Bullet point/pilot point drills?

[Skin-Job]

I use DeWalt bullet point drills and like them a lot. I find they don't wander as easily and tend not to chip out the bottom as much.
I would like to use them for my new foray into turning pens.
I'm having trouble finding the difinitive drill set for pen turning. Metric sizes seem to be an issue.

Does anyone use this type of drill bit, and which sizes do they find most useful for pen making?

Many thanks,

Karl

 

[Bigblackdog]

I think that you need to start with a kit and work out the drill options from that. I have a useful set of 6-10mm in 0.1mm increments from uk drills, but other than that I have to buy single drills for the tubes. There isn't a set as such for pen turning, and you will probably be lucky if you can get the sizes you need in the dewalt drills- most that I use are oddball sizes.

 

[Neil Lawton]

I think Walter Hall has bullet points, but I think he bought his imperial sizes from the USA

 

[Phil Dart]

What Mark said, Karl. Pen kits use very peculiar drill sizes sometimes. Several of them are metric, but they are usually down to tenths of a millimeter, and others use imperial sizes. 15/32, 27/64, 25/64 and 23/64 are not uncommon. I have just turned a kit that needed a 9/16 drill - ouch, that hurt my wallet quite a bit. I would suggest that you build up your drill bit collection as and when you decide to try out a new kit, rather thann trying to second guess what you might need in advance. If the kit retailer is half descent, they will generally carry the appropriate drill bits to support their kits, and if they don't you can draw your own conclusions about the desirability of either the retailer or the kit.

 

[Neil Lawton]

What Mark said, Karl. Pen kits use very peculiar drill sizes sometimes. Several of them are metric, but they are usually down to tenths of a millimeter,

Really?
Or thousands of an Inch?
I would be interested to see a list of purely metric kits Phil. Please don't take this the wrong way but surely anything off the whole base 10 was not originally metric? Why would you make stuff 12.5mm and say half of that figure is 6.35 then add "nominal" to make up the difference?

 

[Skin-Job]

I think it's probably sound advice to build up drills as I go.
I like 'sets' of things, and really like the way bullet/pilot points cut.

 

[Phil Dart]

Really?
Or thousands of an Inch?
I would be interested to see a list of purely metric kits Phil. Please don't take this the wrong way but surely anything off the whole base 10 was not originally metric? Why would you make stuff 12.5mm and say half of that figure is 6.35 then add "nominal" to make up the difference?

I understand what you're saying, but the reality is that if you are designing a pen kit, you have component diameters in mind, and you also have to take into account the need to compress tenons into a tube, allow for other bits and bobs to be inserted or removed, like ink converters and refills, plus you have to make an allowance for the fact that one or two people might need a bit of space to cover the tube with something nice to turn on a lathe.

So you do all that, and end up with a tube size, which granted you can tweak a bit then adjust all the sizings all the way through. But then you need some space for some glue as well, so you end up with a drill size that does not necessarily conform to a Screwfix jobber set.

 

[Neil Lawton]

I understand what you're saying, but the reality is that if you are designing a pen kit, you have component diameters in mind, and you also have to take into account the need to compress tenons into a tube, allow for other bits and bobs to be inserted or removed, like ink converters and refills, plus you have to make an allowance for the fact that one or two people might need a bit of space to cover the tube with something nice to turn on a lathe.

So you do all that, and end up with a tube size, which granted you can tweak a bit then adjust all the sizings all the way through. But then you need some space for some glue as well, so you end up with a drill size that does not necessarily conform to a Screwfix jobber set.

So why does the drill diameter usually always equate to an Imperial size? Why not make all outside diameters Metric and not bother the kit maker with odd sizes on the internals? In most cases nobody would want to know, or care, if the kit worked?
I think it is fair to say that most things supplied in ridiculous Metric sizes are because they are manufactured in Imperial (8 x 4') for example. Most 3mm metal sheet is 3.2! The reality is that most heavy manufacturing is either done on outdated British Imperial machinery or is made in the Far East to American specification.

 

[Phil Dart]

You would be right, but for the fact that with regard to pens, you have it the wrong way round. The ridiculous imperial sizes exist because one upon a time the Americans used to dominate the market. The ridiculous metric sizes exist not because they are approximate equivalents but because now tubes are routinely made in metric sizes. However, come what may there is still a need for glue space.

If your tube has a physical o/d of say 10mm, what drill size do you use? If you have a screwfix set you might be tempted to use a 10.5, which will be far too big. So you end up with a need for something like a 10.2 or 10.3, and so it goes on.

The rule of thumb is though, as you well know Neil, that there are no hard and fast rules. If a kit manufacturer recommends a drill of a certain size and you think you can get away with something you already own that is close in size, then go for it. But I think it is right that a pen kit designer should not have to compromise his design simply to conform to the drills you can buy in B&Q.

 

[Walter]

The reality is that most heavy manufacturing is either done on outdated British Imperial machinery or is made in the Far East to American specification.

I think you hit the nail on the head there. Most kits are manufactured for the American market.

As for the De Walt bullet point bits I have a set of metric which I bought from Screwfix DeWalt Extreme 2 HSS Drill Bit Set 29Pc | HSS Drill Bit Sets | Screwfix.com

and a set of Imperial that I had to import from the USA. DEWALT 29-Piece Pilot Point and Drill Bit Set DW1969 | eBay

I have yet to come across a kit that cannot be accommodated by one or other of those sets.

 

[Penpal]

I use preferentially DeWalt Extreme 2 Drills,I get many hundreds of blanks from the 7mm size.

I enclose a pic of one drill. The rub over here is metric is easy to get imperial difficult. When I built my huge carport out system out front the drill point large drills were invaluable up a ladder for drilling 3/8 wall thickness 6 inch pipe. I thread cut for 3/4 inch stainless
bolts. The drill point does not skid on rounded surfaces, they do not track down the grain sideways and I rarely ever have a blowout.

Peter.

 

[clement]

I use them for a couple of months now, very satisfied. In Belgium we have them only in metric size ! I use 10.5 mm, 11.5 mm and 12.5 mm mostly

 

[Skin-Job]

That's really great information.
Thank you.

Karl

 

[wm460]

Another vote for DeWalt Extreme 2 Drills.

 

[Skin-Job]

Picked up the 29 bit Metric set from Screwfix today, and have the Imperial set on the way from the US.

Many thanks for all the advice and input.
Much appreciated, having this resource for the beginner. It really saves a lot of time and hassle having the experience of the members here.

K