# What makes drill bit sets different?



## Bill Kahn (Aug 12, 2017)

Beginner's question...
I have a cheap 115 piece HSS drill bit set.  Works fine on softer materials.  But there are steels it does not work on.  (I do not know how to evaluate steel--but I am working on old railroad spikes now.  Carbide end mill works on it.  My cheaper HSS end mills do not.)
My drills bits do not drill the railroad spikes.
So, how do I figure out what drill bit set to buy that can work on such harder steel?
I look at HF say and see https://t.harborfreight.com/115-pc-...886.html?utm_referrer=https://www.google.com/ for $110.  (Yeah 20% coupon is available).
But also I see https://t.harborfreight.com/115-pc-...620.html?utm_referrer=https://www.google.com/ for $40.  There must be a real difference.  How can I tell what each can drill?  And how about http://littlemachineshop.com/products/product_view.php?ProductID=3418&category=-456343308 for $500.  So, how is that different?

And for $945 https://www.amazon.com/Cleveland-C7...83604&sr=1-1&keywords=115+piece+drill+bit+set 

Are there carbide sets too?

So, I need to select length (Jobber seems good for my PM25 mill).  
I need to select tip angle (why 118 and why 135?)
I need to select material/brand/grade.  How does one make this selection?

And, in particular, if I want to drill holes in hard steel what should I buy?  (I have given up on drilling into ball bearings.  But as my carbide end mill does well on the rail road spikes that suggests it is doable.)

Drill bit selection must have been covered before.  Any pointer to some such old thread much appreciated--my search did not turn anything up.

-Bill


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## RJSakowski (Aug 12, 2017)

Cheap drill bit sets are sometimes not HSS even if they say they are.  Beyond that, a properly hardened drill bit has to go through a proper heat treating, not always the case with cheap drill sets.
IMO, buying cheap drills is always a crap shoot.  You may get lucky and actually get a set with reasonable steel but chances are good that you won't.  Even if the steel is good, the sets may have mislabeled drills, drills that are bent or drills with an improperly ground cutting edge.  They will usually work on wood, and some times on soft metal but often fail when drilling harder materials.

The best bet is to buy name brand drills.  This can set you back a bit though.  I have had good luck with Interstate drills from Enco, now MSC.  Big box DIY drills can be poor quality unless you get a name brand.  For a general purpose set, I would get the jobber drill set.  screw machine drills or spotting drills can be useful, as can aircraft drills.

As to the tip angle, I have seen the 135º tip on split point drills.  118º is the classic angle for drilling metal.


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## Charles Spencer (Aug 12, 2017)

This place has a wealth of information on drill bits 

http://www.wlfuller.com/


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## Old junk (Aug 12, 2017)

This may sound harsh but do yourself a favor and don't waste your money at hf.the time alone you will waste trying to use those bits can be spent making your projects.it seems expensive when your looking at that China tool flyer compared to some quality tools but when you want to get something done I can't put a price on it.said it before good tools ain't cheap,cheap tools ain't good.


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## T Bredehoft (Aug 12, 2017)

I must admit that I do own each of the three sets of drills. I bought the boxes (three of them) then filled them slowly at work. (as I needed a drill I'd get it from the crib until I had most then I took the box to the crib and filled them. Now I buy the bits I need individually in lots of 3 or 6. I find that the ones I need I use up, the others just sit there waiting their turn.


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## Desolus (Aug 12, 2017)

I buy strictly American manufacture M42 drills. M42 can come in 8% cobalt up to 10% they slice through stuff like crazy and are very very hard and very very heat resistant...


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## Desolus (Aug 12, 2017)

I just looked at the sets you linked, the more expensive ones are M42... a note about M42, because of its hardness, it may shatter and inbed it's self in your eyeball if you use it in a non rigid setup like a cordless drill...

So for drilling things like work hardened stainless steel, M42... and plunge agressively.


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## mikey (Aug 12, 2017)

Bill, may I ask what you're doing with railroad spikes - just curious. 

