# Drill bits



## theoldwizard1 (Aug 13, 2014)

So clearly a set on fractional drill bit is a requirement.  Amy recommendations in this would be apprciated.

My real question is for tapping metal, which are more important, letter or number drills ?


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## drs23 (Aug 13, 2014)

theoldwizard1 said:


> So clearly a set on fractional drill bit is a requirement.  Amy recommendations in this would be apprciated.
> 
> My real question is for tapping metal, which are more important, letter or number drills ?



Easy answer. All three. Just missed a good deal on a group buy for bits from Goodman. I really use mine alot now that I have them.


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## pineyfolks (Aug 13, 2014)

Buy the fractional set to start with. There are some that are common tap drill sizes in there. Buy the other ones as you need them and just store them with the tap they are for. Eventually you'll have them all.


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## JimDawson (Aug 13, 2014)

I would buy the HF 115 piece set.  That way you get all of the sizes, and it's cheap.  I keep several sets around, I buy them when I have a 20% off coupon.  As you break them, just replace them with better quality bits.  They actually work pretty well, except the grind on some of them may be wrong, but sharping drill bits is easy, and a necessary skill for the hobby machinist.


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## BigLar368 (Aug 13, 2014)

I bought a Harbor Freight cobalt set. I think it's the 115 bit set. They stay pretty sharp and are a good value for the price you pay.


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## kizmit99 (Aug 13, 2014)

BigLar368 said:


> I bought a Harbor Freight cobalt set. I think it's the 115 bit set. They stay pretty sharp and are a good value for the price you pay.



I have to agree, the HF Cobalt 115 bit set is an awesome way of getting an at least semi-decent complete set of fractional, numbered and lettered bits.  I only wish they had a similar set of metric bits.  If you get the HF set be careful though, my set was missing the 5/16 bit and instead had two 17/64 bits - didn't figure that out until a 5/16 bolt wouldn't fit in the supposedly 5/16 hole


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## jpfabricator (Aug 13, 2014)

kizmit99 said:


> I have to agree, the HF Cobalt 115 bit set is an awesome way of getting an at least semi-decent complete set of fractional, numbered and lettered bits.  I only wish they had a similar set of metric bits.  If you get the HF set be careful though, my set was missing the 5/16 bit and instead had two 17/64 bits - didn't figure that out until a 5/16 bolt wouldn't fit in the supposedly 5/16 hole



Someone overseas has a sick sense of humor!
Hes probably still snickering.

Jake Parker


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## Andre (Aug 14, 2014)

I'm spoiled and use mostly HOUT twist drills. But they are a "luxury" (I say that from a hobby machinist perspective) and I'm sure HF drill bits work just fine if you know how to sharpen them. And when/if they break, make punches out of them.


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## darkzero (Aug 14, 2014)

I would definitely start off with a 29 pc fractional set if limited on funds. I'm not a big fan of the TiN coated drills though, I prefer black oxide & cobalt. I do still have my TiN set but I don't care for them much & abuse them sometimes.

I also have a 115 cobalt set from HF. For the price & 25% off it's a worthy buy. The drill index it comes with is junk though, i tossed it out & replaced it with a Huot 115 index.


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## theoldwizard1 (Aug 14, 2014)

darkzero said:


> I also have a 115 cobalt set from HF. For the price & 25% off it's a worthy buy. The drill index it comes with is junk though, i tossed it out & replaced it with a Huot 115 index.


Huot get my vote for the best index also !


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## mattthemuppet2 (Aug 14, 2014)

I really cheaped out and bought one of the HF 29pc TiN fractional sets, as I couldn't (can't) afford one of the full 115pc sets. It's okay - a few of the drills aren't straight, so cut oversize by a bit, others had uneven grinds and some have broken, which I've replaced by 135deg split point cobalt drills. Those are world above the 118deg point drills in the cheap set - start more easily and without a pilot hole, don't wander and cut straighter. I've reground a couple of the HF bits and as I use them now I'm taking the burrs off and honing each one on my arkansas stones, which seems to make a big difference.

For $10 I really can't complain and given the financial circumstances, I'd do the same again. I'm just looking forward to the time when I can afford a decent 135deg split point set 

As for getting the right drill for a tap, there's usually enough wiggle room with thread depth that I just hold the drill in front of the tap and see which one works the best. For the stuff I do (mostly alu), I can get away with that.


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## Kevinb71 (Aug 14, 2014)

"Someone overseas has a sick sense of humor!
 Hes probably still snickering.

 Jake Parker "


It's like the old cartoon of two guys in a warehouse. One says to the other "Just ship'em the one in the bin next to it. By the time they get it we'll have the right one back in stock."


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## xalky (Aug 14, 2014)

I had one of those harbor freight sets. I use it for drilling wood now. I had the 1/4" bit untwist when it caught at the end of the hole while drilling a piece of 3/8" steel. I was laughing my ass off when it happened. I'd never seen a drill bit do that in my life. Soft steel, and barely case hardened.


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## mattthemuppet2 (Aug 14, 2014)

yeah, it's not great (my 1/4 broke too ) and the tips chip more easily than they should, but it'll do until I can afford something better or have replaced all the more useful ones! Considering a half decent 29pc fractional set is ~$60 and double that for a US set, it's pretty good value at $10.


