What metal drill bit for putting a Piranha on?

[BXpanded]

Whether it's .790" or .890" that's one thick bucket side! Most are about .125" to .1875" Usually takes about 5 minutes to drill that.

 

[Scooby074]

Whether it's .790" or .890" that's one thick bucket side! Most are about .125" to .1875" Usually takes about 5 minutes to drill that.

I dont think thats the side of the bucket. I think its the cutting edge.

 

[RoyJackson]

i looked it still looks like .790 to me few thousandths from .800

Take a look at the scale...not the dial. Note the movable jaw is well past .800 and the .900 line shows (but the numeral "9" does not). Being well past the .800 mark indicates the measurement is well past .800.
I work in Quality Assurance for a living, BTW.

 

[RoyJackson]

My tractor dealer uses a magnetic drill press to drill holes like what you need- in seconds! It's pretty impressive.
Try a local machine shop.

They are nice...but can be a real PITA is you need to locate them at a specific location on the workpiece. They're mighty heavy too!

 

[RoyJackson]

Yeah, that caliper dial is slightly out of sync with the caliper scale. If the thickness were really .890, the scale would be crowding .9.

It is crowding .900...read post #23.

 

[chim]

They are nice...but can be a real PITA is you need to locate them at a specific location on the workpiece. They're mighty heavy too!

When the guys in our weld shop want to use a mag drill in an odd place, I've seen them temporarily clamp or weld a plate where they want the drill to stick.

I drilled for a wear edge with a 1/4" DeWalt 18V impact driver. They make "impact ready" drill bits up to at least 1/2", which is what I used. They also offer a limited range of hole saws. The really nice feature of using the impact driver is that it doesn't twist your wrist. You can use any compatible drill bit or hole saw with one hand in positions that would be hazardous to your ligaments with a torquey corded VSR.

 

[Baby Grand]

It is crowding .900...read post #23.

Take a second look at that dial caliper's scale.
If I count hash marks, I get .795. (edit .805 - .815 based only on hash marks)
Would be interesting to see it zeroed out, though.

 

[RoyJackson]

Take a second look at that dial caliper's scale.
If I count hash marks, I get .795.
Would be interesting to see it zeroed out, though.

Well, not much use going back and forth on this...if you use calipers professionally, I think you'll change your mind. If you don't use them, well, as I wrote, not much use going back and forth...

However...looking at the caliper, visualize where the movable jaw would be (relative to the .100 mark) if the measurement was .095"...that might help

 

[radioman]

Hmm, how often did you try to resharpen your drill bit when drilling the monster lip? hopefully you are using a drill with low drill speed. I notice if I try to drill something and its not "cutting" , I stop and do a touchup on the bench grinder. When you are drilling, keep the hole pooled and filled with oil so its always in a oil bath. Even a cheap bit will cut and give you spirals waste, although it might be for a second. I always been drilling metal this way, even if it a PIB to sharpen,sharpen,sharpen bit for one hole. Now I have cobolts,hss,silver and deming bits - so this way I would have several bits at once to drill a hole and when they get dull, I can just swap em out till none left and make one trip to grinder.

 

[murphy1244]

I see .893

 

[tomfifield]

You could rent a mag drill, I say this after seeing the broken hand!
As far as the calipers reading goes take a close look, at the hash marks, you can see it is just over .8. look at the calipers you see the numbers start at 0 and the numbers indicate the the line above them. The dial is off so don't even take it's reading into affect. I have worked with this kind of tool for 35 years at Boeing making parts for the big jets.

 

[Baby Grand]

Count hash marks, starting with the zero hash mark ...
Anyone who has worked a lot with mics and vernier calipers will understand a resistance to accepting anything a dial indicator reads without double checking it.

 

[RoyJackson]

Count hash marks, starting with the zero hash mark ...
Anyone who has worked a lot with mics and vernier calipers will understand a resistance to accepting anything a dial indicator reads without double checking it.

I have worked with mics, vernier calipers (height gauges too, BTW) and have done metrology for many many years...no "resistance" as you wrote, but it's .890 plus a few thousandths.
Again, visualize where the movable jaw would be if you had a .095" gage block stack...pretty closely aligned with the .100 mark...you may or may not see the .1 numeral.

I don't care for dial calipers....much prefer the digital type. The gear drive or "string" drive (on the cheaper calipers) tend to jump a tooth or break the string, rendering the caliper useless unless you want to tear it down and rebuild it. The gear drives are a pain...the string drives are a major pain...

 

[oosik]

RoyJackson,
The dial caliper reads 0.895. Digital is so much easier - After hours & hours of reading dial calipers I have found errors can creep in. Digital is right there for you - unless you have fallen asleep.

 

[RoyJackson]

RoyJackson,
The dial caliper reads 0.895. Digital is so much easier - After hours & hours of reading dial calipers I have found errors can creep in. Digital is right there for you - unless you have fallen asleep.

Yeah, but dial calipers were a major improvement over the older vernier scales...with the caveats I listed in post #33.
Dial and digital calipers weren't around when I first got into QA/QC (yes, I'm a dinosaur). All calipers require the operator to develop a "feel", but with vernier calipers, one also had to determine the best alignment of the marks on the scales. A 5x or 10x loupe was frequently required.

Digital calipers are great (my favorite are the Mitutoyos), but you still need to develop the "feel".

 

[tomfifield]

Look some more at the calipers. Count the spaces and you will see the numbers indicate the line above them. When they are closed it is at 0. The number 1 is in the first space so it has to open to the line above the number 1
to be at .1.
I can not understand how you can not see what it reads, it is just a bit over.8. As you can see the last number you see is .8, then the caliper is open to just over the .8 mark. This makes it about .81 or less.
The dial has nothing to do with any thing as it is not zeroed. Count the spaces and you will see the what the numbers indicate.

 

[Leejohn]

My god what are a few .001 when drilling something like he is doing.

 

[tomfifield]

Not much, and he will be going through a hrd spot. The informationm that I presented was simply to clear up how to read a caliper.

 

[bnhawkins]

The .100 thou vertical mark is to the right of the 1 so the .800 thou vertical mark must be to the right of the 8 - calipers are reading .795

 

[tomfifield]

Look close it is to the right of the hash mark, you can clearly see the hash mark above the 8, click on the photo and enlarge it.