Let's talk drill bits - need advice

[Baja 252]

I need to drill a couple dozen 1/2" holes in 3/16" angle iron and channel on our dock. Because of the awkward location and and being close to the water I have to use a cordless drill.
I've got a bucket of old drill bits that don't cut anymore and I'm tired of cheap bits that go dull in drilling just a couple holes.
Which ones are the best with out going to some high $$ machine shop quality? I see titanium ones? Cobalt ones ?
What type of bit? Am I better off drilling a small hole and working up to 1/2" with 3 or 4 different bits or should I get the pilot point drill bits that have a small tip that drills a small hole then jumps right to 1/2" in the same bit?

 

[Your ad here]

I've found drill speed is the killer of bits aside from the obvious. For 1/2" I would step drill it. 1/8", 1/4", 3/8", 1/2". If you can get away with a 9/16" hole look into carbide tipped hole cutters.

https://www.amazon.com/Champion-Cutting-Tool-CT7-1-Tungsten/dp/B0016J8G64/ref=sr_1_3?crid=6QLXYNBP0U7R&dchild=1&keywords=champion%2Bcarbide%2Btip%2Bhole%2Bsaw%2Bkit&qid=1615740671&sprefix=Champion%2Bcarbide%2Caps%2C218&sr=8-3&th=1

 

[buck35]

I like the step approach. also be sure to use a cutting fluid or some anchorlube,saves the bits and drilling is faster and far easier.

 

[dspracing]

2 dozen holes, I would get 2-3 pilot point bits, run em dry and go for it. Toss em when they are spent. Spend a little more but you will blaze through the job. The step approach is a killer on the wrists as you get into the larger sizes and the bit catches.

 

[LazyLavey]

you can get these cheap on sale..... they're disposable

Step Drill Bits

Enjoy more drilling and less downtime with Harbor Freight step drill bits. Automatically deburr holes as you drill through metal, plastic, and wood.

www.harborfreight.com

 

[Nordie]

Leverage and speed is your friend. I'm not a Milwaukee guy, but I have a set of their cobalt bits and they are sharp and hold up well. Don't forget the cutting fluid.

Or find a buddy that has a mag drill that is brave enough to loan it to you.

 

[rrrr]

Buy a Drill Doctor sharpening tool. It actually works. When you get the hang of sharpening bits with it, they can be resharpened over and over. Be aware of heat buildup while using the tool, take it slow so it doesn't affect the heat treatment of the bits.

 

[Ziggy]

Too much speed = too much heat = burned up bits.
The step bits can work well if treated right and ease the wrist twist pain.
Recently had to drill 1/2" holes through 1/8" mild steel and the step bits ripped right through that stuff but got eaten up by the 1/4" stainless I was mating that to.
Broke down and bought some decent cobalt bits at HDepot which did the job nicely on the stainless. Slower speed and plenty of oil.

 

[TimeBandit]

I would drill 1/8" pilot holes then use a 1/2 in UniBit Step drill to go the rest of the way.

Step drills cut round holes where common drill bits tend to drill triangles when used by hand.

Amazon.com: IRWIN Step Drill Bit, 1/8-Inch to 1/2-Inch Step, 1/4-Inch Shank (10231): Home Improvement

 

[Nordie]

These are my get it done bits, I have lesser ones I really don't care about as much.

 

[Ziggy]

These are my get it done bits, I have lesser ones I really don't care about as much. View attachment 981849

Lol, those are the ones I purchased. Worked just fine.

 

[Nordie]

Lol, those are the ones I purchased. Worked just fine.

They're fucking sharp, I'll give em that...I don't think I've done any stainless, but once you put heat into stainless you're not going to go through it as it work hardens. I had some Dewalt titanium ones that worked very well, but someone decided that they liked them more than I did and walked away with them.

 

[Racey]

Stepping can be a double edged sword in some cases, if you have a real sharp drill, and a soft material (like mild steel) the fact that the drill can focus so much power into such a small area can cause it to over bite and suck itself in.

If you have good drill bits and a strong drill motor i would just go 1/4" to 1/2" in a single step on mild steel angle.

Do not over speed the drill, for 1/2" bit you should probably be running about 300rpm free drilling, use that throttle control and correct pressure. you will have an arm workout when done.

 

[Gramps]

any good?????

Blue Bullet Drill Bits. Strongest Drill Bits In The World.

