Irwin speedbore drill bits

[john lucas]

I've tried several different drills for hollowing out the center of hollow vessels and I usually either use a 3/8" bit when I need to go deep or a chinese forestner style bit with extension for shorter larger holes. Neither one works very well.
Yesterday I was at Lowes and saw the Irwin Speedbore bits. I bought the 3 flute variety pack of 3 for $12.95 and a 12" extension for $9. I tried them out this morning and they work great. You can use a hand drill but you have to push a little on endgrain. In a chuck in the tailstock it works great. The threads on the leadscrew don't pull it in, on endgrain so it was perfectly safe to use in the tailstock.
They have a forestner style cutter that is heavier duty and takes thier 7/16 extension. I want to try one of those but it looks like it will run about $50 for the pair when you add on our states super high tax.

 

[DeanGThomas]

I'm wondering if you can shorten the point in the middle so that you could drill more like a forstner bit. What do you think, John?

 

[Joe Greiner]

John, I bought this set at my local Lowe's within about 1/2 hour of reading your post, and here are my findings.

Overall, this is a valuable addition to my arsenal. The set of 3 bits includes 5/8-in, 3/4-in, and 1-in. I tried each bit in end grain on a scrap block of Southern Yellow Pine, using a hand-held cordless drill (Craftsman 225 in-lb torque). Each bit advanced nicely, with little grabbing, at least after filling the screw threads with dust. The 1-in was a little grabby at first, but advanced well enough afterwards. (This was, after all, in a low-power hand-held drill.) I tried them again in the other end of the block, this time in my drill press. Their performance was equally as good, if not better.

I next tried them in end grain on a hickory log in my stash, again with the hand-held drill. I wasn't surprised to find more difficult advancement, and the 1-in size in fact stalled the drill, because I wasn't able to fill the screw threads with dust. I tried a new Forstner 1-in bit in the hickory for comparison; it didn't suffer the stalling of the Irwin, but didn't advance much either (still hand-held, remember).

I didn't try them in my lathe, but I expect their performance will be substantially the same as in the drill press.

The finish of the hole boundary is superb, maybe even better than Forstner bits. The 3-flute bits are a vast improvement over the 1-flute terror I'd been using to drill vase ends for inserts. And spade bits in end grain are, to me, non-starters which leave very ragged surfaces in end grain.

I believe I covered the range of soft- and hard-woods I'm using. I'd suggest pre-boring in a piece of scrap to fill the screw threads with dust, so as to reduce any tendency of grabbing on the workpiece itself, especially for a hardwood workpiece. The filled threads are then substantially equivalent to grinding off the threads. [Take note of this, Dean, if it helps to address your concern.]

If forced to make a complaint, it would reside in the packaging. I cut off both ends of the blister pack for each size, to provide a storage pack. My only serious complaint with the packaging is the oversize hump at the front, which needlessly consumes scarce volume in my tool drawer.

I'm quite impressed with these tools. Thank you for your heads up.

Joe

 

[Steve Worcester]

I have been using them for some time now. I use them i the tailstock and at first I had a heck of a time with them grabbing to point of pulling the drill chuck out. I finally ground off the screw point. It doesn't advance as fast nor as straight, but it works fine. I mostly use them to clear out the center until I can get a hollow tool in there.

 

[john lucas]

Steve I didn't have any problems so far with it pulling the chuck out of tailstock but I could see how that might happen. I use them the same as you to just get rid of the center waste area so I can start with the bowl gouge.
I think grinding the threads off the point would be easy and solve any pullout problems.

 

[MichaelMouse]

If you don't need the auger to feed the bit, just use a brad point. I've got a cheapo Chinese set that I've used for a few years, though the steel is so lousy I use an old chainsaw file to touch it up prior to use. Clears shavings well with thoise big flutes like these auger types.

If you want a self-feeding bit, get a ship auger, available in great lengths and rotate the head by hand.

 

[john lucas]

I have some of the chinese brad points. The Irwin bit cuts many times cleaner and faster. I prefer them to be non feeding because I use them mostly on the lathe and want to control the depth. I will probably grind the point down with no threads and short enough to just clear the edge cutters.

 

[Mark Mandell]

I have some of the chinese brad points. The Irwin bit cuts many times cleaner and faster. I prefer them to be non feeding because I use them mostly on the lathe and want to control the depth. I will probably grind the point down with no threads and short enough to just clear the edge cutters.

John,

If you grind those feed threads, you should carefully leave the point precisely centered (like a brad-point) so your bit will run more accurately. That center point should always be dead center of the mass and preceed the wing cutter points into the wood. Also be carefull about the wing points and grind them to be exactly the same length from the flutes. One longer or shorter will make your bit cut off-center. I've had Irwin spade bits with uneven outside wing points right out of the blister-pak that would bore as straight as other kinds of bits once I reground the points to be even.

 

[Joe Greiner]

If you first drill into some scrap, endgrain, the screw threads will fill with dust, and then it'll behave the same as if you ground off the threads, without introducing any eccentricity. Try it this way.

Joe