What do I need to drill into this steel?

[jake00]

I'm replacing the wood deck on my flatbed. I need to drill 9/32 holes. every bit ive tried wont touch the metal. It just powders up. I've tried dewalyt, milwaukee, bosch, metabo All say for metal. I'm going slooooow and using cutting oil

What do I need to get?

 

[nicks78camaro]

I'm replacing the wood deck on my flatbed. I need to drill 9/32 holes. every bit ive tried wont touch the metal. It just powders up. I've tried dewalyt, milwaukee, bosch, metabo All say for metal. I'm going slooooow and using cutting oil

What do I need to get?

Never had any issue with my Cle Lines or Milwaukee Titaniums, and I'm no expert, but I would start by drilling through with a smaller 1/8" bit and work your way up to 9/32". Or maybe a step drill bit. Slow and oil is good.

 

[T VETTE]

I agree with nick, start small and work your way up. Yes it's going to be a process for sure.

 

[MJD1]

5/16" floor screws? I use a 17/64" bit for those. Problem is that rusty scale is ruining the bit before you start. Needle scale or grind the scale off where you want the hole. I use either Viking or Norseman black and gold bits with lots of pressure and usually use the CRC cutting oil.

 

[nadogail]

Small Hole First, follow with a larger size. If you are drilling a.pretty large hole, you may incrementally increase the hole size.

 

[Firebrick43]

Are you going the correct direction and putting pressure? I beams are not high carbon steel and I have never had issues drilling holes any of my fathers trailer and truck fleet. I don't know how many 25lbs boxes of torx trailer flooring screws I have put growing up. Never used cutting oil or ground the tops of the beams either

 

[jake00]

going the correct direction. in one of those pics, we ground a spot and had the same issue, Will try a smaller bit. N4ever had this issue before either

 

[neophyte]

The steel might be a harder higher strength alloy that tends yo work harden very quickly.
Drills buts for drilling out spot welds tend to be cobalt steel.
A cobalt steel drill bit might be needed.
Another option might be a carbide tipped drill bit made for drilling metal.
Artu makes somewhat reasonably priced carbide tipped drill bits.

 

[PCustoms]

Grind the ****, pressure and the proper speed (likely fast then you're using) and it should drill.

That said, damn those look crusty....sure your want to start with something in poor condition?

 

[drokihazan]

Use a die grinder with a flap disc on it to clean the spot first, hit it with a center punch, and use a step-tip drill bit like Norseman Vortex Point or the Astro Turbostep (Matco Hyperstep). Spritz a little Tap Magic into the flutes of the bit now and then. You'll zip through every hole in no time.
Also, lean into the drill, you want steady constant pressure so that you're forcing the drill to bite and cut, rather than just rubbing all over the metal. A $200 Vevor mag drill would work wonders here, super fast and efficient.

 

[RoninB4]

-As others have posted there shouldn't be any trouble using a HSS drill bit on that steel, provided you're in the correct speed range and using an adequate amount of pressure. My only thought would be is the drill sharpened correctly? I've seen brand new drill bits incorrectly sharpened. If the drill bit isn't sharpened correctly it won't cut anything but it can work harden the steel enough to make further drilling very difficult. I wouldn't recommend a cheap carbon steel bit, HSS will be a better choice. If the package (or the bit itself) doesn't state HSS then it's not. When starting a hole you should see a curl of material almost immediately, if not then the drill bit isn't sharp and will just rub the material (promoting work hardening). Using a 9/32 isn't too large for starting, I presume you're wanting a clearance hole for 1/4" fasteners. A 17/64 bit should also work for clearance. I'm not a fan of using carbide tipped drill bits for this application for three reasons:

1) When you break through the other side there's a very real possibility of the bit getting snarled in the material and shattering the carbide tip because carbide is very brittle. HSS is tougher and more resistant to chipping. Cobalt is better still but shouldn't be needed.

2) The carbide tip is usually silver soldered to the steel of the bit. Excessive heat when drilling can soften the solder enough for it to let go and leave the carbide tip in the hole. Now you have a bigger problem getting the tip out of the hole.

3) If/when you do put a small chip in the carbide tip (likely to happen) you won't have a way to re-sharpen it. A HSS drill bit can be easily resharpened with standard abrasives or even a hand held grinder.

-Two ways to gauge drilling speed in steel are to use a spindle speed that makes the flutes just start to "disappear". Faster than that and you're going to burn up and dull the bit. Slower than that requires too much time/pressure per hole. The other visual check is to observe the color of the curls/chips. They should come out silver, if they're yellow or blue then you've already burned/dulled the drill bit. It only takes a moment to burn/dull the cutting edges. I like using cutting oil/fluid when drilling but it's not required. If you're drilling more than 50 holes I might suggest getting two bits. A good HSS drill bit should last for 100's of holes but an application like this one has potential problems. A mag-drill would be easier than leaning on a hand drill but might be a bit expensive for just ONE project. Ease up on pressure a little when breaking through the other side so the bit doesn't get hung up and chip the cutting edges. I'd also suggest reading about how to sharpen a drill bit correctly so you'll never be stuck like this again. When any cutting tool gets dull (they ALL will) you can just do a quick re-sharpen and you're back to drilling again. This is standard procedure in machine shops and not difficult to learn. Post questions if you have any, good luck.