For over twenty years, Rodman’s multipurpose bits have been the go-to drill bit for professionals, such as locksmiths and auto mechanics, who often come up demanding drilling applications. Now, homeowners can utilize Rodman’s multipurpose drills for drilling in all ferrous metals, porcelain...

bluebulletdrlll.com

 

[Icky]

You have to get stainless pretty hot to work harden it then you need a fancy drill bit. We primarily drill stainless, more pressure less speed and 95% of the time we're running cordless Milwaukee drills.

I would go from a shorty 3/16" pilot straight to a 1/2" bit, and use some rapid tap. That way you can put pressure on it without the pilot breaking. I've never really noticed a difference other than split tip, but we usually throw away drill bits when they're dull unless they're a larger size.

 

[Baja 252]

Thanks for all the quick responses. I think I'm running the drill too fast, I'll slow it down.

 

[rivermobster]

Stepping can be a double edged sword in some cases, if you have a real sharp drill, and a soft material (like mild steel) the fact that the drill can focus so much power into such a small area can cause it to over bite and suck itself in.

If you have good drill bits and a strong drill motor i would just go 1/4" to 1/2" in a single step on mild steel angle.

Do not over speed the drill, for 1/2" bit you should probably be running about 300rpm free drilling, use that throttle control and correct pressure. you will have an arm workout when done.

You should post a link to your sharpening thread...

 

[Icky]

At the end of the 1/2" hold you will probably have to speed it up with less pressure as it will start to grab. Unfortunately this is also how you break the tip of your bit

 

[waterhorse]

I had a buddy ask me a similar question years ago about drilling several holes in some plate steel, I told him to start with a small bit and work your way up to the size you need. I stopped by after a couple hours to see how he was progressing, he only had 2 holes completed so I asked what was the hold up? He said I did as you suggested and started small and worked my way up. I said, Geebus H. Chrysler not with every single Flippin bit size in the drill index, he was a bit anal on stuff and could and still does make any and every task more complicated than a space launch.

 

[LowRiver2]

These are my get it done bits, I have lesser ones I really don't care about as much. View attachment 981849

These are what we are issued

Question for all:

Conex containers :

Who has drilled into these on sides and roofs with hole saw bits?
What were the best brands, drills, etc.?

We have to get into them once in awhile at the port for WMD and other stuff to get probes and snake cameras in.
Always looking for better tools for that job.

 

[Racey]

any good?????

Blue Bullet Drill Bits. Strongest Drill Bits In The World.

For over twenty years, Rodman’s multipurpose bits have been the go-to drill bit for professionals, such as locksmiths and auto mechanics, who often come up demanding drilling applications. Now, homeowners can utilize Rodman’s multipurpose drills for drilling in all ferrous metals, porcelain...

bluebulletdrlll.com

Those are just common carbide tipped drills, they work good in certain applications, but are very prone to chipping and once they are chipped resharpening options is very limited.

 

[lbhsbz]

Go to McMaster and buy a couple 1/8”, 5/16”, and 1/2” screw machine length drills in HSS. Use the drill in low speed, lots of feed pressure, and use Oatey dark thread cutting oil from the plumbing section at Home Depot. Just dip the tip of the drill before you start each step.

Home Depot drill bits are for making holes in wood, regardless of what the packaging says.

 

[scottchbrite]

These are what we are issued

Question for all:

Conex containers :

Who has drilled into these on sides and roofs with hole saw bits?
What were the best brands, drills, etc.?

We have to get into them once in awhile at the port for WMD and other stuff to get probes and snake cameras in.
Always looking for better tools for that job.

I’ve used Milwaukee and Lenox for some thick steel. What about a roto broach kit? I think you can set them up for a hand drill.

 

[LowRiver2]

I’ve used Milwaukee and Lenox for some thick steel. What about a roto broach kit? I think you can set them up for a hand drill.

I have the lennox bits . They work okay slow, was wondering of anything worked faster.
We have old Roto Zips but they vibrate like crazy, not enough power.

 

[scottchbrite]

I have the lennox bits . They work okay slow, was wondering of anything worked faster.
We have old Roto Zips but they vibrate like crazy, not enough power.

I just did a quick search and this is the first thing that I clicked. Something like this is what I was talking about. I believe our Haz-mat guys use something like these for drilling tanks.

Rotabroach Hole Cutters | Blair Equipment

Rotabroach Annular Cutters, cut clean, burr-free, round holes fast, in sheet metal and thin plate materials.

www.blairequipment.com

 

[RiverDave]

Stepping can be a double edged sword in some cases, if you have a real sharp drill, and a soft material (like mild steel) the fact that the drill can focus so much power into such a small area can cause it to over bite and suck itself in.