You will find that 118 degree drills are the most common twist drills and therefore can be found for the lowest prices. Typically, 118 degree drills are for softer materials like mild steels, brass, aluminum and plastics. 135 degree drills are better for harder materials or materials that work harden. Materials like stainless steels usually drill easier with 135 split points because the flatter included angle contacts the work more readily and the drill presumably cuts faster and cooler. I have drills with both point angles and use my 118 points most of the time.

For hard materials, I use cobalt drills. They hold an edge better under the higher heat conditions encountered when drilling harder materials. Cobalt drills will cost more because the material costs more but if you drill hard materials often then it is worth the cost. 

If you have the money and frequently drill high carbon steels, then a 140 degree carbide drill might be what you're looking for. Big bucks, though.

You have a smaller, low power, light benchtop mill. If I were you, I would consider a 118 degree point HSS screw machine drill set from a good maker. Precision Twist Drill, Triumph, Cleveland all make good drills. You can also buy wire size, fractional and letter sets instead of buying a whole 115 piece set at once. Jobber drills are okay but tend to be longer and chew up more space in Z. Screw machine drills are shorter, stiffer and take up less room on Z. Buying cheap drills is not worth the time and money; buy good drills. 

I also suggest you buy a 120 degree spotting drill for use with the 118 degree drill sets or a 140 degree spotting drills if you use 135 degree drills.


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## Bill Kahn (Aug 13, 2017)

mikey said:


> Bill, may I ask what you're doing with railroad spikes - just curious.



I bought a cheap angle plate (from JTS) as I am making plans to do some angle drilling on the PM25.  The angle plate has T-channels.  Very nice.  But, the slots are smaller than on the mill.  So the mill's t-nuts don't fit.  

How hard can making a t-nut be?

I had these old rusted spikes found along an abandoned railroad.  Hey--free material to turn into chips.  After ruining a $20 HSS end mill on them I found that a $100 carbide end mill worked and lo and behold I have the T-cross section cut out.  Slides nicely in the slots.  So, next step is to drill some #7 holes every 3/4" and tap them (for 1/4-20)  (And then bandsaw and finish the ends.  Easy.). Surprise.  My drill bits do nothing.  Ruin a 3/16" HSS end mill.  So, next step is ask smart guys (this list) what to do.  I guess I could have bought a nice set of t-nuts, but, this is a hobby.  All about the journey.  

I am learning a lot about material. I think I was attracted to all this for the geometry.  But turns out materials are interesting too.

Maybe my best path is to avoid hard materials.  Figure out what is soft steel and stay with that.  At least while I am a beginner. But I seem to like the challenges.  (Though drilling ball bearings I did give up on.)

-Bill


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## mikey (Aug 13, 2017)

Funny but the longer I'm in this hobby, the more I find myself buying things that I can easily make but that are cheaper to just buy. For me, T-nuts would fall into that category but when I started out, I tried to make everything myself just to learn how to do it so I get it. I would suggest you try it on mild steel, though!


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## JimDawson (Aug 13, 2017)

The Harbor Freight cobalt drill set seems to be pretty decent.  I have no idea what the RR spikes are made of.  I have a few out in the shop so I'm going to have to try machining one.  I'm guessing cutting at around 50 FPM would work with HSS.


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## DaveInMi (Aug 13, 2017)

Bill Kahn said:


> I bought a cheap angle plate (from JTS) as I am making plans to do some angle drilling on the PM25.  The angle plate has T-channels.  Very nice.  But, the slots are smaller than on the mill.  So the mill's t-nuts don't fit.
> 
> How hard can making a t-nut be?
> 
> ...


What will this hard material do to a bandsaw blade?  A hacksaw blade is less expensive to replace.


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## mikey (Aug 13, 2017)

Bill Kahn said:


> ... So, next step is to drill some #7 holes every 3/4" and tap them (for 1/4-20)  (And then bandsaw and finish the ends.  Easy.). Surprise.  My drill bits do nothing.



Missed this the first time around. If your HSS drill bits won't drill a hole in that material then I hope you have a good supply of taps because they will very likely snap on you. I'm not familiar with a tap that requires a #7 drill in hard steel; a #7 is usually used for a 1/4-20 tap in soft stuff like aluminum, brass or plastics. In any case, I suggest you go one or two steps bigger on the drill before trying to tap that stuff.


