to remain in the softer wood.  That means that if the blank has a pronounced grain pattern, the bit can actually drift quite a bit off axis.  What in effect is happening is that the bit flexes.  This is far more likely to occur with smaller diameter bits, but it can happen with the usual 7mm bit used in making pens.
> 
> So a better solution is to drill the hole in three steps.  First, use a 'center bit' to start the hole.  Center bits are special, short bits that are fat enough that they won't flex, but that are tapered to start a very small hole.  Second, use a smaller 118 degree twist drill bit (that will 'center' in the dimple created by the center bit) to drill a hole to the desired depth.  Finally, follow up with the proper bit  (again a standard 118 degree twist drill bit) to enlarge that hole to the desired diameter.  Obviously, three bits means more expense, and also more time, but the process is more accurate.
> 
> That said, a lot of people do use brad point bits.  There are two secrets to success.  First, drill slowly - let the leading edge of the bit cut a hole in the timber before you try to move the bit into that hole.  If you drill too fast, forcing the bit into the timber, you increase the risk of it wandering off axis.
> 
> Second, the bit needs to be sharp.    It's more difficult to sharpen brad point bits than standard twist drill bits, and the low-end Drill Doctor machines aren't designed to handle brad point bits.  But you can 'tune up' the cutting edge of brad point bits using a diamond paddle.  If you invest in and use a diamond paddle, you should be able to get many years of use out of a brad point bit.


Ok thanks.     *sigh* this seems so much more complicated then when I did it in school or with my dad. It's so overwhelming with the amount of stuff I need. When me and my dad did it he bought the lathe, drill press, sand paper, blanks, mini band saw, glue and I think had a lot of drill bits and that's it.


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## Ddw04

My dad isnt around anymore and so I cant just buy things since it's just me and my mom and we dont really know a lot about this stuff. And it's becoming overwhelming now cause we spent all this money and I've yet to make even one pen. It's very stressful UGH


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## randyrls

Ddw04 said:


> Thanks so much but sadly I do not have a set of drill bits.
> 
> Also what are calipers? In the sense of what your referring I use them for?



You can get a cheap drill bit set from Harbor Freight.  They are cheap though.  When I got my set, I marked the shank each time I used the bit.  after 5 or so marks, I bought a high quality bit of the same size.  Norseman, Chicago-Latrobe, or Cleveland all make high quality bits.  I lucked onto a sale of Chicago-Latrobe bits for under $150 and snapped them up!

Drill bit set for $34 and may be cheaper when on sale.
Calipers for measuring  $10.


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## jttheclockman

Ddw04 said:


> Also since I dont really know how long I'm gonna be doing this stuff I dont want to be buying that many drill bits I may just but a 7mm brand point one every so years.



First lets start with a name. Would be helpful to know who we are talking to. Nice when people join they put their name in the signature section of the profile page or at least sign it at the end of the post. We are a friendly bunch here.

Next is Pen making is not rocket science it is a hobby that can be enjoyed from kids to elderly adults. As far as tools needed, this depends alot on what you already have and how far you want to take this. Tools make the task at hand easier and more enjoyable and yes it can get daunting and somewhat expensive, but tools are bought once. Kits and blanks are bought forever and that is where the expense comes in. Things bought can be sold if you decide to get out of the hobby so think of it as rental. Drill bits are a must in just about all hobby and they are useful around the house for other things too. So a set of drill bits is something you should consider. Harbor freight can get you tools that are yes cheap but will do the job till you decide what it is you want. Turning wood blanks and acrylic blanks can be done with same tools. Finishing the blank takes different techniques. Honing your technique for a good fit and finish is all up to you. We can suggest things but practice will get you there. What you do with the knowledge and ability is in your hands after that. Weather you develop a thirst to sell your work or give it away or donate pens is up to you and you alone. I suggest do not go into this half hearted because you are destined to fail and become frustrated. If serious we are here to help. You will get various answers to questions but that is because there is more than one way to do things and over time you will develop your own method.   

You have been give some good suggestions already about finding a turner to help you learn the techniques of tool usage and possibly finding a Woodcraft store that holds classes for pen turning. There are a ton of utube videos out there and some are informative and some people just like to hear themselves talk and waste time. Learning safe workshop practices is key to a safe environment and joy of the hobby. If it does not feel right it probably isn't. Come here and ask. Learn your tools and what they can do. A good carbide round cutter will get you about 90% of all blanks turned. I stress this all the time because I believe it is the best turning tool around and that is a good quality Skew. But it takes some practice to master. Not much more to tell you but hope you stay with it and learn to enjoy this hobby. Again we all are here for you and any other newbie that wants to learn. Good luck.


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## monophoto

Discussions on this board can wander a bit, and there are lots of people who have different but perfectly valid approaches to dealing with the problems being discussed.  So allow me to circle back to the point where this conversation began.

The original question was what is the appropriate drill bit for a tube that appears to have a 9/32" OD?  

I can see how Ddw04 is confused - 9/32" converts exactly to 7.142mm,  so a hole drilled using a 7mm bit would appear to be too small for the tube.

Out of curiosity, I just made a series of  measurements using digital calipers.    Any time you make measurements you have to worry about three things - precision, accuracy and repeatability.   The digital calipers reported measurements to three decimal places - that's the precision factor.  Unfortunately, my alternate calipers are analog, so while they seem to give the same results, the precision is much less, so I can't absolutely confirm the accuracy of the digital calipers to three decimal places of precision.  The  fact that all three measurements were made using the same calipers and within a few minutes leads me to believe that the repeatability concern has been addressed.   So while these measurements don't meet laboratory standards for accuracy and repeatability, I think that these factors are close enough for this discussion.

