lost drill bit

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jvsank

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I lost my 7mm drill bit when I moved looked everywhere can't be found is there any standard bits that I can use that would work on a slimline pen must have it made by friday. I am ordering one too but don't think it will get here in time.
 
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FYI, the 9/32" bit is .2812" vs the 7mm bit that is .2756". You will want to use thick CA for the tube, or (and I prefer)Gorilla Glue. GG expands greatly to take up the gap, but it does take some time to set up. I let mine sit overnight. Also, as the GG expands, it can cause the tube to slide out. You can check the blank and push the tube back in every 1/2 hour or so for the 1st couple hours, or use a rubber band stretched over the blank lengthwise to keep the tube from sliding out. I do the rubber band and haven't had a problem with that.
I always use a 9/32" bit unless I am turning a custom centerband, then I use the 7mm bit for a bit tighter fit over the transmission.
 
9/32" is recommended by a lot of people as an alternative; but produces too sloppy a fit for my taste. If you have access to letter drills, an "I" or a "J" bit will give you a much better fit than a 9/32".
 
You know, why would anyone think an "I" or a "J" bit is standard if a 7 mm isn't? As for choice of glue, I use whatever is handy and many times don't even bother glueing the tubes in. Why would I when 1) the brass tube expands when a part is pressed into it and 2) the components lock against the wood (or plastic) and tube. To each his own, I suppose.
 
Wouldn't that create a milling problem?, I'm picturing the tube coming out the other end when you mill it.
 
If you go here http://penventory.com and scroll down. There is a drill bit cheat program. It's not perfect, but it works very well. This is what I came up with for 7mm cheat.
I (0.2720) (--0.0036)
7mm (0.2756) <--- Trying to match this one!
J (0.2770) (+0.0014)
 
Originally posted by DCBluesman
<br />You know, <b>why would anyone think an "I" or a "J" bit is standard if a 7 mm isn't?</b> As for choice of glue, I use whatever is handy and many times don't even bother glueing the tubes in. Why would I when 1) <b>the brass tube expands when a part is pressed into it</b> and 2) the components lock against the wood (or plastic) and tube. To each his own, I suppose.
Click to expand...

One of the most commonly recommended tools on this forum is the 115 Harbor Freight drill bit set. That set contains fractional bits, letter bits and wire gauge bits......but NOT metric bits. I guess "standard" depends upon who is writing the definition.

The 7mm tubes that I have, have an OD of 0.266". A 9/32" drill bit is going to give you a hole around 0.281". If anyone thinks their tubes are going to expand by 0.015" when the hardware is pressed into them, they need to get out their calipers and do some measuring. You are going to be quite surprised!!!
 
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