If you have good drill bits and a strong drill motor i would just go 1/4" to 1/2" in a single step on mild steel angle.

Do not over speed the drill, for 1/2" bit you should probably be running about 300rpm free drilling, use that throttle control and correct pressure. you will have an arm workout when done.

this.. good rule of thumb when drilling steel. If the drill is spinning slow you can see the flutes “climbing” up.. about the time that starts to turn into a “blur” is gonna be about the right speed for that drill size.
Don’t forget cutting fluid!

 

[LowRiver2]

I just did a quick search and this is the first thing that I clicked. Something like this is what I was talking about. I believe our Haz-mat guys use something like these for drilling tanks.

Rotabroach Hole Cutters | Blair Equipment

Rotabroach Annular Cutters, cut clean, burr-free, round holes fast, in sheet metal and thin plate materials.

www.blairequipment.com

Looks good
Will be ordering one
Thanks!

 

[Nordie]

These are what we are issued

Question for all:

Conex containers :

Who has drilled into these on sides and roofs with hole saw bits?
What were the best brands, drills, etc.?

We have to get into them once in awhile at the port for WMD and other stuff to get probes and snake cameras in.
Always looking for better tools for that job.

Cutting torch or a plasma cutter lol...wouldn't be a good idea with what you do, but want to talk about getting in there quick.

Milwaukee makes a cordless mag drill, that's what you guys should be looking at. It will make a perfect hole, that's what they use to make holes in the beams for structural buildings. Basically it's an electromagnetic drill press.

 

[LowRiver2]

Cutting torch or a plasma cutter lol...wouldn't be a good idea with what you do, but want to talk about getting in there quick.

Milwaukee makes a cordless mag drill, that's what you guys should be looking at. It will make a perfect hole, that's what they use to make holes in the beams for structural buildings. Basically it's an electromagnetic drill press.

Yeah, as little heat as possible lol.

The vibration isn’t an issue as move sensitive IED’s won’t last getting banged around in loading on the ship lol.

I’ll check them out.
We have some grant funding projects coming up and breaching conex boxes is one challenge we need to address more with a super bowl, world cup (?) and Olympics coming.

Thanks !

 

[JUSTWANNARACE]

Cutting torch or a plasma cutter lol...wouldn't be a good idea with what you do, but want to talk about getting in there quick.

Milwaukee makes a cordless mag drill, that's what you guys should be looking at. It will make a perfect hole, that's what they use to make holes in the beams for structural buildings. Basically it's an electromagnetic drill press. View attachment 981892

Yeah, as little heat as possible lol.

The vibration isn’t an issue as move sensitive IED’s won’t last getting banged around in loading on the ship lol.

I’ll check them out.
We have some grant funding projects coming up and breaching conex boxes is one challenge we need to address more with a super bowl, world cup (?) and Olympics coming.

Thanks !

Mag drills are awesome!! Makes life so much easier! And way easier on the wrist!

 

[traquer]

Good suggestions here. I remember when my dad first showed me what a step bit was. Blew my mind. It was amazing for large holes with no grabbing (there's no spiral on them to suck them in).

 

[scottchbrite]

Yeah, as little heat as possible lol.

The vibration isn’t an issue as move sensitive IED’s won’t last getting banged around in loading on the ship lol.

I’ll check them out.
We have some grant funding projects coming up and breaching conex boxes is one challenge we need to address more with a super bowl, world cup (?) and Olympics coming.

Thanks !

A magnetic Drill and roto broaches are the shit!! I would of recommend the mag drill but they may not be as tactical. If it’s grant money, spend it, get a bad ass mag drill

 

[TITTIES AND BEER]

Cutting torch or a plasma cutter lol...wouldn't be a good idea with what you do, but want to talk about getting in there quick.

Milwaukee makes a cordless mag drill, that's what you guys should be looking at. It will make a perfect hole, that's what they use to make holes in the beams for structural buildings. Basically it's an electromagnetic drill press. View attachment 981892

My steel guy " Top Steel " uses this , works pretty good

 

[hallett21]

These are what we are issued

Question for all:

Conex containers :

Who has drilled into these on sides and roofs with hole saw bits?
What were the best brands, drills, etc.?

We have to get into them once in awhile at the port for WMD and other stuff to get probes and snake cameras in.
Always looking for better tools for that job.

I’ve drilled them with Lennox hole saws no problem.


Sent from my iPhone using Tapatalk

 

[hallett21]

You can get an electrician set of Lenox hole saws that are designed for 1/4” or thinner steel. They are just shallow hole saws. Perfect for a container.