So here's what I found:

The 7mm tube supplied with a PSI stylus kit measured 6.750mm OD.  My experience is that there is some slight variation in the OD of nominal 7mm kits.
My 7mm brad point bit (manufacturer unknown) measured 6.900mm OD.  I would not be surprised to see variations between my drill bit and others with the same nominal OD.
A 9/32" bit from a 115 bit Harbor Freight set measured 7.040mm.  Again, slight variations are possible.
Also, drill bits tend to 'wobble' a bit -  the bit can flex, it can be deflected by gradations in hardness within the blank, the mounting in the Jacobs chuck can be slightly off center, etc.  As the flutes of a bit fill with swarf, the swarf can cause the wood fibers around the hole to be compressed a bit.  Also, heat from that swarf rubbing against the walls of the hole expells moisture from the wood fibers and causes them to shrink.  Taken together, this means that a hole drilled in wood can be slightly larger than the actual OD of the drill bit.

So the key to clarifying this apparent mystery is to understand that turning pens isn't rocket science.  The ID of the hole clearly must be larger than the OD of the tube, but how much larger is unknown. If the hole is too small, then the glue that is applied to adhere the tube to the inside of the hole will be expelled when the tube is inserted, and that can cause the glue joint to fail. On the other hand, if the ID of the hole is too large, then glue that is used to adhere the blank to the tube will be challenged to fill a larger gap, and if that gap exceeds the bridging capability of the glue, that can also lead to glue joint failure.

_So here's my advice to Dwd04 - - - if possible,  use a drill bit that matches the recommendations from the kit supplier, and use a good gap-filling glue.  Be sure to scuff up the tube with sandpaper to improve adhesion between the glue and the brass.  The glues that are recommended for this application are thick CA, two-component epoxy, and polyurethane - all three can work well.   If you don't have the exact bit recommended by the kit supplier, you can try a different bit and see whether it works for you.  Failure of the joint between the blank and the tube isn't fatal - you may end up sacrificing a  blank, but you can always clean off the tube and glue it into another blank, and the experience will have taught you something._

_





_


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## TonyL

A separate, but related subject:

there are some excellent videos on sharpening drills with a grinder. I first mad a jig, then I started sharpening by hand and was surprised by the results. I use Norseman bits from Fairbury Fasteners, but i have hand sharpened the black bits that come with PSI starter sets.  I have owed a drill doctor 750x for 3 years and like it, but I got tired of turning that cam thing. I am sure my hand method removes more material and isn't as precise as the DD, but it takes me 4 seconds.  I drill through all materials very cleanly with a freshly sharpened drill.I still can't sharpen my wife's kitchen knives, but somehow I am able to sharpen drills.  Happy drilling!


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## Ddw04

jttheclockman said:


> First lets start with a name. Would be helpful to know who we are talking to. Nice when people join they put their name in the signature section of the profile page or at least sign it at the end of the post. We are a friendly bunch here.
> 
> Next is Pen making is not rocket science it is a hobby that can be enjoyed from kids to elderly adults. As far as tools needed, this depends alot on what you already have and how far you want to take this. Tools make the task at hand easier and more enjoyable and yes it can get daunting and somewhat expensive, but tools are bought once. Kits and blanks are bought forever and that is where the expense comes in. Things bought can be sold if you decide to get out of the hobby so think of it as rental. Drill bits are a must in just about all hobby and they are useful around the house for other things too. So a set of drill bits is something you should consider. Harbor freight can get you tools that are yes cheap but will do the job till you decide what it is you want. Turning wood blanks and acrylic blanks can be done with same tools. Finishing the blank takes different techniques. Honing your technique for a good fit and finish is all up to you. We can suggest things but practice will get you there. What you do with the knowledge and ability is in your hands after that. Weather you develop a thirst to sell your work or give it away or donate pens is up to you and you alone. I suggest do not go into this half hearted because you are destined to fail and become frustrated. If serious we are here to help. You will get various answers to questions but that is because there is more than one way to do things and over time you will develop your own method.
> 
> You have been give some good suggestions already about finding a turner to help you learn the techniques of tool usage and possibly finding a Woodcraft store that holds classes for pen turning. There are a ton of utube videos out there and some are informative and some people just like to hear themselves talk and waste time. Learning safe workshop practices is key to a safe environment and joy of the hobby. If it does not feel right it probably isn't. Come here and ask. Learn your tools and what they can do. A good carbide round cutter will get you about 90% of all blanks turned. I stress this all the time because I believe it is the best turning tool around and that is a good quality Skew. But it takes some practice to master. Not much more to tell you but hope you stay with it and learn to enjoy this hobby. Again we all are here for you and any other newbie that wants to learn. Good luck.


This isnt something I plan to do for like my whole life just every now and again some day I would like to make things like a cereal bowl but that's years a later Haha but nothing too fancy, I know people will suggest different things I was just hoping for like 4 out of like 8 people suggesting the same drill bit or something like that i wasnt expecting everyone to say the same thing


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## jttheclockman

Ddw04 said:


> This isnt something I plan to do for like my whole life just every now and again some day I would like to make things like a cereal bowl but that's years a later Haha but nothing too fancy, I know people will suggest different things I was just hoping for like 4 out of like 8 people suggesting the same drill bit or something like that i wasnt expecting everyone to say the same thing


Because most of us have been there seen that and own the Tee shirt.


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