Drill bit navigation...

[DeniseO30]

Cobalt, 135°, split point? Carbide, every time I've tried to drill steel from simple angle iron to stuff on the truck or car I've had nothing but failure. I'm sure I, like many others have wasted $$$ on Big box store yellow.

McMaster-Carr is my go-to for industrial quality.

Is it really true you can't use carbide drill bits in a portable drill ( breakage) and true Cobalt drill bits are the better choice?

I'm ready to throw out the shoe box plastic container of drill bits that'll probably never use or sharpen, although I've tried,

This could very easily be a marine engine requirement so I'm not too far off tools and boats topic.

I just know I'm going to be tasked with finding drill bits when I get help to do the clutch on my truck,. I do have a low speed right angle whole hog type drill but I don't have a magnetic drill press that wouldn't work anyhow on things like manifold bolts,


torch is out of the question because the gas line, evap canister are very close to the manifold connections, I would love to have electric induction bolt heater but can't justify the cost,

So I'm on that never-ending search for the "perfect" drill bits

"Kroil" is on the the list also

[Canoeyawl]

As long as it is "high speed steel" any H.S. drill bit should do the job. Drilling is more about speeds and feeds than the actual bit itself, assuming the bit is sharp.

Note that 100 s.f.m is a good safe (conservative) number for drilling regular low carbon steel with a hand drill, and 30 s.fm. is a good number for stainless, and high carbon steel. (You must be pulling a chip to prevent the cutting edge from overheating. This requires more pressure than one might suspect. The "chip" takes the heat away from the work. No chip = no good!)
*Note that s.f.m. is the circumference of the drill bit in feet, times the rpm (and a little cutting oil goes a long way)

[DeniseO30]

That i've never been able to press hard enough is the fail? Guess bungee cords will help! But I've had new bits drill nice at low rpm for a few minutes then.. in the box they go!

[ShorelineJohn]

I am no expert, but I always have said oil,oil, and more oil. Too much makes a mess but not enough causes lots of problems.
3 corner holes is what I seem to fight the most, which is speed, force and material.
Just not sure why you need a drill bit to change a clutch.

[GregH]

You didn't mention what the size of the finished hole is to be, but when using an (electric) hand drill in steel, anything over 3/16" should be started with something no bigger than 1/8" and work up to finished size in 1/8" increments. As mentioned above, plenty of pressure (but under control) and a bit of oil never hurts!

[DeniseO30]

Y pipe, transmission won't go over it

Yes I thought that was common knowledge that we start with a small hole and work up to larger holes but again Big box store drill bits are worthless.

[SchoonerRat]

Drilling steel requires low speed and high pressure. My biggest problem has always been breaking bits because with a hand drill it's difficult to get the pressure perfectly aligned with the bit. You'll have better luck if you have the room to use a guide to keep your bit straight.

46441-04-1000.jpg

Not enough room...a small block of wood drilled on a drill press can be used as an effective guide.

Even better, get your drilling done on a drill press if it's possible.

[John Meachen]

You didn't mention what the size of the finished hole is to be, but when using an (electric) hand drill in steel, anything over 3/16" should be started with something no bigger than 1/8" and work up to finished size in 1/8" increments. As mentioned above, plenty of pressure (but under control) and a bit of oil never hurts!

I always use something at least large enough to let the central web pass when the full size hole is drilled.Decent quality HSS never seems to let me down and I have used TiN coated with no apparent advantage.Its a good idea to stop before the blunt drill begins to work harden the piece being worked on and pay a visit to the grinder.

[Larks]

Try stepped conical drill bits and use a decent drilling/cutting compound

[Dave Hadfield]

If you dig and see the old films about gang-drilling V-12 engine-block stud holes during WWII, what strikes you (me) is the high-volume flood of cooling oil immersing the platform. Smothering it. Covering it.

You need to cut, and never ever abrade.

[Canoeyawl]

For real production work, drill bits will often have coolant passages right in the bit itself.
I used to work with Swiss screw machines, and they ran with flood coolant, several lines directed at each specific operation. In fact all production machining uses coolant/cutting lubricant.
Fwiw, the most basic type cutting oil is lard based, rather than petroleum, motor oil is not really the right stuff, but in a pinch it is maybe better than nothing.
Just get some cutting oil and keep it handy. It will reduce the pressure required to cut a chip. Typically the more expensive the better it works.
For most steels the cheap stuff will work, for the more exotic Stainless steels, aquamet, monel and etc I use Moly-Dee, but it is frightfully expensive. But some hardened or "tough" materials are almost impossible to machine without it.

Home depot has the most basic type in a pint with a spout, which is fine for almost everything.
https://www.homedepot.com/p/Oatey-16...2032/203461243

[bluedog225]

I needed to drill a holes in 5/8 and 1/4 cold and hot rolled plate. Finally bought a decent step bit. $50 or so. Worked great. Even freehand on a most of the holes. It died after about two dozen uses. Suspect it would have lasted a lot longer on a press and with somehing other than water lube.

DD9F29EB-3EB6-483A-837E-EBB578E13C70.jpg

[cyclone]

I use cobalt because of 316 stainless but I also use a set of Rotobroaches, even with a hand drill. They are good to 1/2” thick material. Anchor Lube is a good cutting medium. There was a time when you could get free promotional samples.

