7mm step drill bit

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abearpens

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Jan 22, 2006
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Hurst, texas, USA.
Hello all, I am looking for a 7mm step drill bit for some occasional slimline pen one offs that I do custom. Can't find a good supplier. I don't really want to grind one on my metal lathe.
 
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dogcatcher

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Jul 4, 2007
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TX, NM or on the road
Not a source, but a solution. I would drill part way with the 7mm and flip the blank and drill the small hole from the other end. I would first turn my blank to 3/4 diameter and use my collet chuck to hold it while drilling. It is the way I make my Pentil pencil conversions without a step bit.
 

magpens

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Canada
What size would the smaller step be ? About 0.12" or so ? Just big enough to let the refill tip pass through ?
 

PenPal

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Nov 29, 2006
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Canberra, A.C.T., Australia.
This is my step drill AKA reamer sold to me in the 80,s (all you could buy those days for7mm pens I treat this like gold,I face off on a 12 inch sander and this drill is still a snug fit in the blank and as you can see from the four blanks it lightly reams the hole and cleans it thoroughly.. If you find a firm capable of grinding one from a HS Reamer please share with me. Also see some of the terms used by Pro Firms this one claimed within a fraction of a mm of measure in the US but failed miserably.I negotiated by phone with the owner of Fuller even got an IAP member to deliver a Slimline brass or three for a go no go guage.

Peter.
 

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magpens

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Peter,

You always have such helpful contributions !! . Thank you again !!!
 

scubaman

Passed Away Jun 20, 2018
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Wappingers Falls. NY
Suggestion: Do it in 2 operations. First drill your 7mm to the desired depth, then follow up with a small-drill that you epoxy into a piece of drill-rod of the same diameter (or a couple of thousandths less if you find it's too tight). (The first drilled hole's exact diameter depends on a lot of parameters like speed, feed rate, etc and the specific material)

That way you can be ASSURED that the 2 holes are concentric. If you drill from 2 sides, no matter how careful you are, you'll lose some (in my experience :))
 

Mr Vic

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Aug 11, 2008
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Falcon, CO
Try a search on Pental converion. Can't remember the vendor but they sell a long 7mm drill stebbed don on the end s well as a mandrel thatis stepped down. Will try to look for it tomorrow.
 

randyrls

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Feb 2, 2006
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Harrisburg, PA 17112
Rich (scubaman) is correct; Get a piece of steel rod, pick the size of the pilot drill bit and use it to drill the end of the rod while holding the rod in your lathe chuck. Then reverse the bit and Loctite / Epoxy the drill bit into the end of the rod. Done.
 
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