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## darkzero (Aug 13, 2017)

JimDawson said:


> The Harbor Freight cobalt drill set seems to be pretty decent.



Believe it or not, I have to agree. I have the 118 pc & the 29pc cobalt sets from HF that I purchased yrs ago. I use them in 303, 304, & 6Al4V all the time. I told myself I would buy a nice USA made set someday to replace them but surprisingly they have been serving me well. A couple of them may have had poor grinds on them but nothing a resharpening couldn't fix. Of course their indexes suck, I put them in Huot indexes.

OTOH the HF black oxide & TiN drills aren't worth buying IMO. Although I do still have the TiN set, I gave the other set away. I use the TiN set for drilling wood or other general purpose stuff.

I have an older Craftsman USA black oxide set & they are pretty nice drills. No idea who actually made them though.


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## Charles Spencer (Aug 13, 2017)

When I retired and started my hobby shop I had an old set of Black & Decker drill bits to 1/2" and a somewhat newer set from DeWalt to 3/8".  In my younger days I had learned how to sharpen drill bits freehand so I had these for many years.  I eventually got a set of number drills, letter drills, fractional drills to 1/2", and Silver & Demming drills 1/2"-1".  I bought the fractional drills off ebay and found they were USA made drills from ca. 1950s and barely used - on wood.  I got the number drills as an incomplete set at a yard sale and ordered what I needed to complete them.  The Silver & Demming and letter drills came from Drill Hog on ebay.  They are made in the USA and have a lifetime warranty.  I've been happy with all of them.  And it's really great to have the exact size you need in a decent quality drill.  The bits from Drill Hog seem to be well made and reasonably priced.  I got the ones labelled Hi-Moly M7:

http://www.ebay.com/itm/Drill-Hog-2...Y-M7-Lifetime-Warranty-USA-MADE-/181752864050

I do like having separate sets rather than one bulky set.

Also - no affiliation with Drill Hog besides being a customer.


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## Doubleeboy (Aug 13, 2017)

JimDawson said:


> The Harbor Freight cobalt drill set seems to be pretty decent.  I have no idea what the RR spikes are made of.  I have a few out in the shop so I'm going to have to try machining one.  I'm guessing cutting at around 50 FPM would work with HSS.



I took a chance on the 118 piece set from HF, I believe they are the cobalt ones that Jim referenced.  They are jobber length 135 split point.  They go through the hard scale on A36 like butter and easily drill Air Hardened steel.  They are a screaming good deal when on sale and you add on the 20% coupon.


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## 4GSR (Aug 13, 2017)

On those railroad spikes.  If you have a way to heat them up to around 900-1000 degrees hold for about 15-20 minutes at temperature and furnace cool to under 600 degrees and let cool to ambient.  That may pull out any high hardness that is making it hard to cut with a standard drill bit.


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## Jonathans (Aug 13, 2017)

For years, I never wanted to spend big bucks on a drill bit set.  I mostly used those huge index sets from China. I had a few larger USA silver Demi g bits. Got the job done.
Then I purchased a "good" set of Dewalt bits that had a built in pilot bit at the tip. Good bits that got the job done better.
For hard work I picked up a set of Dewalt cobalt bits. Brittle, but even better.

A month ago I purchased a set of KnKut stubby bits (these are the bits that supposedly can drill through a #8 bolt easily).
  I had to mount a swing arm to my Bridgeport and to do so had to drill some 5/16 holes and tap them into the cast (which was MUCH thicker than I had expected).
I first drilled the holes with a Dewalt cobalt 1/8 pilot.  Took a long time. Then I drilled out one hole to 5/16 with a Cobalt bit. Took around 10 to 15 minutes, and was difficult.  
I then decided to try one of my new expensive KnKut bits.  Holy crap! it drilled right through an a minute or so, maybe less!  I was amazed at the difference.  All bits were new. All were 135 degree.
I guess you get what you pay for sometimes.  I'm 61 and spent many years drilling with crappy bits.


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## Bill Kahn (Aug 13, 2017)

DaveInMi said:


> What will this hard material do to a bandsaw blade?  A hacksaw blade is less expensive to replace.


