Back Yard Mechanic needs to Drill 7/8" Hole

[ampa]

I always thought those hole saws were strictly for wood, just by looking at the teeth on them. I never dreamed that you could drill holes in thick steel until i read this. I can't wait to try it out.

The holesaws for wood have no markings if I remember correctly, the ones for metal are normaly marked bimetal,I remember one time cutting a large hole in some 1/2" aluminium plate with a normal wood type holesaw, it took quite awhile,with my small tabletop drill press, it was toast when I finished,I didn't use no lube/oil just wanted to see what the difference was, now I all my holesaw sets are bimetal, you can still use these for wood as well>> Ampa

 

[DanD78]

I like to use bridge or car reamers. You can get them in 1/2" shank or morris taper. You need to drill a starter hole around 3/8 and let the reamer do the rest with a hand drill. Use lots of oil. I found all the ones I use on e-bay for next to nothing.

Dan

 

[andymil]

Don't try to use an intermediate bit such as 3/8" or 1/2".

What is the reason for not using an intermediate bit? I usually use a 1/2" or 5/8" after a 1/8" or 3/16" pilot hole when drilling 7/8"or 1" holes. I'm always willing to learn something new.

The windshield washer fluid works because the bits need a coolant, not a lubricant. If you don't clean up the fluid and maybe apply oil to the table, it might rust up on you. Even the column on my drill press will rust if I don't oil it occasionally.

 

[laurencen]

Seems to me step drills are close to these sizes, they will drill thro 3/8 plate, you may have to come from both sides of the plate and a 3/8 drill will easily do this

 

[jenkinsph]

Four pages on how to drill a small hole:laughing:

Come on SPRING 2010:thumbsup:

 

[SPIKER]

There are some relatively new types of hole saws out now that are more like a machine tool than a hole saw. they mount about the same way as old style hole saws on a col let and are becoming very popular in electrical shops for cutting holes in panels. They work great in just about anything though you need to make sure you clear the teeth when drilling deeper than the tooth is. (Tooth is about 3/8" high in bits above 1" and 1/4" in those below 1") they have much larger flat teeth that do not have a Kerf in them but the cutting edges from tooth to tooth changes from a point on the inner ring to a point on the outer ring area.

they come in 1/16 increments from 1/2" up. Costs are probably 20 bucks for Collete and 15+ for the bits. We use the heck out of them where I work, I've punched a 1-1/4" hole through 1" plate by drilling from both sides, it ends up looking like a machined surface cut... We use them in 18V Bat Drills

I wish I could remember the names of them I'm thinking Jacobs might have something to do with them.

http://www.grainger.com/Grainger/items/1FAH9?Pid=search
http://www.grainger.com/Grainger/items/1XRN8?Pid=search

What we use is sort of a combination of these two bits and works great


Mark M

 

[Renze]

I bought a torch last autumn and this makes the effort to salvage parts from wrecked machinery, a whole lot easier.

I cut some DOM tubes off an old silage feeding box, cut parts of it to length, torched holes in the plates and welded these DOM tubes in..
I only used the hole saw for positive markings to where i need to torch...

 

[Drexel]

I've used an arc welder with a small rod to burn out holes for a cat 1 pin. If you've got an arc welder that is. With a little file work the collar on the pin hides the imperfect hole. I've got a drill doctor that will sharpen bits up to 3/4" so I hate to spend money on a bit I'd have to take somewhere to have sharpened such as the 7/8 needed for the cat 1 pins.

 

[George2615]

As mentioned HF has the Silver & Demings drill set and step drills that drill up to 1 3/8". I have both and have not had any problem with either and the price was right.

 

[rdln]

Learn to sharpen your own bits on a bench grinder, its not hard.