10.5mm vs Z drill bit?

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ramaroodle

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Does anybody use a Z lettered bit for a 10.5mm hole? I know I bought a 10.5 mm but can't find it but from Rockler they are ridiculous price-wise. I can buy a whole 60 or 115 piece set from HF for stupid cheap.

Z=.413" 10.5mm = .4134 so it's only about 4 thou.
 
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MiteyF

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The size will work fine. But be wary of the cheap HF drill bits. I bought one of the big, cheap sets, thinking they'd be fine for something simple like wood pens. Many are so crooked they're unusable. I have the cheap set in case I REALLY need a certain size, once or twice. If I find myself using that size anything resembling regularly, I just buy a good bit.
 

magpens

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Yes, go ahead and use a "Z". . It is only 0.4 thou smaller in size than a 10.5 mm. . The difference is totally negligible for this purpose.

And, besides, the 10.5 mm drill is only an approximation in the first place. . It is oversize to the brass tube like all recommended drill sizes.
The actual size hole you get depends on the material you are drilling.
The recommended drill size is oversize to allow for that, and also to allow for the glue.
 

ramaroodle

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The size will work fine. But be wary of the cheap HF drill bits. I bought one of the big, cheap sets, thinking they'd be fine for something simple like wood pens. Many are so crooked they're unusable. I have the cheap set in case I REALLY need a certain size, once or twice. If I find myself using that size anything resembling regularly, I just buy a good bit.
Thanks. I know exactly what you mean but I bought a good 10.5 from Rockler. Can't find it and can't bring myself to spend another $10 on one bit especially when I know I have one here somewhere and know I'll find it right after I buy another one. I have a HF set but not the one with lettered bits and the 25/64 is too small and a pain to enlarge.
 

its_virgil

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Does anybody use a Z lettered bit for a 10.5mm hole? I know I bought a 10.5 mm but can't find it but from Rockler they are ridiculous price-wise. I can buy a whole 60 or 115 piece set from HF for stupid cheap.

Z=.413" 10.5mm = .4134 so it's only about 4 thou.
Rockler and Woodcraft are not the best place to purchase drill bits. You just mentioned why.

I actually have the more expensive HF set snd find them quite reliable.

Find an industrial supply and shop for drill bits.

Do a good turn daily!
Don
 

eharri446

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Check out Drills and Cutters and VictorNet. They both sell drill bits, however, there is a minimum purchase amount with Drills and Cutters. I believe that it is $25.
 

ramaroodle

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Rockler and Woodcraft are not the best place to purchase drill bits. You just mentioned why.

I actually have the more expensive HF set snd find them quite reliable.

Find an industrial supply and shop for drill bits.

Do a good turn daily!
Don
Yeah but I'm not doing production work. I can get 115 HSS bits that I can sharpen for $39 minus 20% that'll last for years. I'm good with that. I have too many of those expensive Rockler bits mainly cuz they were an odd size I didn't have and they were handy. Those days are over. Now I check for odd size bits before I buy a kit.
 
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Curly

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Z=.413" 10.5mm = .4134 so it's only about 4 thou.

I have to correct you for educational reasons or I'll go nuts. 🤪

10.5mm = .4134 is actually 4 ten thousandths of an inch different from the Z = .413. Roughly one tenth the thickness of a sheet of copy paper if it helps you visualize it.

.x is tenths of an inch.
.xx is hundredths of an inch.
.xxx is thousandths of an inch.
.xxxx is ten thousandths of an inch. You'll rarely run into anything in woodworking where this would matter.
.xxxxx is hundred thousandths of an inch. In over 27 years of inspecting aircraft structural parts I never ran into anything with tolerances this small. We didn't have the climate control or tools that could measure it much less make it either. ;)

There I feel better. 😊
 

Edgar

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I have to correct you for educational reasons or I'll go nuts. 🤪

10.5mm = .4134 is actually 4 ten thousandths of an inch different from the Z = .413. Roughly one tenth the thickness of a sheet of copy paper if it helps you visualize it.

.x is tenths of an inch.
.xx is hundredths of an inch.
.xxx is thousandths of an inch.
.xxxx is ten thousandths of an inch. You'll rarely run into anything in woodworking where this would matter.
.xxxxx is hundred thousandths of an inch. In over 27 years of inspecting aircraft structural parts I never ran into anything with tolerances this small. We didn't have the climate control or tools that could measure it much less make it either. ;)

There I feel better. 😊
Spoken like a true metrologist. 😊

Well said, Curly. I often get into debates about such things.
 

KenB259

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Does anybody use a Z lettered bit for a 10.5mm hole? I know I bought a 10.5 mm but can't find it but from Rockler they are ridiculous price-wise. I can buy a whole 60 or 115 piece set from HF for stupid cheap.

Z=.413" 10.5mm = .4134 so it's only about 4 thou.

I too fell for the cheap harbor freight cheap drill bit set. Most are not even straight. A full bit, I can deal with, easily sharpened. One that doesn't run true, is if no use to me. I bought a good set of Norseman's and could not be happier with them.


Sent from my iPhone using Penturners.org mobile app
 

magpens

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I agree with Ken .... don't go cheap on the drills. . If you do, it's inviting frustration.

Norseman Brand drills have served me well, and I highly recommend them also ... SAE, Metric, and Letter sizes, as well as Number sizes.

Some tool stores will sell individual sizes, so that you don't have to buy a whole set. . But I have never been sorry I bought complete sets.
 

greenacres2

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Went from Drill America to Norseman a few months ago in imperial--unbelievable difference. Picked up Viking in metric by 0.5 mm (couldn't find Norseman in metric jobber)--one of the best improvements i have made.
earl
 
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