 

[ez-duzit]

I would use a new, quality (made in US), SHORT, Cobalt drill of ~5/32" for the pilot hole. Use high sulfur, pipe thread cutting oil at very low RPM, with plenty of pressure to keep it cutting. Replace the drill as soon as it shows any sign of losing it's sharpness.

 

[PCustoms]

Speeds shouldn't be a mystery, but each time this come up everyone seems to have a different opinion

https://www.imperialsupplies.com/pdf/3660-5_F_Drill_Bit_Sheet_Update.pdf

 

[Dave455]

There is a huge difference between drill bits, even amongst those that are supposedly for steel, and if you do a lot of drilling you soon notice the difference.

Generally speaking, I tend to avoid drill bits supplied by power tool manufacturers. Some are “o.k.” but a lot are barely adequate. I’ve used Bosch, and they were very unimpressive bits.

Try getting a few bits from an industrial supplier. Try maybe MSC, but there are others. I’d probably be happy with a good HSS, but if that didn’t work I’d go cobalt. Crappy cobalt are worse than good HSS though.

You absolutely need to drill a pilot hole first. Start by centre punching (it’s not just to locate the pilot drill, but to allow it to start cutting) then drill the pilot. I tend to use 1/8 as almost a universal pilot hole size, but sometimes you need to go up in steps.

The next problem you have will be getting the stability, and the downforce. If I was drilling that steel I know it would be easy work in a drill press, but without that the drill can wander around, and in honesty it’s hard work to exert the downforce.

I use a big drill if I’m working on steel (the Fein shown below) and even with the stability and weight, drilling freehand is much harder work than with a drill press.



Personally (depending on how many holes need drilling) that job might give me the shove I need to acquire a magnetic base drill. Some of these have chucks designed for annular cutters, but you can get regular bits to fit, and they are all intended for work on steel. In fact precisely that sort of job!

 

[mike93lx]

Since you got useful suggestions already, mine is to buy a mag drill

 

[PCustoms]

Since you got useful suggestions already, mine is to buy a mag drill

Keep in mind this isn't going to fix bad technique (speed) or bad bits

 

[KnurledNut]

I'm replacing the wood deck on my flatbed. I need to drill 9/32 holes. every bit ive tried wont touch the metal. It just powders up. I've tried dewalyt, milwaukee, bosch, metabo All say for metal. I'm going slooooow and using cutting oil

What do I need to get?

I don’t know how you plan to use this flatbed, but bearclaws are a retrofit option that install beside the crossmembers and clamp the decking without having to drill into the steel.
https://thewarrencompany.com/special-products/lowboy-flooring-deck-clips/
https://needatrailerpart.com/produc...FcfQvSwIipaQrsrFQWy_IaH8LiDX8yPHRrk6V6oiEDwQv

 

[mike93lx]

Keep in mind this isn't going to fix bad technique (speed) or bad bits

No, but it's more fun

 

[PCustoms]

No, but it's more fun

I remember the first time I used one.

Overhead, 20' up in a wobbly scissor lift.

I would not describe it as fun

 

[RoninB4]

Speeds shouldn't be a mystery, but each time this come up everyone seems to have a different opinion

https://www.imperialsupplies.com/pdf/3660-5_F_Drill_Bit_Sheet_Update.pdf

-Not criticizing your post (charts/formulas are best) but of no use to someone using a hand drill, mag drill, or even a drill press if there's no way of establishing those spindle speeds with the equipment. It was a good posting.

 

[PCustoms]

-Not criticizing your post

But you did, and the worst part is you didn't even look at it.



On top of that you could look at the side of your drill and likely see and rpm chart.

Not perfect, but gets you close.

 

[RoninB4]

But you did, and the worst part is you didn't even look at it.

-Well I did look at the linked chart and no I wasn't being critical of you. My comment was about applying numbers to equipment that had no way of establishing the spindle speed and guess-ti-mating the speed. Wish you wouldn't get your feelings hurt so easily.

On top of that you could look at the side of your drill and likely see and rpm chart.

-I don't own, nor have I ever seen, a hand drill with a spindle speed chart. Many of the used drill presses I see here don't have a speed chart either. The new ones may have that, so do many of the variable speed industrial floor models but not what most members here have nor would those be used for this application. Stop taking this so personal wouldja?

Not perfect, but gets you close.

-A range of 600, or 1,000 RPM (per your now included chart posting) isn't what I'd call "close". You'll burn and dull the drill bit in a couple of seconds at excessive speed. I said it was a good post that you made so stop looking for a personal attack where there was none. I've let past postings go so why won't you so we can all get along and contribute without getting **** hurt? Please stop it.

 

[neophyte]

This is the reason I recommended the Artu bit above.

