Well, so much for Dewalt metal drill bits...

[treimers]

Well, I've discovered that DeWalt cobalt metal drill bits
do NOT work in metal... except to melt down..


I bought this drill bit
http://www.dewalt.com/tool-parts/dr...g-cobalt-pilot-point-drill-bits-dw1220-g.aspx

DW1220 Industrial Drilling: Cobalt Pilot Point Drill Bits
Product Features
•Maximum speed & Life in stainless steel and other hard metals
•Pilot Point® tip desgin starts on contact and eliminates bit walking
•Industrial strength Cobalt for optimum life & durability in metal


Purchased from a certain well known hardware store.

Looked like just the trick for drilling 5/16 mounting holes
in some recovered chunks of bedframe.
(making new fence guide rails to extend a table saw deck, trying NOT to buy
expensive new materials, and economically save stuff from filling up the landfill)

I was using a Delta drill press with a DP vise, everything clamped down,
dribbling water onto the site to keep from overheating the drill bit.

The attached image shows what happens when you try to use
a DeWalt "metal" drill bit on actual metal...

 

[treimers]

So does anyone have any suggestions for how to drill those 5/16 holes
without investing in a $60 drill bit?

 

[lotsoftools]

Perhaps your drill was spinning too fast? Or maybe your choice of water instead of cutting oil?

 

[Mohawk Dave]

Appears you had no pilot hole. A 3/32" pilot will save bigger bits from doing the point cutting. EDIT: 5/16" = no pilot in DP.

In the field the other day I used Delo 400 motor oil as lube/cool...worked great. (all i had on me)

Name brands...Norseman, Guhring, Precision Twist Drill, Dormer..

In general, for most ferrous metals,

small diameter drills = high speed, low pressure
Large diameter drills = low speed, higher pressure

EDIT 2: looks as if it got too hot. You can really soak that when drilling. No dribble, just drenched.

If you want to learn....
http://www.norsemandrill.com/Drill_Troubleshoot_Face.html
http://www.norsemandrill.com/Feed_Speed_Face.html

 

[Zrexxer]

First off, yeah. As you've discovered, DeWalt bits aren't much use on steel.

Secondly, bedframe is the worst kind of **** to work with. It is hard and difficult to work. A lot of bedframe is manufactured from recycled railroad rail. This is one place where being a scrounger is causing you more problems than it's worth.

Finally, any HSS twist bit should be able to handle 5/16 holes. Water's not what you want to use for drilling. Use a cutting fluid, or a light oil, drill slowly and evenly, and keep pressure on the bit and keep making chips. If you let off the pressure and the bit starts to spin you will create a localized work hardening in the material, the cutting edge of the bit immediately becomes ruined, and you're done.

Drill steady and keep the pressure on.

 

[Trucky]

First things first...

Water isn't... proper. But I suppose it wouldn't hurt. Drill bits still aren't really supposed to do that. As a rule (for bits and all cutting tools), gimmicky stuff is never that great.

Also, I'm going to imagine that steel isn't very weak either. Take your time. If you're doing everything else right, a proper drill bit is really the only solution:

MSC 5/16" drill bit

Stick to HSS and you should be okay. I'm used to solid carbide now but high speed is sometimes the ticket (especially in "rough" materials or ones that "grab").

Also.. I have to ask: Were you peck drilling or just trying to go right through it? Honestly I've never seen that happen without someone trying to lean into it the whole time. Also compounding the problem could be the lack of a pre-drill/center drill.

 

[theknurl]

treimers;
there is nothing wrong with the drills.....

1. you need to use cutting fluid......never ever heard of anybody using water.....if nothing else, it'll rust the drill press and vise

2. slow the spindle speed down

3. bed frames are made from the worst steel salvaged.....try welding it

 

[Chaznsc]

Maybe too much downward pressure? And you used water? I think id use some kind of oil.

 

[lotsoftools]

I've been using these with good luck: http://www.fastenal.com/web/product...rd=&rfqId=&rfqLineId=&zipcode=&filterByStore=

Even through bed frame. No pilot hole, just slow speed, steady pressure and cutting oil.

 

[dadsEH]

A good tradesman does not blame his tools. So you stuffed up.... **** it up!!

 

[neophyte]

Where was that drill bit made? Older Dewalt bits were made in Germany. My understanding is some of the newer drill bits have had their production shifted to China. I've seen complaints about the newer Chinese drill bits Dewalt and other manufacturers are offering. If the drill bit was made in Germany it should say so on the shank. As far as the Dewalt Pilot point drill design it's specifically designed so you don't need a pilot hole. I have an older German set in regular HSS with an oxide finish that I like. I don't routinely drill hard steel with them so I can't directly compare.

 

[Coach James]

I heard Dewalt bits are pretty good. You could try some of them and see how they do.

Coach

 

[neophyte]

A good tradesman does not blame his tools. So you stuffed up.... **** it up!!