My small HF bandsaw is doing well.  I have destroyed many blades in trying to learn to cut lead bricks.  (But have something that is working now for that too.). But for most of my work I have been using https://www.amazon.com/gp/product/B010BOLYP4/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1 at high speed.  It has cut through hard stuff, like these railroad spikes, that HSS bits have been destroyed by.  Not fast but nice thing about a bandsaw is it is largely launch and forget until the noise stops.


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## Bill Kahn (Aug 13, 2017)

Charles Spencer said:


> ... I got the ones labelled Hi-Moly M7:
> ...





I have see bits labels as M42 (seems like these are good for drilling hard steel).  I also see M35 advertised.  Are these I gather are also good, but not quite as good as M42.  But is M35 good in some other way, like less brittle or something?  And I see the M7 label too.  Apparently also very good.  Is there a list somewhere of the standard material drill bits are made out of what each material is good, and not so good, for?


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## DaveInMi (Aug 13, 2017)

Bill Kahn said:


> My small HF bandsaw is doing well.  I have destroyed many blades in trying to learn to cut lead bricks.  (But have something that is working now for that too.). But for most of my work I have been using https://www.amazon.com/gp/product/B010BOLYP4/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1 at high speed.  It has cut through hard stuff, like these railroad spikes, that HSS bits have been destroyed by.  Not fast but nice thing about a bandsaw is it is largely launch and forget until the noise stops.


That is great news.  I just ordered from them.  Thanks


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## 4GSR (Aug 13, 2017)

Bill Kahn said:


> I have see bits labels as M42 (seems like these are good for drilling hard steel).  I also see M35 advertised.  Are these I gather are also good, but not quite as good as M42.  But is M35 good in some other way, like less brittle or something?  And I see the M7 label too.  Apparently also very good.  Is there a list somewhere of the standard material drill bits are made out of what each material is good, and not so good, for?



M7, M35, M42, they are all Cobalt based tool steel.  And for the H-M, they will drill just about anything you want them to do.  As for one shattering,  M42 are pretty tough.  I have a few that are M7 material and with the sound they make when bumped I think they would shatter just from dropping.  Haven't tried.  I've bought several used sets of HSS and Cobalt drill sets off of ebay over the last few years.  It's hit and miss on what you are bidding on.  You can study the pictures and after a while determine what is good and what is junk.

BTW:  They only have one of these left in stock!  Don't sneeze! Someone may buy it! "And for $945 https://www.amazon.com/Cleveland-C7...83604&sr=1-1&keywords=115+piece+drill+bit+set "


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## Ken from ontario (Aug 13, 2017)

4gsr said:


> M7, M35, M42, they are all Cobalt based tool steel.  And for the H-M, they will drill just about anything you want them to do.  As for one shattering,  M42 are pretty tough.  I have a few that are M7 material and with the sound they make when bumped I think they would shatter just from dropping.  Haven't tried.  I've bought several used sets of HSS and Cobalt drill sets off of ebay over the last few years.  It's hit and miss on what you are bidding on.  You can study the pictures and after a while determine what is good and what is junk.
> 
> BTW:  They only have one of these left in stock!  Don't sneeze! Someone may buy it! "And for $945 https://www.amazon.com/Cleveland-C7...83604&sr=1-1&keywords=115+piece+drill+bit+set "



I would always check the price on amazon Canada, guess what, the one you linked is only $687.93 on amazon.ca, and that is in Canadian dollar so in fact it is around $600 USD:
https://www.amazon.ca/Cleveland-C70...int,+1/16"+to+1/2",+A+to+Z+and+#1+to+#60+Size


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## 4GSR (Aug 13, 2017)

The M35 grade is more than likely the Chinese destination for their "Cobalt tool steel"  they are used to using.  Their steel numbers generally follow the DIN/Germany destinations.   Why doesn't the rest of the World not follow the AISI system?  Oh well! Can't change it now.


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## Eddyde (Aug 13, 2017)

I think a good strategy is to get good quality HSS sets for general work and buy individual cobalt drills only as needed. I have some letter and wire size drills I have never used in 30 years, yes its reassuring to know I have em "just incase" but no need to buy all those sizes in cobalt.


