Best drill bits for harder metals

[Drill Bit]

I am looking to spend on a good set of drill bits which will cope with most harder metals.

What would anyone recommend brand wise.

Research shows TTP HARD drills as a good option - has anyone tried them ?

[ThomasPowers]

EDM

[Drill Bit]

Great thanks

[Kozzy]

Forbidden bug 

[j.w.s.]

I like Artu but you can't use them on mild or annealed steel and you need a press with fast rpm, cutting fluid helps.

J

[BIGGUNDOCTOR]

I use solid carbide ones at work for drilling broken taps. What do you consider hard?

I would say just get a set of USA made HSS drills. Either bright, or black oxide finish. That is what I use the most at work as the tool maker for a machine shop.

[SpankySmith]

I've tried a BUNCH and keep coming back to Irwin, used to be able to buy them at the local Ace Hardware but that store closed, have to order them online now. 

[Alan Evans]

I am looking to spend on a good set of drill bits which will cope with most harder metals.

What would anyone recommend brand wise.

Research shows TTP HARD drills as a good option - has anyone tried them ?

Do you mean hard metals like steel and cast iron as opposed to soft metals like copper and aluminium?

In the UK Presto or Dormer make good quality high speed steel drills in sets which will cope with most mild and stainless steels and all of the soft non ferrous metals. Don't buy the cheap TiN coated sets, however many bits they contain.

Forty years ago I bought  a set of imperial and later a set of metric. Still going strong like Grandad's axe...five new handles and two new heads . ...... I then buy replacements in boxes of tens to restock the "working set".

If you are looking to drill harder materials I would buy as required for the specific material and project....a full set of cobalt or solid carbide would be fairly costly.

The most important thing to do though is learn how to sharpen them. Seconds to do...minutes to learn... and hours saved... using sharp drills. You can even modify the angles to suit the material.

Alan 

[fergy]

EDM

would be my choice to 

all sizes and shapes 

Do you mean hard metals like steel and cast iron as opposed to soft metals like copper and aluminium?

In the UK Presto or Dormer make good quality high speed steel drills in sets which will cope with most mild and stainless steels and all of the soft non ferrous metals. Don't buy the cheap TiN coated sets, however many bits they contain.

Forty years ago I bought  a set of imperial and later a set of metric. Still going strong like Grandad's axe...five new handles and two new heads . ...... I then buy replacements in boxes of tens to restock the "working set".

If you are looking to drill harder materials I would buy as required for the specific material and project....a full set of cobalt or solid carbide would be fairly costly.

The most important thing to do though is learn how to sharpen them. Seconds to do...minutes to learn... and hours saved... using sharp drills. You can even modify the angles to suit the material.

Alan 

solid advise right here ^^^^^^^^^

[Kozzy]

Forbidden bug will probably bite again but the original question teeters on an actual machining term that hasn't been clarified--"hard milling/drilling".  In machining terms, that is not about harder metals in general but specifically about milling things that have already been heat treated or are super hard to begin with.  If that's what the O.P. means, it requires very specific and complicated answers---cobalt bits would be at the bottom end of hard drilling and not usually used.  You start to get into things like polycrystalline diamond tips and such when machining truly hardened stuff.

I have to assume the O.P. simply means drilling the harder end of the generally soft metals...annealed high carbon and such.  Cobalt is probably the material of choice for the average user as it's still affordable and doesn't snap like carbide if you twitch.

I'd personally buy a full set of high speed steel bits in a drill index for 90% of drilling needs.  Not the home center junk but a set from a true machinist supplier.  Then I'd fill in as needed with specific cobalt bits---again, the good stuff and not home center.  If one can do a rigid set up and the holes are small (like rivet sized), solid carbide is often worth it. 

Good quality bits are an order of magnitude better than the home center stuff.  Similar is true with taps and dies as well as sandpaper/abrasives.  Home centers cater to price and people who will never know the difference.  

Fancy coatings are not usually beneficial except in high production situations.  Home center coatings are mostly just pretty colors to sell bits.  China mart drill bit coatings are about as useful as paint.

Keep your metalworking bits separate from wood use.  Get a separate set of brad-point bits for your woodworking...plus a few forstner bits for the large holes.  Also have a pile of worse bits around in case someone decides to borrow from you..never loan your good bits.

 

[ThomasPowers]

My solid carbide twist drills live in their own compartmentalized plastic box  one per compartment and students, friends, my wife, etc are NOT allowed to even move the box.---I try to buy them as I find them cheap at the fleamarket; don't have too many but sometimes you have to drill a hardened knife blade...

[ianinsa]

Some good advice here! And IMHO with the exception of pawnbrokers and fleamarkets, places that sell cheap tools(often at high prices) rarely stock good quality drill bits.

