drilling large holes on 3/16" steel

[latinoguy]

Besides a Drill press.....(don't have one) what is a best practice for drilling 1/2" holes on metal up to 3/16" thick?

Can a corded 1/2" drill be up to the task with a good quality drill bit?
Use "cutting oil" as well right? start with a small diameter drill bit and go up right?

[zebrabeefj40]

Everything you said is exactly what you'll need to do. Make sure you clamp the piece in a vise or to something sturdy too. Watch out for the 1/2" drill. If the drill bit grabs it'll spin the drill outa your hands (broken bones can be the result).

Nick

[3_puppies]

1/2" drill works fine, use the extra handle for better grip. 1 small pilot hole and then a nice sharp 1/2" drill bit good to go.

[flintknapper]

Originally Posted by latinoguy

Besides a Drill press.....(don't have one) what is a best practice for drilling 1/2" holes on metal up to 3/16" thick?

Can a corded 1/2" drill be up to the task with a good quality drill bit?
Use "cutting oil" as well right? start with a small diameter drill bit and go up right?

You've got it.

If you have a drill bit "set"....start with 1/8" to place your holes. If the holes need to be exact, use a punch to make a dimple to start your first bit on.

For mild steel up to 1/4" thick...I'd jump up to 5/16" for my next bit...then finish with 1/2".

As someone already mentioned...be careful with the half inch drill, they can be powerful.

If the drill bit "bites" and spins the drill, your tendency will be to grip the drill harder, which keeps the trigger down, which only makes things worse.

[sk8salomon]

you might be able to rent a portable drill press at a local shop. many have a magnetic base and 110vac motor. that would be much better to control hole accuracy and safer for you.

[Cruiserdrew]

The safe way is a little at a time. 1/8, then 1/4 then 3/8 then 1/2. I can strongly recommend a step bit, which will do this for you. Use the step bit that ends at 1/2 and you will get perfect holes with little risk. Cutting fluid like "Tap-Ease" is good too.

Even for larger holes, I tend to use the step bit-it cuts very clean holes with much less muscle. For a 5/8 hole for instance, I might use the step to get to 1/2, then a 9/16 then a 5/8. It sounds like a lot of bit changing, but it is way easier in the end. Always cut a pilot hole-that way your cheapest bit is doing hte hardest job. It preserves the sharpness of the larger and more expensive drill bits.

I was using a 3 inch hole saw on my front cross member and it bound up and nearly tore off my hand. My wrist hurt for 2 weeks after that. Bottom line-even portable drills are surprisingly powerful.

You could just buy one of those bench top drill presses.

[CRZA1]

step bits, step bits, step bits. I have had great luck with these. They cut cleaner holes and seem to stay sharper longer. With thick plate you may have to drill from both sides.

[gladly]

Originally Posted by CRZA1

step bits, step bits, step bits. I have had great luck with these. They cut cleaner holes and seem to stay sharper longer. With thick plate you may have to drill from both sides.

yep, but do the pilot with a 3/16 bit, (the double ended ones work great) to save wear and tear on the step drill, cause they're pricey

[Arya Ebrahimi]

And buy your step bits at Harbor Freight. You can get a 3-pack(various diameters and step heights) for around 8 or 9 bucks, as opposed to one from Home Depot for $30-60. And yes, they actually hold up pretty well.

[splitshot]

Originally Posted by zebrabeefj40

Everything you said is exactly what you'll need to do. Make sure you clamp the piece in a vise or to something sturdy too. Watch out for the 1/2" drill. If the drill bit grabs it'll spin the drill outa your hands (broken bones can be the result).

Nick

Yep, I can just start to shake hands again without grimmacing. Broke mine last April.

I bought a press shortly thereafter..

[colangut]

Try these:

Eastwood Co. - Small Hole Cutter Kit

They work amazingly well.

You can also get a small drill with a clamp on it to fix to the work with out a drill press.

My welding shop (Arcet Equipment in Manassas Va) sells them individually, check ebay, etc.

I also have a drill doctor and it's equally amazing how well a sharpened bit works!

When I worked for Black & Decker / Dewalt, they told me a guy had been killed by a large spade handle drill when he was drilling on a roof with the drill between his legs. When the drill but stuck, the drill twisted and the guy was thrown from the roof. True story? Who knows, but the point is a large drill can be dangerous.

[NTAPHSE]

Here's another vote for the Harbor Freight step drills. Get 'em on sale for $9. I swear I hardly ever use my drill bit index since buying step bits. Another adavantage to them is that the next step up automatically deburrs the hole for you. Also use a center punch to start the drill right where you want it, and pay attention to not let it wander on you. I use motor oil as a cheap cutting fluid.

[the truck doctor]

1/4" pilot hole the use a reamer bit to 1/2"

[D'Animal]

The larger diameter you go the slower you want to turn your drill bit.

Small bits work fine when spinning fast. Large bits tend to overheat when spinning fast. This is the demise of many large drill bits.

I have blued many step drill bits because I did not slow down when going to the large sizes.

[Blue 60]

Seriously. Take it to a metal fab. shop and have them punch the holes. As long as the holes are in plate or flat bar, get them punched. If it is in a frame or tube, then what everyone else says. I spent two years working in a metal fab. shop while going through college. Iron workers (the machine, not a person) are a great tool. Typically you can punch as thick as the dia. of your hole and we had a 2 1/2" punch for plate up to 1/8". (80 tons of pressure) Just my $.02.

Blue 60

[latinoguy]

Recap
The fabricator (Russell at CV Off Road) and I used a drill press and a step bit at the end to get the right diam size to drill the plate holes...Then we welded the outriggers to the plates once the plates were mocked fastened with the Ubolts etc.

The project turned out good and I did a write up on the 80s section.

Something for me to think about..The Ubolt legs are longer than what I specified and makes for using a deep socket difficult (tight working areas)
Q: any way of cutting the ubolt legs witouth affecting the thread patterns?

Also,

I have been thinking about a future mod that I am doing...(Rear Tire Carrier ala WildOats & Zane) and will have to get as many metal tools (no plasma and welder) and do as much of the work myself)
so with that said, Yes a Recriprocating saw does work on cutting steel plates as think as 3/16" and 1/4" (I've shortened the Skid Plate by 5 inches....and used my Dewalt 18V recip saw with a metal blade and the cut turned out well, smooth and straight.

Browsing thru craigslist I can pick up a used band saw for about $100 (craftsman) or a Ryoby/Craftsman Chop saw for $50. Not bad...I may have to buy one of the two...What should I look, besides capacity for a band saw that can cut 3/16" Box steel and steel plate?

Another Q, since I am on the subject...Can an arc welder provide (for this future project) as good a weld as a MIG welder? I need some schooling on the weld strenghts differences between the 2....

Oh, thanks again for all the good advice...nice tip on the harbor freight step drills. That is a cheap price for a cheap drill bit that won't see much use...

[-Spike-]

Originally Posted by latinoguy

Something for me to think about..The Ubolt legs are longer than what I specified and makes for using a deep socket difficult (tight working areas)
Q: any way of cutting the ubolt legs witouth affecting the thread patterns?

Yep. Hack 'em off to whatever length you like, then clean up the end of the thread with a file or grinder. Just taper the end of the bolt. You can make it easier by threading a tap or nut on the bolt before filing/grinding, then when you remove the tap or nut it will straighten the end of the thread for you.

-Spike

[AlaskanWheeler]

As far as the durability and strength of your welding method, both would be equally the same strength, for our type of application.