Drilling 16mm metal plate...
Drilling 16mm metal plate...
(OP)
Hi,
What do you use to drill 16mm metal plates? Normal drill may not work..
What is your comment on the technique of using acetylene torch to put a hole in the metal plates? But it doesn't exactly put a 16mm hole.. but bigger.. so if you use a washer and nut. would it no longer be an effective anchor because of the washer?
The metal plates will not be used for column but for supporting a rafter gable middle (image 2 wide flange welded together and supported by the metal plates)
What do you use to drill 16mm metal plates? Normal drill may not work..
What is your comment on the technique of using acetylene torch to put a hole in the metal plates? But it doesn't exactly put a 16mm hole.. but bigger.. so if you use a washer and nut. would it no longer be an effective anchor because of the washer?
The metal plates will not be used for column but for supporting a rafter gable middle (image 2 wide flange welded together and supported by the metal plates)






RE: Drilling 16mm metal plate...
For field drilling, an industrial rated, 3/4" chuck, geared-down, reversible, single-speed electric drill. One of these will knock you on butt if the bit jams during drilling - plenty of torque.
Here are the specs for this brand:
https://www.milwaukeetool.com/power-tools/corded/1...
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Drilling 16mm metal plate...
That makes a BIG difference in what tool is best.
How accurate is the hole to be located, and to be drilled?
How many holes in a single 16 mm plate?
Is the material magnetic, or an AL or stainless (non-mag) alloy?
What orientation in the plate, is the drill, and the hole?
Are there ANY interferences or restrictions above the plate that might get in the way of the drill?
Are you going to be doing a "one of" or many, or need to go to a whole bunch of different "field" locations?
(Hint: No "good drill" are cheap.
RE: Drilling 16mm metal plate...
DO NOT USE A TORCH for this! First, you don't need to. Second, the hole will have to be reamed to get a smooth surface. Third, you don't want that much "slop" in the hole size relative to the bolt size, even if you use a washer.
A good, sharp drill bit will go right through the 16mm plate, assuming it is mild steel.
RE: Drilling 16mm metal plate...
If you use a normal electric drill (SDS) with 16mm drill bit.. can you cut thru the 16mm thick plate (so as not to be confused.. both the thickness of metal plates and hole is 16mm)??
The metal plate is half meter by half meter long.. there will be about 6 holes and only 8 pcs of it.
RE: Drilling 16mm metal plate...
Maybe, maybe not, it depends on the drill and, as Ron stated, the quality of the bit. Try it and see... don't press down too hard, let the drill & bit do the work.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Drilling 16mm metal plate...
RE: Drilling 16mm metal plate...
There are magnetic base drill presses for doing this job.
http://www1.milwaukeetool.com/tools/magnetic-drill...
You might also plan on drilling a pilot hole and then stepping up in size. This can cut the torque required by limiting the amount of material being sheared - but it works best with a magnetic base drill press.
I suspect there are also portable punches.
http://www.roperwhitney.com/portable-heavy-duty.ht...
http://www.nittokohki.com/tools/products/machineto...
RE: Drilling 16mm metal plate...
The metal plates have not yet been connected. I don't have budget to buy thousands of dollars of drilling equipment just for those few metal plates that I'd not do again.
I plan to just go to machine shop. Hope they have the technology to drill such thick plates. Most of their experience are just with 5mm and less thick plates.
Is 16mm base plate common? How thick do you use yours and how do you put hole in it? using your own machine or borrow from others?
RE: Drilling 16mm metal plate...
"You might also plan on drilling a pilot hole and then stepping up in size. This can cut the torque required by limiting the amount of material being sheared - but it works best with a magnetic base drill press."
RE: Drilling 16mm metal plate...
I see no reason to drill these holes in the field since you are using post-installed anchors. Given that, the holes could be drilled on a drill press...a simple task...again, with proper and sharp drill bits.
RE: Drilling 16mm metal plate...
Keep in mind it is common that post installed anchors will be moved in the field due to rebar and other constraints. If you allow them to core the holes they can go thru the rebar, but a hammer drill does not. You might want to drill the bolts first if you are not going to allow them to use the torch in the field. A 4 - 6mm design gap is not uncommon for a base plate just as Ron suggests.
RE: Drilling 16mm metal plate...
RE: Drilling 16mm metal plate...
Ill bring the 16mm thick plates to the machine shop tomorrow to see if they have the equipment to drill it.
Now id like to ask if you guys put structural epoxy underneath base plate. wont it make the base plate even stronger as it is binded to the concrete on a molecular level?
also in rafter support, the forces acting on the bolts are not uplift but sidewAy shear.. right? in typical bolt you buy in stores that are not branded Hilti, how good are the strength usually?
RE: Drilling 16mm metal plate...
The holes are not large and the material is not especially thick. Your description was that you'd made it to the field without the holes.
RE: Drilling 16mm metal plate...
Structural epoxy will not increase the capacity of the baseplate. It is also not workable as a baseplate "grout" without adding oven dried sand as a filler. Stick with non-shrink grout.
If you are a structural engineer, you need to get serious about not compromising everything for the sake of cost and expedience. I know that sounds harsh and you might be in a country with fewer resources; however, you must push for the safety of the structure and protection of the health, safety and welfare of the public. Your responsibility is greater than that of the contractor or the owner.
RE: Drilling 16mm metal plate...
Actually there are already 4 existing 16mm J-bolts of length 7" imbedded inside the corner bars inside stirrups. The middle add-on additional anchor bolts are for increase safety margin because the designer doesn't know the exact condition of the existing bolts.
For the bolts already in the column top. How am I supposed to aligned the blank metal plates to the holes and let the machine shop drill it? I plan to use Styrofoam to create the hole impression and use this over the bare plates and marking with marking brush. How do you do it?
Another thing. The contractor original plan is to use acytelene torch to make hole on the base plates.. and since the holes can be bigger than the existing bolts.. the contractor would then weld the bolts right to the metal plates holes.. what do you think of this approach?? What would be wrong with it?
The original designer said he will think about all this. He has never experienced it himself so may also ask others. We'll discuss and collaborate what we learnt. Thanks.
RE: Drilling 16mm metal plate...
It is not clear whether you're talking about bolts or all thread anchors. Either way, when the contractor mentions welding to either, this should raise a giant red flag.
I think there are, apart from those holes, other issues at your construction site that need professional attention.
RE: Drilling 16mm metal plate...
That's why I am reviewing the contractor plans. I know welding the threaded bolts to the metal plate is not allowable.. but what is the reason? Is it because the welding only bind the upper part of the metal plates and there is not enough locking force for it? What else.. I need to write a report to the architect and engineers. Thanks.
RE: Drilling 16mm metal plate...
Some grades of anchor bolts are quenched & tempered making them brittle. If welded they can crack under cyclic loads.
BTW - would you like to borrow my drill?
RE: Drilling 16mm metal plate...