I believe Artu might have been the original “multipurpose” bit if this sort on the market in the USA, but Bad Dog tools is now around, and I think offers a wider range of products, including full sets, individual bits, and other drill bit styles and cutting tools.
Bad Dog has also been around for I think a decade or more.
These are not your normal carbide tipped machinist drills designed for high precision drilling on fixed machinery, although the bits may be capable of that.
These bits are routinely demonstrated free hand.

Individual Multi-Purpose Drill Bits

Bad Dog Tools: Find the multi-purpose drill bits you need. Durable, USA-made bits for any job, guaranteed for life. Shop now!

baddogtools.com

 

[Codyboy]

When I redecked my trailer I just used self drilling screws.

 

[stickshift]

Whenever I have to drill anything thicker than sheet steel, my preference is cobalt bits and drill press. Since it seems you have a lot of holes to drill and drill press isn't an option, I would absolutely get a mag drill, especially since you can get a cheap Vevor brand mag drill mentioned earlier (or find a mag drill you can rent). Drilling lots of holes in steel with a hand drill is miserable work, IMHO.

If mag drill is out of your budget, buy it and sell it when done. Maybe you take $50 hit on resale. Saves you a lot of very tedious use of a hand drill.

 

[cannuck]

IMHO 99% of this kind of failure is inadequate pressure, speed too high and lack of cutting oil. I spent years working with electricians who were called on to work on steel equipment and never encountered even one who didn't make all 3 mistakes 100% of the time. Add to all of the above - inability to sharpen bits properly and you have guaranteed failure. You would be surprise how much pressure a 9/32 bit needs (this why many prefer mag drill) but to know the right pressure when you are maintaining a constant chip or curl. If the bit slips at all without cutting the friction rapidly overheats the cutting edge, softening it to dull in seconds. If you do the pilot thing (should not be needed in such a small hole) it must be just over web thickness between flutes of the next and FINAL bit size. Also: drill bits are NOT reamers, so stepping up a size a time will just destroy a lot of bits. Finally: no mickey mouse WD40 spray or such - use proper cutting oil that will stay in place - or have a helper spraying machine shop water based cutting fluid as you drill.

 

[mike93lx]

Make sure you use galvanized or stainless fasteners with that PT

 

[stickshift]

You would be surprise how much pressure a 9/32 bit needs (this why many prefer mag drill) but to know the right pressure when you are maintaining a constant chip or curl. If the bit slips at all without cutting the friction rapidly overheats the cutting edge, softening it to dull in seconds.

Exactly. To do this correctly with hand drill for many holes is a lot of work. Drill press, or in this application, mag drill, controls the speed and never screws it up, and gives you a lot of leverage so you can apply a lot of force without having to exert much force.

 

[Leaflessshadetree]

-Well I did look at the linked chart and no I wasn't being critical of you. My comment was about applying numbers to equipment that had no way of establishing the spindle speed and guess-ti-mating the speed. Wish you wouldn't get your feelings hurt so easily.

-I don't own, nor have I ever seen, a hand drill with a spindle speed chart. Many of the used drill presses I see here don't have a speed chart either. The new ones may have that, so do many of the variable speed industrial floor models but not what most members here have nor would those be used for this application. Stop taking this so personal wouldja?

-A range of 600, or 1,000 RPM (per your now included chart posting) isn't what I'd call "close". You'll burn and dull the drill bit in a couple of seconds at excessive speed. I said it was a good post that you made so stop looking for a personal attack where there was none. I've let past postings go so why won't you so we can all get along and contribute without getting **** hurt? Please stop it.

Too low of RPM is better than to fast, only downside is that it takes a little longer to drill the hole.
Even if RPM is known and controlled you still have feed rate to consider.

 

[Steve_P]

If you are drilling slooow you are going to go nowhere.

 

[neophyte]

If you are drilling slooow you are going to go nowhere.

You could also end ip work hardening certain alloys, which then makes those alloys much harder to drill.
I believe Norseman specifically mentions this with their M7 Magnum drill bits, that the bits are designed for higher feed rates, and speeds to reduce work hardening certain steel alloys, and I’ve seem specific mention in catalogs from years sho mentioning the same thing about certain Cobalt alloy bits.

 

[Wrench97]

Clean the rust off the top of the xmembers, rust eats bits.

 

[whateg01]

going the correct direction. in one of those pics, we ground a spot and had the same issue, Will try a smaller bit. N4ever had this issue before either

What brand of drill are you using? Cheap drills from harbor freight might not hold an edge in anything harder than butter

 

[KwikFab]

I'm replacing the wood deck on my flatbed. I need to drill 9/32 holes. every bit ive tried wont touch the metal. It just powders up. I've tried dewalyt, milwaukee, bosch, metabo All say for metal. I'm going slooooow and using cutting oil

What do I need to get?

Really?

Where are you located? Bring it here and we'll put holes in it.

 

[mike93lx]

What brand of drill are you using? Cheap drills from harbor freight might not hold an edge in anything harder than butter

The first post wasn't very long...

 

[whateg01]

The first post wasn't very long...

Took so long for me to get to the bottom of the thread, I forgot what I read at the beginning! That said, it could be the dewalyt drills looked like DeWalt and fooled op.