Sent from my iPhone using Tapatalk

 

[Taboma]

You can get an electrician set of Lenox hole saws that are designed for 1/4” or thinner steel. They are just shallow hole saws. Perfect for a container. View attachment 981907


Sent from my iPhone using Tapatalk

Let me ask you young sparky, have you learned the trick of packing your hole saws for 1/2" to 1 1/4" (Or larger if you like) conduits with duct seal ? If you do, they'll only last forever.

 

[rrrr]

You can't buy real drill bits at Home Depot. If you want performance and longevity, go to an industrial supply and buy an Alfa index set. These two are HSS and cobalt. I've had them for over ten years and they're still sharp. Of course, technique has a lot to do with that.

 

[hallett21]

Let me ask you young sparky, have you learned the trick of packing your hole saws for 1/2" to 1 1/4" (Or larger if you like) conduits with duct seal ? If you do, they'll only last forever. [emoji106]

Tell me more. I assume you mean pack the inside?


Sent from my iPhone using Tapatalk

 

[Waterjunky]

Buy a Viking or Nordic set of bits Start with something like 1/4" and jump to 9/16 if you are using 1/2" bolts. With decent bits, the large hop is still easy. The little bit of play will be worth a ton of frustration.
In a pinch the good house brand at Fastenal are imports but solid performers. There are fastenal's everywhere these days.

 

[JDKRXW]

I see titanium ones? Cobalt ones ?
What type of bit?

I'd get an oxy-acetylene bit.

 

[Nordie]

I'd get an oxy-acetylene bit.

Never leave home without it

 

[Taboma]

Tell me more. I assume you mean pack the inside?


Sent from my iPhone using Tapatalk

Went to the lake for a week which includes unplugging. Yes, you pack the inside of the hole saw tightly with duct seal --- in my day " Monkey shit". Usually leave about 1/4' down from the teeth. Or enough to get a skinny screwdriver in the slot to clear the plug. I scoffed when an old bird taught me this ages ago, but humored him and holy shit the saws seemed to never wear out. I believe the monkey shit acts to absorb and more rapidly transfer heat away from the teeth. Since in our trade we're normally using them for cutting thin metal we don't need the depth. I'm sure it would work on your shallow saws you pictured as well. Obviously wouldn't work on wood working hole saws where the depth is necessary.
In addition to the heat sink properties, as the duct seal heats, it might just ooze a bit of lubrication ?

 

[77charger]

Im just basic harbor freight drill bits but i have had good luck with them when i built my old gate needed to drill about 40 5/16th holes in 3/16 angle iron i did the step up 1/4 inch then 5/16 drilled slow and just shot some wd40 to keep the bits cool.Bits cut good start to finish to my surprise

 

[nowski]

Thanks for all the quick responses. I think I'm running the drill too fast, I'll slow it down.

The problem with too much speed is you work harden the material making an easy job even more difficult. Try using Tapmatic Gold for your cutting fluid, you'll thank me later...

 

[arch stanton]

I use a tapered ream to make holes up to 1 inch it’s like a step bit but better if you have the room behind the hole you need about 6 inches clearance for 1 inch
This does not grab if you are out of position or say on a ladder
They last a long time and will cut through 1 inch thick plate but they really work well on thin sheet like cargo containers
You will have to cut a pilot hole first 1/4 works good them it it with the ream 1 ream covers a few sizes buy a 3/8 , 1/2 , 5/8 , 3/4 and 1 and you are covered for almost any situation they do make smaller ones that are handy it but usually you just drill the size you need the first time and they do go larger but better to use a carbide tipped hole saw or annular cutter when you get bigger but if the material is thin it maybe faster.
I have a mag drill also but they do not hold onto thin metal as well may not work on a shipping container

 

[arch stanton]

First pic is tapered reams

next pic is plasma cuter stencils

3 rd pic is carbide tipped hole saws regular hole saws , annular cutters and 2 adjustable reams

or we can go old school big drill bits

then we have all the rest of the drill bits

 

[Havasu blue label]

That’s the shit great sets

 

[Havasu blue label]

Need to get my lazy ass off this couch and organize my shit

 

[DLC]

I have a set of these pilot points and they work really well

might be worth trying out one or 2

 

[NicPaus]

I have a set of these pilot points and they work really well

might be worth trying out one or 2

View attachment 984184

I used these last week to drill my conex and then Sawzall to make the holes for the whirly bird vents. Used some oil and it helped.

I had to make 80 holes in some angle iron. After a few drill bits I bought a plasma cutter.