[oldsub86]

"torch is out of the question because the gas line, evap canister are very close to the manifold connections, I would love to have electric induction bolt heater but can't justify the cost"

Lots of information on the web about how to make your own induction heater . . .

[upchurchmr]

Denise,

I've never had to drill out a clutch in about 15 replacements.
Do you remember the old rime - righty tighty, lefty loosey?

How about an impact driver?

What are you expecting to break?
Removing the bell housing, mounting the clutch plate or removing the flywheel.

By the way, what manifold? The intake manifold?

[bluedog225]

Never heard of Rotabroach. thanks!

[DeniseO30]

Denise,

I've never had to drill out a clutch in about 15 replacements.
Do you remember the old rime - righty tighty, lefty loosey?

How about an impact driver?

What are you expecting to break?
Removing the bell housing, mounting the clutch plate or removing the flywheel.

By the way, what manifold? The intake manifold?

Drill a clutch righty tighty... huh?

Bell housing is cast as part of the transmission on the Ford M5OD manual transmission

it's the y-pipe to manifold bolts, the pipe lays across the cross member. It has to be removed.

it's a recurring discussion Ford ranger explorer forums

[DeniseO30]

So I took out the shoe box of drill bits and the drill doctor and started on the larger bits very few after sharpening would cut a piece of angle iron at the drill press so my assumption is those bits have been overheated burned even though they felt Sharp would not cut even with a pilot hole,
Good news, some are excellent and start cutting immediately,

[Ron Williamson]

Show a picture of a sharpened bit.
High speed steel (HSS) should tolerate overheating and still cut.
I would suspect that there isn't enough relief(clearance?) angle so the cutting edge isn't touching.
R

[cyclone]

If the angle iron happens to be bed iron it can be difficult to drill under any circumstance.

[John Meachen]

If the angle iron happens to be bed iron it can be difficult to drill under any circumstance.

Seconded!

[DeniseO30]

Seconded!

Like bed frame angle iron? why would that be hardened? Still none of this really helps me if we have to drill while someone's laying on the ground pushing up.

My drill press lowest RPM is 500

I really don't think the drill doctor I have (which is really old) was even worth it when I bought it new, it's the number 350 model.

[John Meachen]

I have no idea why some of the stuff is so hard to drill,but have found it to be so.A smallish pilot hole and some cutting fluid may be helpful.

[DeniseO30]

The piece of angle? was from the bed frame!

Got a piece of half inch round pipe nearly every drill bit drilled into it

Who would have thunk?

[Ron Williamson]

D'oh!
Bed rails are pretty tough.
They can be pretty hard to weld,too.
R

[Canoeyawl]

Bed frames are high carbon steel to take cyclical loading, (and they can use lighter/less material) You can often spot higher carbon angle and structural iron because for a given size the section is typically thinner. I use this material to build trailer frames, again for cyclical loading or preventing fatigue degradation. A36 structural steel does not make a good trailer...
Older bed frames can also be wrought iron, but either way it will have enough carbon content they will harden locally in a few seconds of dwelling with a drill bit. The heat will do it, you should use coolant and must pull a chip.
(Mild steel is basically non-hardenable without adding carbon. Carbon content is only .18-.25%)

[DeniseO30]

I'll say again... who would have thunk!

I'm sure I'm not the only one with more than one bed frame laying around the house this certainly has been a learning experience about bed frames!

[Paul Pless]

to take cyclical loading

lol

[Bill Perkins]

I've been reluctant to try drilling 1/4 inch a36 steel with my tools ,but having read this will give it a shot .Thanks for all the info .

[DeniseO30]

Well after playing around with these drill bits I've determined I can grind the larger ones and they work reasonably well.

The really small ones just don't seem to get sharpened correctly with the drill doctor. So maybe I'll just buy some small Cobalt drill bits for starter holes.

[woodpile]

From programming NC machines for aerospace components feeds and speeds are a big part of drilling, one of the big mistakes in drilling with high speed steel/cobalt drills is too high RPM that can generate too much heat to a point of removing the hardness from the drill bit, if the metal chips come off blue slow down the RPM.

[DeniseO30]

From programming NC machines for aerospace components feeds and speeds are a big part of drilling, one of the big mistakes in drilling with high speed steel/cobalt drills is too high RPM that can generate too much heat to a point of removing the hardness from the drill bit, if the metal chips come off blue slow down the RPM.

I'd venture to say, if the chips are coming off blue it's already too late which is probably 80% of the drill bits in the box (not all by me).

[DeniseO30]

Well I've pretty much decided to Chuck the drill Doctor 350 which is pretty old but it doesn't seem to work very well to me.

I'll probably get one of these. After watching a few videos.

it's pretty basic and works with just about any type grinder is only around $25
https://www.amazon.com/General-Tools.../dp/B0002YOQ8Q

[willin woodworks]

You're better off buying $25.00 worth of drill bits. General Tools makes crap. You'll be disappointed.

[Garret]

Well I've pretty much decided to Chuck the drill Doctor 350 which is pretty old but it doesn't seem to work very well to me.

I'll probably get one of these. After watching a few videos.

it's pretty basic and works with just about any type grinder is only around $25
https://www.amazon.com/General-Tools.../dp/B0002YOQ8Q

I've got a 20+ YO Drill Doctor - not sure of the model, but it's up in the barn - and it does fine. On smaller drills it's finicky lining it up right, especially with eyes (like mine) that ain't what they used to be.