Tradesman have been blaming their tools for centuries or longer. Sometimes the tools are actually at fault. I'm sure there were craftsman in ancient Egypt who complained when a stupid arrogant foreman supplied them with the wrong type of stone for their rock hammers and chisels.

 

[Stephenw]

Last time I looked, DeWalt was peddling Chinese drill bits.

In my experience, bed frame steel can be extremely hard. It can be rough even with a quality bit.

 

[OccupantRJ]

My first mistake as a teenager was selecting bed frames for a fabrication project. Once, and only once.

 

[Doug Arthurs]

Bed frame material is as mentioned hit and miss. Don't weld any projects with it that could hurt someone if a weld fails. I have had perfectly good looking welds fail in bed frame. It seems to become very brittle and a chunk of material near the heat affected zone will fail sometimes. Also as you found out it can be brutal to drill. Try using a masonry bug on it if you can sharpen the bit first at 118 degree point. Then use lots of cutting fluid.

 

[CWP1616L]

So does anyone have any suggestions for how to drill those 5/16 holes
without investing in a $60 drill bit?

They're gonna cost more than the DeWalt bits but I don't think quite $60. If you want the good stuff, always go to an industrial supply; whether it be local or online.

 

[treimers]

Wow, thanks for all the fast replies, guys (and gals, should any of you happen to be of the fairer gender)

I appreciate all the info (and links)

I used water because that's what I had -- knew I'd need something.
I'd have used motor oil, but I was afraid it might burn.

To answer the question one or more of you had
I started off using steady but not super-hard downward pressure, was making chips nicely.
I don't know if it skidded and created the hard metal area at some point-
but yes, things got way out of hand fast after a certain point, so I quit.

Overall, though, I'm getting the message about the crappy hard-to-work with steel involved in this thing.

Given that I was planning on making a better fence later on anyway, and might've been trying to remodel the rails still further,
I think it's time to shift the plan to readily available bar aluminum of some sort, and just cut that down as needed.
It will be a _lot_ easier to work with ;-)


Appreciate all the information!

 

[cheechi]

I have that dewalt bit set and I've only used it thrice. Twice the 3/8 and once the 1/2, all in plate steel. The bits still look brand new. Once it was on a DP but the 3/8 holes was a 18v drill. I didn't have 'real' cutting fluid so I used WD40 (it's everywhere for some reason).

I want to say all of it was 1/4" but it may have been smaller. There are better bits out there but if you do it right, those bits wont look like that.

 

[Strouty]

Wow, thanks for all the fast replies, guys (and gals, should any of you happen to be of the fairer gender)

I appreciate all the info (and links)

I used water because that's what I had -- knew I'd need something.
I'd have used motor oil, but I was afraid it might burn.

To answer the question one or more of you had
I started off using steady but not super-hard downward pressure, was making chips nicely.

Sounds like it was too fast for the DP speed. Ideally you should have a spiral not chips. I have no experience using bed frames, but sounds like they are part of the problem. Was that bit originally stepped? If not you really made a mess of it. Also I have used water on drill bits before, it is not ideal, but it is better than nothing. It was actually snow that we used, someone forgot the cutting oil and the nearest store was hours away. We ruined one bit before the snow, after using it we had no more problems.

 

[neophyte]

Sounds like it was too fast for the DP speed. Ideally you should have a spiral not chips. I have no experience using bed frames, but sounds like they are part of the problem. Was that bit originally stepped? If not you really made a mess of it. Also I have used water on drill bits before, it is not ideal, but it is better than nothing. It was actually snow that we used, someone forgot the cutting oil and the nearest store was hours away. We ruined one bit before the snow, after using it we had no more problems.

The Dewalt Pilot point drill bits are stepped. The design is sort of like a brad point drill bit but for metal. The "pilot" point is designed to start easily and get the hole in the right place and then use the flatter step to drill the rest more easily.

 

[ez-duzit]

The Black & Decker (?) piloted bits have performed well for me though they are virtually impossible to resharpen. My go to bits are made by/for Milwaukee, both HSS and Cobalt. As has been mentioned: use the correct rpm, lube it, and keep it sharp. Stop drilling if it stops cutting.

 

[greasemonkey44]

bed frames are hell to drill; they can be insanely brittle which makes them so hard to drill
ive shattered brand new bits trying to drill through; most of time you have to heat it up cherry red and anneal it(let it cool), or resign yourself to losing some bits
usually you can buy normal angle iron pretty cheap anyway

 

[jakemac]

I consider all my drill bits as "disposables". I buy inexpensive hardware store bits as sets or singles and don't worry if they break or dull. I just grab another one. I keep several spares of the ones I go through the most on hand to get me through the project I'm working on and replenish the next time I hit the store.

I try to keep the edges sharp to save money, but I figure that there are some tools that will wear out sooner or later no matter what I do. In those cases, I buy cheap and don't sweat it.