Hole Saw - Won't saw all the way through

[Pooh_Bear]

I went today and bought a bi metal hole saw.
http://www.lowes.com/lowes/lkn?action=productDetail&productId=178327-28303-34016-16A&lpage=none

I chucked it up in the drill press and started drilling in 3/8 plate.
Pilot bit drilled real good. Saw had some trouble getting started,
but after it did it drilled good, for about 1/4 inch deep.

I have drenched it in cutting oil. I have cleaned all the chips away from it.
I have tried light pressure and moderate pressure and heavy pressure.
But it won't go deeper than 1/4 inch.

What am I doing wrong.

I have 5 holes started. Plan on doing the other 3 tomorrow.
Then I'm just gonna flip the plate over and drill from the other side.
If it works then that will finish all the holes in that plate.

Then just 10 more holes to go.

Pooh Bear

 

[MrJimi]

I use this kind and I never have any problems
http://www.use-enco.com/CGI/INSRIT?PMAKA=301-0205&PMPXNO=947966&PARTPG=INLMK32

for $10.95 ya cant beat the set
Jim

 

[rswyan]

What am I doing wrong.

Adjust the height of your drill press table (up) - or the depth stop .... you're out of spindle/quill travel.

And make sure that after you do drill the first one all the way thru you remove the cut plug from the hole saw otherwise you will have trouble later once you get enough of them in there.

 

[wushaw]

Adjust the height of your drill press table (up) - or the depth stop .... you're out of spindle/quill travel.

And make sure that after you do drill the first one all the way thru you remove the cut plug from the hole saw otherwise you will have trouble later once you get enough of them in there.

I was going to say the same thing...I have had it happen to me where the adjustment nut works its way down a little and no matter how much pressure you input it just won't cut anymore

 

[Pooh_Bear]

I should have 4 inches of quill travel.
And the pilot bit is 1/2 inch above the plate.
Don't think the problem is not enough quill travel.

Hope the slugs aren't hard to get out once I do get a complete hole.

If I have to turn the plate over and finish the hole from the other side
I believe it will still be faster than using the twist drills.

Pooh Bear

 

[rswyan]

and no matter how much pressure you input it just won't cut anymore

Same here - more times than I would care to admit.

 

[rswyan]

Well 4 inches is pretty good if that's what you actually have .... I only have 3 1/8" on my 17" Craftsman drill press .... and I think it had the largest travel of most of the ones I looked at, at the time (and was the reason why I bought it over the others)

You're using the same hole saws I have here - Lennox. I've hogged out a 2" hole in 1/2" plate several times and numerous 1" and smaller holes with mine.

What speed are you running these at ?

The other thing I have noticed is that sometimes the cutting action will just stop for awhile - I continue to apply alot of pressure and eventually the saw will start cutting again.

 

[GuglioLS]

Perhaps the hole saw is not exactly straight or the metal is expanding and binding against the inside of the hole saw:

 

[Pooh_Bear]

My lowest speed is 240 RPM.

MrJimi, I have a Silver and Deming drill bit set from Harbor Freight.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=527
I will be using it for a couple of 3/4 and 7/8 holes I have to drill.
I drilled one 1 inch hole with it and it did ok. The hole saw is smoother.

Pooh Bear

 

[3RRL]

Pooh Bear,
a) If you still have travel on the quill and b) If you don't have anything plugged inside that hole saw, then I think you work hardened that steel piece. Now you'll have to use carbide or a plasma torch to cut it or try flipping it over.