What's the secret to drilling through 1/4" angle iron?

[swines]

You would do yourself and your drill bits a favor by buying cutting fluid. Cutting fluid is different than lubricating oil, and in fact, lubricating oil can impede a drill bit from cutting easily because it has anti-friction, high pressure additives that keep a fluid film between the metal and drill bit cutting edge. This keeps the drill bit from cutting easily.

Cutting oil has sulfur as the lubricant and some include chlorinated paraffin lubricants. Cutting fluid allows the chips to slide away which would otherwise generate heat. It's formulated to not stick to a heated surface and pass away with the heat unlike a lubricant.

I use LPS Tapmatic #1 Gold for steel. I have a PVC 2-inch diameter end cap that I fill with the cutting fluid and feed onto the drill bit with a flux brush as I'm drilling. If you're using a hand drill, then I'd brush the drill bit and stop 2-3 times during drilling to clean the chips out of the cavity in the steel, and fill the cavity with cutting fluid.

If you haven't used cutting fluid, you'll be surprised at how much easier it makes drilling holes.

 

[SIMassey]

I have to drill 40 quarter inch holes through 1/4" angle iron with a hand drill. I've tried most of the different drill bits that Home Depot sells and they usually get too dull to drill after 2 holes.

Is there a better drill bit I can buy or am I doing something wrong in the way I am drilling?

Angle iron is normally high in carbon which gives it its toughness and ability to flex without bending. Too much speed is your worst enemy. 612 rpm would be my recommendation of maximum speed for a 1/4 inch drill. Thinning the web of the drill would reduce the pressure required to push the drill and 135 degree included point angle along with proper relief on the back side of the cutting edge. There is a real science to proper drill sharpening. The drill doctor is your best chance if you are not trained to sharpen them by hand on a pedestal grinder.

 

[DuckSlayer1017]

For lube, cutting oil is best but if you don't have any use the heaviest wt oil you have when cutting steel. A couple months ago I had to do about 30 holes in 1/4' flat stock. When I was done I told my wife I was getting a drill press for fathers day. Don't be like me, get the drill press first.

 

[chim]

As mentioned, the right combination of speed and pressure helps a lot. I joke that many of our guys get no benefit from the variable speed drills we have. They just mash the trigger all the way. When they drive screws and want to slow down for those last few turns, their method is mashing the trigger all the way in short bursts.

 

[4570Man]

I'd use my milling machine, but a drill press would work. Turn the bit slow. I can turn as slow as 40 rpm ( 14 if I use the lathe ), but I would start about 500 and see what happens.

 

[boggen]

i am not a big fan of "drill press" were you take a regular 110v corded drill and place it into some holders, and use it like a drill press. they seem to flimsy. and trying to get drill bit lined up can be troublesome.

get yourself a regular drill press that has variable speed or different belt option / pulleys for different RPM's.

it is nice to have a built in light in the drill press. to many shadows from other lights and hard to read your pencil marks or like at times.

clamp your work piece to the drill press little table. i have used C clamps, to different types of vice grips. to pipe clamps, to other. normally min of 2 clamps (one on each side) to hold piece securely.

i have cut up a 2x4's in table saw and chop saw for various thinks to make a holder for drilling holes in pipe.

i have also tossed say a 2x8 chunk of spare lumber between the drill press table and piece i want to drill. so i do not drill down through the drill press table.

drill press + lubricant for metal = a large mess. i find it easier to have drill press out and away from wall's so i can clean up afterwards.

double check "chuck" on drill bit every now and then. most of the times i get things good. but some times the chuck will come loose and cause the drill bit to wobble about *big ugly frown*

 

[tallyho8]

To clarify, I am drilling holes in the sides of a trailer so I can not use a drill press. I have to drill horizontally so any type of cutting fluid will run out of the holes rapidly. I have some new cobalt drill bits I am planning on using.

I can use either a 110v Hitachi variable speed drill or an 18v Craftsman on hi or lo speed. Is a continuous water spray any good as a cooler/lubricant, or a heavy oil or do I really need a specialty cutting fluid?

 

[4570Man]

Check how much it would cost to rent a magnetic drill. The craftsman probably has more torque if you have to do it by hand.

 

[JIGBUILDER]

As my user name says I was a aircraft jig and fixture builder/tool maker for 40 years. While out in the plant away from our shop all holes had to be drilled/reamed/tapped by hand. Drilled or reamed or tapped holes up to 1" diameter was done by hand usually with a drill block for 1/2" and up. All reamed holes were done with a drill block to keep the hole inline. Material thickness could be as much 3" thick steel and /or aluminum. This kind of work is exhausting on large fixtures that may have 100-200 3/4" bolts a twice that amount of 1/2" dowels.

I like a #10 118 degree split point high speed drill to start with when done by hand. I have lots of #10 piloted 1/4" drills to step on out. I've used a 135 degree kobalt drill for the final step up also but they can grab when first used till they get a bit dull then they don't grad if you take it easy. I also use a #10 piloted 1/4" core drill. With 3 or 4 flutes they won't grab like a two flute drill.

I find 135 degree kobalt drills a pain to start with but do a better job of stepping on out. These drills don't have as much relief ground in which makes them darn tough and don't break the edge as bad.

For that many hole you might check into renting a electric mag base drill motor (Bux or semilar brand) and let it do all the hard work. We used them also and work great while 15'-20' in the air hanging on the side of a large jig. The mag base holds the drill in place and work great for drilling 3/4 -1" holes and even tapping them. If we were working on a aluminum fixture we simple C clamped a 1/2" steel plate for the mag to clamp to. Just make sure someone doesn't unplug the electric cord .

 

[boggen]

look up in the old "paper phone book" not internet. for "equipment rental" or "machinery rental" some of the bigger local hardware stores (menards, home depot, lowes) might have something better....

low tech, i have used something like... Milescraft Rotary Tool Drill Press Stand Model 1097-10970003 - The Home Depot
google "drill press holder" or "drill press stand"

see if the base will twist 180 degrees. and clamp the base on to trailer. or clamp base to frame of trailer. and let the drill bit go straight through the "center hole" within the base. into the frame work.

other words instead of clamping something to the drill press, clamp the drill press stand to what you are work on.