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## Terrywerm (Aug 13, 2017)

About ten years back I thought I was being smart by purchasing one of those 115 piece drill bit sets from Enco. They weren't bad, but not great, fine for general purpose work. Life was good until the one day when I knocked the entire drill index off of the bench and onto the floor. Spent the next couple of hours measuring most of the drill bits with a micrometer to get each one back into its correct spot.

Now here I am years later, some of the bits are broken, some are lost, but a fair number need replacing. Instead of purchasing another set of the cheap ones, I have decided to purchase separate letter and number bit sets in separate Huot indexes, and purchase higher quality bits while I am at it. I don't think I will regret my decision. At least if I spill an index I know where all of the bits belong much more easily.

As for cobalt bits and end mills, I do have a few of them, purchased individually for specific projects. They all reside in their cardboard or plastic sleeves and are used only as necessary. My cheap bits are the ones that I leave where my adult children can find and use them. The good stuff is hidden away... if anybody is going to break or lose the expensive stuff, it's going to be ME! That way I don't grumble about the replacement expense.


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## Bill Kahn (Jan 13, 2018)

Bill Kahn said:


> Beginner's question...
> I have a cheap 115 piece HSS drill bit set.  Works fine on softer materials.  But there are steels it does not work on.  (I do not know how to evaluate steel--but I am working on old railroad spikes now.  Carbide end mill works on it.  My cheaper HSS end mills do not.)
> My drills bits do not drill the railroad spikes.
> So, how do I figure out what drill bit set to buy that can work on such harder steel?
> ...


Just checking back in here and letting folks know what I did..

I purchased Shars 415-7655, 415-7656, and 415-7657

http://www.shars.com/ms26c-a-z-26-pc-cobalt-straw-finish-jobber-drill-set
http://www.shars.com/ms29c-1-16-1-2-x-64ths-29pc-cobalt-straw-finish-jobber-drill-set
http://www.shars.com/ms60c-1-60-60-pc-cobalt-straw-finish-jobber-drill-set

USA cobalt M-42 135 degree split point jobber

I could not find the stub length I really wanted at anything approaching the price I could swing.  As it was, these were a bit on the high end for me--like $350 altogether.

BUT--wow, they are way way better than my cheap set.  Way better.  I mean, for wood probably makes no difference.  But I have some steel (railroad spikes, for free along abandoned tracks) that only my carbide endmill can handle.  And these bits drill right through it.  No problem at all.  My cheap bits can't do a thing to that steel.

So, I can drill steel now.  A big step up.  Pretty silly to have a lathe and a mill, with carbide tooling, and not be able to drill holes.  Now I can.  Yippee.

-Bill


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## Mitch Alsup (Jan 13, 2018)

I have and am enjoying that 115 cobalt HF set.

They drill through everything I want drilled, and I have only broken 1 of them in the 6 months I have owned them (#43 4-40 thread tap hole size). Have not had to sharpen any of them either.


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## Doubleeboy (Jan 13, 2018)

I also have the large HF cobalt set, 135 degree, on sale and then used a 25% off coupon, so got set for well under a hundred.  They compare favorably to a no name USA made set I got from Enco a dozen or so years ago.  Unlike other HF bits they do not appear to be ground by drunken monkeys.   It looks like HF is selectively raising their game, importing some pretty nice tools. I hope they start selling quality screw drivers soon, so far it looks like the drunken monkeys still have the contract to produce their screwdrivers.


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## Bill Kahn (Jan 14, 2018)

Bill Kahn said:


> Just checking back in here and letting folks know what I did..
> 
> I purchased Shars 415-7655, 415-7656, and 415-7657
> 
> ...


Oh, just a heads up.  As fancy as Cobalt M42 bits might be, they still can't drill a ball bearing.  I guess someone who understands hardness and stuff would theoretically know, like duh, of course not.  Me, without the understanding, figured it out by trying.  -Bill


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## EmilioG (Jan 14, 2018)

99% of my twist drills are USA or Made in Germany. I buy them individually, as I need or find them at a good price.
A few years ago, I bought a big lot of Guhring solid carbide & cobalt drills for $30. They are all new. Retail, the lot must have
come to about $800 or more. 

