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Widder, SASS #59054

HELP with Drill Bit info

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I would like to have a good drill bit for 'STEEL'.

 

Most of them advertise for 'metal', but fall short being good for actual 'steel'.

 

I've had some success with a couple from Dewalt with their carbide coated tips.

 

BUT, it there another brand that might be better.

 

The steel I am drilling is only about 1/8" thick and I only need about an 1/8" hole.

 

Thanks

 

..........Widder

 

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The carbide bits are just fine. One problem is that you may be using too high of a speed. That creates a bunch of heat real quick and destroys the bit quickly. Use a lower RPM on the drill. You'll see what I mean.

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After MANY years and many drill bits I now only use Cobalt drills for steel. You can run them faster than typical HSS bits. Ti coated ones don't last long. Carbide bits are run slow for special applications.

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What do you use for cutting oil? I use Tapmatic gold.

Use a Drill Doctor to sharpen my drills.

I use drills made buy Viking Drill & Tool.

I have drill sets in fractions up to 1/2 inch, along with 'letters' and 'numbers'

OLG 

 

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23 minutes ago, The Original Lumpy Gritz said:

What do you use for cutting oil? I use Tapmatic gold.

Use a Drill Doctor to sharpen my drills.

I use drills made buy Viking Drill & Tool.

I have drill sets in fractions up to 1/2 inch, along with 'letters' and 'numbers'

OLG 

 

 

I use a butter knife when I cut oil.   :lol:   (sorry, I couldn't resist).

 

Looks like a got a little shopping to do.   Thanks for the info, Pards.

 

I did try some slow drilling, but it may not have been slooooooow enough and I may

have dulled the tip.

 

..........Widder

 

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Cobalt steel is the only way to go and as OLG said, don't drill dry.

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I use IWM cobalt bits with regularity. Cobalt in general is all I use to drill mild steel

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In hard steel, keep your rpm @ 200-300.

Your feed will depend on the drill diameter. 

Never drill metal 'dry'.

Aluminum you can up your rpm a good deal. 

OLG 

 

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I was buying Irwin brand cobalt bits from local Ace Hardware as I had a need to drill something hard.  I finally got fed up using junk bits and decided to just buy a set of Irwin cobalt bits.  I went to Ace Hardware and there where they had them for years was a hole 4' wide. I asked the helpful hardware man for assistance.   He said they were reworking the displays and to come back next week.  Some help that was.   But I returned a week or more later and looked high and low for Irwin cobalt bits.  None anywhere.  So back to helpful hardware man.  Oh,  they stopped carrying Iwrin, now DeWalt.  The DeWalt were considerably higher but I picked up a set and headed to checkout.  The closer I got, the less I wanted to be forced to buy something I didn't want at a higher price.  So.... I put them back and started looking on eBay.  But before I placed an order,  we happened to be in a well stocked independent family-owned hardware store.   There they were,  the Irwin brand and assortment I was looking for and at a better price.

 

Irwin brand cobalt bits work for me. 

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Very much druther go to a smaller local place and pay a bit more (but sometimes a lot less, too) for many things: guns and gun stuff, tools, electrical stuff, auto parts, most hobby supplies, and mens shirts.  If i can't get it locally I turn to the internet and people like Home Depot, Lowes, Kohls and many others never miss my few coins, but I'm appreciated at the local places.....and they usually, not always but usually, have someone there who actually knows what they are talking about.

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10 minutes ago, Subdeacon Joe said:

 

Bet that chart is primarily for a lathe.

It is hard to guess RPM with a hand held drill motor. ;)

OLG 

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 BEFORE YOU DO ANY DRILLING IN METAL

 

Use a center punch (pointed) at the mark where you want the hole, and strike it a good blow.  The resulting “divot” gives the drill bit something to grab, gets it started quickly, and the bit won’t heat up as much.  Doing this extends the life of the drill bit.

 

Cat Brules

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33 minutes ago, The Original Lumpy Gritz said:

 

Bet that chart is primarily for a lathe.

It is hard to guess RPM with a hand held drill motor. ;)

OLG 

 

Lathe or mill.  I posted it mainly to give some sort of reference- fast and fast, slow and fast, slow and slow. 

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26 minutes ago, Cat Brules said:

 BEFORE YOU DO ANY DRILLING IN METAL

 

Use a center punch (pointed) at the mark where you want the hole, and strike it a good blow.  The resulting “divot” gives the drill bit something to grab, gets it started quickly, and the bit won’t heat up as much.  Doing this extends the life of the drill bit.

 

Cat Brules

 

Use the punch and then a center drill, if you are freehanding the hole.

No need to 'punch' with a mill or lathe.

OLG 

 

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I have a full set of Lawson carbide drill bits. The set goes from 1/16” to 1/2” in 1/32” increments. I have had this set for years. I do not use the bits often but when I need them they work great. I have used all the smaller bits 1/4” and smaller numerous times but they seem as sharp as they did when new. 
 

I don’t recall what I paid for them. This is the set I have. 
https://www.lawsonproducts.com/lawson/Drill-Bit-Set-Carbide-15-Pcs/1239014.lp

 

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A lot of the performance of a drill bit depend on the drill point geometry and how it was sharpened. Carbide is great for harder steels, but you have to be s careful as they will shatter if they are not used with the correct rpm and drill point geometry for the material you are drilling in. I am an experienced Manufacturing/Tool Engineer who has engineered the tooling that was used on the B1 bomber, Space Shuttle and B2 Bomber in production to drill close tolerance fastener holes in Titanium and steel. We drilled holes on the assembly line up to 1" in diameter thru 5 to 6 inches of titanium and high strength steel to a tolerance of +/_ .0005 of an inch. For the normal home use drilling, cobalt steel cutters with the correct point geometry will do the job just fine.

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And drill a pilot hole if you are going to larger sizes

 

Imis

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You'll be awed by the difference  a little tap oil will make. Especially with larger bits, like going from steel to wood! You can get it at any hardware store and will last forever almost. I like the spay version, but not as easy to find. Any sort of oil is way better than dry.

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18 hours ago, Widder, SASS #59054 said:

 

I use a butter knife when I cut oil.   :lol:   (sorry, I couldn't resist).

 

Looks like a got a little shopping to do.   Thanks for the info, Pards.

 

I did try some slow drilling, but it may not have been slooooooow enough and I may

have dulled the tip.

 

..........Widder

 

Coolant is critical with all steel boring and machining.  Tap magic is a good product, but it contains a small amount of petroleum lubricants intended for thread tapping.  Standard boring coolants are usually made from animal fat formulations or from glycols with vegetable component materials.  (try some antifreeze sometime!) They are for cooling, not for lubricating.  Lubrication is usually counterproductive to metal material removal operations.  

 

And remember, you want to cool the boring bit--not the workpiece.  That's hard to do with vertical boring, due to gravity.  Most vertical applications simply require flooding coolant onto everything.   

 

No (steel) material removal tool will last very long, even on mild steel, and you certainly won't get precise round borings if no coolant is used with any standard twist type drill bit.  If hole roundness is critical, be sure to use a drill guide to prevent run-out.  

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