Drilling holes in metal?

[gmason]

Hey All, How do you recommend drilling holes larger than 3/4" in metal?? My standard titanium drill bits go up to 3/4", but if I have a 7/8" or 1" hole what do you do? I don't want to go pay $40-$50 for a single drill bit I may use once or twice. These cheesy stone grinding cones don't hardly scratch the harder metals. I've reverted to spending lots of time using a Dremel tool with some larger stones. But there has to be a better way. HELP!!

thanks
gary

 

[mbjacobs]

I just drilled a 3/4" hole in each side of my loader bucket to mount a tooth bar. Used a hole saw, worked great. Bucket is only about 3/16" but I don't think thicker would be any problem. Probably took less than 2 minutes for each hole.

Maury Jacobs

 

[rf33]

I have drilled 2" and larger holes in some pretty thick (1/4 " to 5/16") steel using bimetal holesaws. The trick is to go slow, use alot of pressure, and pelnty of oil to keep things cool. You want to see large chips of metal (hopefully not from the drill bit/w3tcompact/icons/laugh.gif) instead of fine dust coming off of the work.

rf33

/w3tcompact/icons/wink.gif

 

[rf33]

I found this in the latest Grainger Texas Farm Bureau ad.

I think that the discounted price is only for TFB members, but the regular price is not that bad either.

rf33

/w3tcompact/icons/wink.gif

 

[JerryG]

gmason,
You sound like me. What I have been doing lately with the large ones is ; I take a smaller drill and drill around the ID. Then I knock it out with a punch. I then do what you do, I get the dremel out. If you do it this way there is a lot less grinding with the dremel.

 

[Bird]

I do something similar, Jerry; except instead of drilling several holes and then using my Dremel tool, I just drill one or two small holes, then use my little air powered reciprocating saw.

Bird

 

[Von]

Boy you guys are working too hard! If I need a bigger hole than I have a drill bit for I just fire up the torch and have any hole size I want! All though most are bigger than needed and not quite just round. But they don't take much time to make them!

 

[RPM]

A conical shaped charge will do you a nice hole in steel up to several feet thick. Great fun.

(They can be made much simpler than this if you don't intend to launch it at anything!!)

A linear shaped charge will cut whatever shape you bend it into (with some limits on smallest radius) in steel up to several inches thick.

... much in favor with special forces worldwide for rapid entry into buildings through walls etc.

It WILL wake up the kids if you try it in the garage after bedtime though!!!

Patrick

 

[PBMAX]

I used to use a UNI bit when a did Electrical work...The titanium ones are great...u get 3 or 4 size hole sizes with one bit.I used to have three sizes.1/2,3/4, and 1in bits. If you've never seen one think of a top with a sharp edge ever 1/4 inch up,starting at the tip...I have drilled several hundred holes with some and less with others depending on the quality of the bit and wether or not I pushed it to hard or not.The vary in price from $30 to $80 and are very handy...Can be used like any bit in pretty much any type of wood,plastic or metal material..You can usualy find them at Home depot etc...But you may have to go to an elec. supply or plumbing supply to find a 1in...Only draw back,it can't be sharpend.Once you rurn(<-is that a word) it,toss it. I used to keep mine with my battery drill and used it more than any other bits I had.If any buy one and have never used one.U'll get the best life out of it you treat it like a cheep 1/8in bit...Moderate force and not quite full throttle on the drill..Don't supper heat it or the material,by drilling to fast or to long,especially on thick metal.

OLA!

Lil' Paul
Proud owner of TC21D
Laziness is the Father of invention.../w3tcompact/icons/laugh.gif

 

[Bird]

Lil' Paul, my brother loves that UNI bit, so he gave me one (1/2") and it's still in the package; never been used since I have regular drill bits up through 3/4". I guess I'll find a use for it someday maybe.

Bird