I got frustrated with cheap drills breaking or not holding a sharp edge for long, so all of my drills
are good quality; C-L, Cleveland, OSG, etc....with a few PTD, Morse, Melin, and a few others. Big difference.  All in Hout indexes and
divided into categories/use.  Look for a good sale on a fractional set. I would start with HSS bright., then buy Cobalt as you need them.

Like RJ wrote, Cheap drills are a crap shoot.

The men here have been collecting drills for years. Soon you'll have more drills that you'll ever need.
(are there any woman HM's here?)


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## projectnut (Jan 14, 2018)

mikey said:


> Funny but the longer I'm in this hobby, the more I find myself buying things that I can easily make but that are cheaper to just buy. For me, T-nuts would fall into that category but when I started out, I tried to make everything myself just to learn how to do it so I get it. I would suggest you try it on mild steel, though!



I also find many times it's cheaper (and far less time consuming) to purchase some parts.  However in my case I still make a batch of T-nuts on occasions.  I do use a variety of sizes, and always seem to be a couple short for larger projects.  In addition I hate to pay shipping.  It seems that more often than not the small number of items I want to purchase are less expensive than the shipping costs.  This always seems to be the case with T-nuts, so about once a year I run off a batch of whatever sizes I'm short on.  I usually make a dozen or two at a time.  Then I can loose them, modify them for single time use, or for special purposes, and still have enough to clamp things in either of the mills, the shaper, the rotary table, or any other machine in the shop that needs them.  They're easy to make and cost effective if you do multiples at one time.


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## Bob Korves (Jan 14, 2018)

I don't buy t-nuts because they are not made to sizes that actually fit my t-slots.  I also do not like that they are hardened, which is more damaging to the t-slots.  Durability of hardened vs. mild steel t-nuts is not an issue in a home shop, at least not in mine.  So I make them, and enjoy the nice fit and craftsmanship every time I use them.  They are just a commodity as commercially made, and not very expensive, but I prefer making them myself to my own standards.


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## ericc (Jan 15, 2018)

Hi.  I was just working with railroad spikes yesterday.  They can be cut, welded, and drilled just fine with just about anything.  They can be threaded with cheap carbon steel dies, and drilled with any sharp bit.  The catch is that the HC spikes should be annealed, especially if they have a wear mark below the head.  That means that they are end of life and are probably work hardened.  The carbon content is about 25 points, so they will harden.  Almost all my railroad spikes projects that are machined are done in an "as forged" state, which basically is normalized.  This is good enough, but I do know some blacksmiths who insist on annealing in vermiculite. It just makes things easier.  Annealing is more critical if you want to reuse rail clips or automobile springs.  In that case, as forged is often too hard to drill, but a furnace anneal or sub-critical anneal will work.

By the way, I hear a lot of comments about $20 cutting tools.  $20 will buy a lot of new drops at the scrap metal store at $0.60 per pound.  Even paying $2 per pound for new will get me a lot of good stock.  Even if you are just selling a few crafts, the new steel is worth it.  If you have regular commitments, or even worse, a commission with a deadline, you will have no trouble meeting the minimums at the steel yard.  Your shop is just moving too much product.  Found steel and little unknown pieces of junk are fun for shop tools, but it hurts to goof up a $20 tool on a $2 piece of steel.


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## 682bear (Jan 15, 2018)

Speaking of chinese drill bits... several years ago I was attempting to enlarge a hole ... I grabbed a chinese bit (just because it was laying there nearby) and put it in my cordless drill. It was actually drilling, somewhat... but as it broke through it grabbed... and straightened the twist out!


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## tq60 (Jan 19, 2018)

We get many loose bits at estate and other sources.

At a local annual sale we got a bundle of very old bits from likely factory from way back when in paper pouches brand new very old stock maybe 50 to 100 bits for 5 bucks.

For a project we needed stubby or screw machine length so checked amazon and found a set of Cleveland in warehouse deals for 34 bucks.

Had great reviews and one with single star that made us crack ....complained about them being set short...You buy short drills then complain that they are short?


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