Pen Blank Dimensions

JPG · Post by **JPG** » Tue Dec 22, 2009 12:11 pm

I am considering cutting up some of my Black Walnut scraps into pen blanks for an acquaintance who turns pens. I thought I would 'octagonalize' them for him.

My question is what size? ?/? x ?/? x ? The finish diameter seems to me to be about 3/8". So is 1/2" x 1/2" x 3" adequate?

curiousgeorge · Post by **curiousgeorge** » Tue Dec 22, 2009 12:38 pm

The length would be determined by the type of pen kit, but 1/2x1/2x3 would probably work for most kits. Why not ask you acquaintance what would work best for him?

tom_k/mo · Post by **tom_k/mo** » Tue Dec 22, 2009 12:42 pm

JPG, most blanks you buy are 3/4" x 3/4" x 5 or 5-1/2" long You COULD get by with 1/2" square stock, but it makes drilling the center hole much more critical. Also, 3" long blanks may work OK for a single tube pen, such as a Gadsby, but on pens with 2 tubes, you'd want to have a 5 or 5-1/2" long blank and cut the pieces in half yourself so that the grain matches on the top and bottom half.

JPG · Post by **JPG** » Tue Dec 22, 2009 1:16 pm

curiousgeorge wrote:The length would be determined by the type of pen kit, but 1/2x1/2x3 would probably work for most kits. Why not ask you acquaintance what would work best for him?

Now what kind of surprise would that be?

Thanks Tom. I have 1/2" scraps. That was why I 'suggested' 1/2". Would it be helpful if I drilled a pilot hole in each end?

I could offer to drill them for him(if he loans me the proper bit if required) after he accepts them.

tom_k/mo · Post by **tom_k/mo** » Tue Dec 22, 2009 1:24 pm

JPG40504 wrote:Would it be helpful if I drilled a pilot hole in each end?

I could offer to drill them for him(if he loans me the proper bit if required) after he accepts them.

JPG, Depends upon what kind of pen(s) he's turning. I've got pen styles that use 7mm, 8mm, 10mm, 27/64" (10.5mm) and an "O" drill. You could drill a 7mm hole and he could enlarge it if he wanted, but... all the drill bits I've purchased for drilling blanks have been brad point bits, not normal twist point. A normal twist point would center itself in the pilot hole and he could enlarge it rather easily if required, but brad-point bits don't easily follow a pilot hole. I'd ask him.

EDIT: I just got my digital calipers out and checked a couple of my pen styles. The Designer/Euro pen style the largest bushing diameter is 33/64". The Parker Classicpen style, the cap diameter of that pen is 17/32" A 1/2" square blank wouldn't work for these style pens. They would work fine for Slimline pens though.

curiousgeorge · Post by **curiousgeorge** » Tue Dec 22, 2009 3:22 pm

JPG40504 wrote:Now what kind of surprise would that be?

Thanks Tom. I have 1/2" scraps. That was why I 'suggested' 1/2". Would it be helpful if I drilled a pilot hole in each end?

I could offer to drill them for him(if he loans me the proper bit if required) after he accepts them.

Sorry! You said nothing about it being a surprise....

fjimp · Post by **fjimp** » Tue Dec 22, 2009 4:48 pm

Saturday I squared several pen blanks. I received a nasty surprise on one blank that was just over 1/2" diameter. It seems there was a crack in the blank. I did not show up when drilled or when the tubes were inserted. However when I attempted to square it up prior to turning it literally split in half. Now I am aware this sort of thing can happen yet on a 3/4 inch blank I noticed a potential crack after squaring it. On this blank I used CA glue to stabilize the blank prior to turning. I can still see the crack after turning yet the burl of this maple blank makes it pretty enough that I planned to keep it for my own use. A neighbor picked it up and fell in love with it. Even after being warned of the flaw still wanted it. He shows the pen off everyplace he goes. Had that blank been 1/2 inch I doubt seriously it would have survived the squaring process much less turning. Incidentally I never sell the pens I turn, all are gifted to the recipient. So if that pretty burl breaks the price was still right. Jim

paul269 · Post by **paul269** » Tue Dec 22, 2009 5:26 pm

tom_k/mo wrote:JPG, Depends upon what kind of pen(s) he's turning. I've got pen styles that use 7mm, 8mm, 10mm, 27/64" (10.5mm) and an "O" drill.

The O bit is 8mm. A J bit is 7mm.
ga. in. mm

A 0.234 5.944
B 0.238 6.045
C 0.242 6.147
D 0.246 6.248
E 0.250 6.350
F 0.257 6.528
G 0.261 6.629
H 0.266 6.756
I 0.272 6.909
J 0.277 7.036
K 0.281 7.137
L 0.290 7.366
M 0.295 7.493
N 0.302 7.671
O 0.316 8.026
P 0.323 8.204
Q 0.332 8.433
R 0.339 8.611
S 0.348 8.839
T 0.358 9.093
U 0.368 9.347
V 0.377 9.576
W 0.386 9.804
X 0.397 10.08
Y 0.404 10.26
Z 0.413 10.49