Typically industrial suppliers keep better quality stock, you may not need cobalt but phone and ask if they have them, if so you'll find their HSS bits are better than those in the Home Depot type stores

And as Alan pointed out 'bulk package' ie. 10 bits same size are typically industrial as opposed to DIY  

[zombieresponder]

I am a machinist by trade, just so you have some background.

Drill bit "sets" are a waste of money. All of them I have ever looked at are overpriced for what you get. The comments from others about buying them from an industrial or machinist supply house are right on, and you'll probably spend less or about the same as going to the hardware store and buying a single drill.

If you're drilling hardened steel(above say 45 HRC), then your only real options are carbide or EDM. If you're drilling something like PHT4140, which is around 30HRC, then I would suggest a cobalt alloy drill with a 135 degree(most drills are 118 degree) split point. For anything else, standard 118 degree HSS drills will work just fine. Just don't buy them at big box stores or the ones made in china. I don't ever recall using any Presto brand drills, but Dormer makes good stuff as do many others. The chinese drills generally have poor heat treating and are either way too hard and chip/break or are too soft to hold an edge.

[Alan Evans]

…SNIP...Drill bit "sets" are a waste of money. …SNIP...I don't ever recall using any Presto brand drills, but Dormer makes good stuff as do many others. The chinese drills generally have poor heat treating and are either way too hard and chip/break or are too soft to hold an edge.

I bought good "sets" of industrial standard HSS jobber drills from Dormer and Presto…which gave me one of everything in a handy metal container. Then I reckoned to just use 1/8" 3/16" 1/4" for general pilot hole drilling so I did not have to buy replacement boxes of ten of everything to start with. Just lack of finance dictating good house-keeping when starting out. The metal containers are still going strong after forty years.

http://www.presto-tools.co.uk/en/categories/twist-drills

Presto do a resonable selection including armour piercing...

My brother in law bought one of the imported multi drill bit cheap sets from a travelling tool dealer and complained that they would not cut very well. When I had a look I discovered that they had been sharpened by hand before the TiN coating and many of them had the cutting angle in reverse! A right hand twist bit with a left hand edge...I could not believe it! The cheap 50 piece set cost £10 which is less than one decent 1/2" Presto / Dormer bit though!

Alan

[zombieresponder]

I have never seen a Dormer set of drills, or any other industrial/machinist brand. All of the sets I've seen, including in machinist tool catalogs, have been off brands, and overpriced. Drilling pilot holes isn't a bad idea, though it's typically best to use a drill that's the same size as the web of the drill. That said, if your larger drills are split point and properly sharpened they will go right through with much less effort than you might expect.

 

I've seen right hand twist drills from reputable brands that were factory sharpened with left hand cutting points. I've also seen the flutes straighten out due to improper heat treatment.

[BIGGUNDOCTOR]

Good suppliers like MSC will offer sets by makers such as Cleveland Twist Drill. They are not inexpensive, but they are offered. I bought my sets at machine shop auctions and have been refilling them as the bits wear out, or break. I am getting spoiled at work, as we mostly use solid carbide for everything now. They last longer in the screwmachines , and we do some long runs in the 100,000's of parts. They are brittle though, so they have to be used in a machine tool, but they do make broken taps an easy removal now.

[Frosty]

35 years ago I bought an index of Bowman cobalts and have never regretted it. They're my go to bits for tough stock. The one downside is they're self centering so you need a special grind stone to sharpen them. However, if you're careful to never drill dirty or ground stock they don't seem to dull.

Nothing takes sharp off a drill bit like drilling into steel that's been ground as grit worn off the wheel/disk/belt is embedded in the steel and grinds the edge off the bit. On rare occasion I've needed to drill into a ground surface and sacrifice a file first. Dulls the file but saves my Bowmans.

So, that's my $0.02. Good bits and take care of them. NO dirt! I learned to sharpen HSS bits from Dad, metal shop classes were good practice, some of the other guys never got the hang of it. Dad taught me how to sharpen almost anything.

Frosty The Lucky.

[zombieresponder]

I've got a pile of inserted carbide drills, some of them brand new, that I picked up at a scrap yard a few weeks ago. There were a couple tons of morse taper shank drills, spade drills, and HSS spade inserts there as well. Found some inserted threadmills at a garage sale a couple weeks ago too. Sold the threadmills to my boss. Need to clean the other stuff up + some cat 50 holders and put it on craigslist. Anyone need any cat 45 pull studs? LOL.

[BIGGUNDOCTOR]

Sounds like you could start an eBay store with all of that pile. No fan eBay, but it does move stuff.

[Munra]

The best drill bits I used at work are PartMaster Cyrobits 

CyroBits

They cut mild steel with ease and I have had no problem when ever I needed them to cut tool steel.   

 

 

[tompdw]

American made 135deg split point cobalt is what I use.