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## JPMacG (Aug 14, 2014)

I've had good luck with a TiN set from Grizzly.   It is the full 115 piece numbered, lettered and fractional set. In hindsight that was the right thing to do.


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## Shadowdog500 (Aug 17, 2014)

+1 on the HF cobolt set.  They really work well for me.  I also have a couple of the less expensive HF set for non critical stuff.  

Welcome oldwizzard1!  You the same old wizzard from the GJ?

Chris


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## theoldwizard1 (Aug 18, 2014)

Shadowdog500 said:


> +1 on the HF cobolt set.  They really work well for me.  I also have a couple of the less expensive HF set for non critical stuff.
> 
> Welcome oldwizzard1!  You the same old wizzard from the GJ?
> 
> Chris


One and only TOW !


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## stupoty (Aug 18, 2014)

JimDawson said:


> I would buy the HF 115 piece set.  That way you get all of the sizes, and it's cheap.  I keep several sets around, I buy them when I have a 20% off coupon.  As you break them, just replace them with better quality bits.  They actually work pretty well, except the grind on some of them may be wrong, but sharping drill bits is easy, and a necessary skill for the hobby machinist.



I tend to do that too, a compleat set is very handy and the most used ones get upgraded with quality brands or duplicates.

stuart


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## visenfile (Aug 25, 2014)

Always curious about other countries...At HF I got a set of cobalt drills years ago in a metal stand-made in Russia.  Excellent to this day.  It is interesting to get decent product from the "other" countries who have to have them to produce e.g. space related.  When will the Chinese start offering their better machine tools?  

For many years I have had to cheat on drill diameters for tapping.  Yes, holding up the target bolt to the drill shank will probably get you there. Better is to look up the proper drill callout and use the decimal to mike your available drills.  I always go slightly undersize to assure full thread formation, but tap breakage is possible .  Use lots of lubricant. A trick I use to achieve perpindicularily is to chuck up the tap in your drill press and place the work piece in a vise. Hand turn the tap (of course it's hard) while using slight downward feed lever.  Go slow and back off every 1/4 turn to dislodge chips.  Try to get at least one full turn .  Transfer the workpiece to a vise and carefully start the tap, letting it index in the thread.  Works for me.  Takes some practice.  To gain some leverage during the hand turn I engage the chuck wrench which gives some purchase.  Die work is trickier with limited tools. I have (in desperation) hand ground rod to an approximate od and used a die.  This was on some very rough automotive tooling. (no lathe).  Do not retch-remember this is the beginners' forum.)


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## theoldwizard1 (Aug 26, 2014)

visenfile said:


> Always curious about other countries...At HF I got a set of cobalt drills years ago in a metal stand-made in Russia.  Excellent to this day.  It is interesting to get decent product from the "other" countries who have to have them to produce e.g. space related.  When will the Chinese start offering their better machine tools?


I have wondered the same !

In the past and very generalized, I find that product specifically from Taiwan are better quality than those that simply say "Made in China".  Example : I have a set of Neiko drills, HSS with TiN coating that have held up well over the years.


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## theoldwizard1 (Aug 26, 2014)

visenfile said:


> A trick I use to achieve perpindicularily is to chuck up the tap in your drill press and place the work piece in a vise. Hand turn the tap (of course it's hard) while using slight downward feed lever.  Go slow and back off every 1/4 turn to dislodge chips.  Try to get at least one full turn .  Transfer the workpiece to a vise and carefully start the tap, letting it index in the thread.  Works for me.  Takes some practice.  To gain some leverage during the hand turn I engage the chuck wrench which gives some purchase.


I found these device by accident.  They are now on my "wish list" !

*Big Gator Drill and Tap Guides* _(Clamping not required for tap guide)

_


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## 6530 (Aug 26, 2014)

Very slick.  Looks like Amazon carries them.  LMS too.

http://www.amazon.com/gp/aw/d/B000ZN30U4?pc_redir=1408721808&robot_redir=1

http://littlemachineshop.com/products/product_search.php?critFast=big+gator+tools

http://www.biggatortools.com/suppliers.html


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## Ebel440 (Sep 1, 2014)

To start a tap straight you can also drill the hole to the fastener size to act as a guide. This only works if th  part is thick enough to sacrifice some material or you can get to the back of the hole.  For instance if your tapping a 1/4-20 thread an inch deep drill to .204 then drill down .150 or so with a .250 drill and that helps start the tap straight.


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## visenfile (Sep 1, 2014)

Back to holes...Some hand drills have spirit bubbles for x-y which should help.  I have even used 90 degree squares as "sight lines" in the background  while hand drilling.  This alignment becomes a real problem in e.g., wood door panels, or rectangular tubing that must be drilled free hand.  Bummer when the bolt heads and nuts will not snuggle properly.  

Creating threaded shafts  with limited tools is very difficult.  I have had some success with the drill press alignment stated above.  Extending threads on a thick shank bolt is not so difficult (but threads are weaker), but does not work on  rolled thread bolts where the shank od does not support a proper thread depth.  That tool above looks very good, and expensive (tool steel?).

Edit. Rummaged and found a handy, low cost drill jig bought years ago at H Frt . Not in the same class as shown above, but handy.  Not at H Frt now, but at Amazon and Rockler. It is a plastic base with 6 slip in bushings.


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