Irwin Blue Groove Augers

[Mr Ed]

I bought a set of 6 Irwin Blue Groove stub augers recently, not for fine woodworking but for boring holes through joists and the like. I've just started another bathroom at Sutton Towers and thought some new bits would make things quicker.

Turns out that they bite so quickly and aggressively that all but the smallest one stalls my 18V Metabo drill. Even with a mains drill they seem to bury themselves in the timber and nearly stall the motor.

Does anyone else have these and struggle with them?

I am considering grinding off the screw thread on the point to see if that reduces the bite a bit.

Ed

 

[Philly]

Ed
Yes, I have a set of similar bits - they are completely useless in a power drill. They feed in way too quickly and stall the drill. Be interested in your modification - worth a try!
Cheers
Philly

 

[Mr Ed]

I assume they're made for power drills though?

Ed

 

[Paul Chapman]

I reckon threaded bits in power drills are lethal - in my experience they rip the drill out of your hand :shock: Only ever used threaded spade bits in an ordinary mains power drill - I don't own a cordless one. Now I always file off the thread and make it a plain point and they work fine like that.

Cheers :wink:

Paul

 

[OPJ]

I used one of these Wood Beavers (they look very similar) on my workbench top last year and it was lethal yet awesome at the same time! I used a main-powered Metabo SDS drill held vertically in a Wolfcraft guide. But, even with both hands on the drill, it was racing to get away from me!!

I don't remember stalling the drill at all (the bench top was 70mm thick) and the cut as it broke through the underside was flawless - no breakout or splintering at all! Only trouble I had was that chips would sometimes clog around the end of the bit and had to be removed before I could start the next cut.

After drilling a large number of holes and then a chunky piece of chipboard, the bit is still as sharp as it was brand new!

 

[Paul Chapman]

Here are a couple of spade bits. The one on the right had a threaded point and I just filed off the thread. You just need to make sure you keep the point central

Seriously, I think the threaded bits sold for use in power drills should carry a warning. It would be quite easy to injure your wrist as the force of it tries to rip the drill from your hand. Maybe it's not so bad in cordless drills - don't own one and never used one.

Cheers :wink:

Paul

 

[Harbo]

Paul wrote

threaded bits in power drills are lethal

They certainly are - a few years ago I was drilling a hole through some floorboards with one - it took off, drilled through the joist and into a power cable!
Big bang, a melted bit and brown trousers!

Rod

 

[Paul Chapman]

:shock: :shock: :lol:

 

[WoodAddict]

I have to agree. Those drill bits and deadly! I used to use them for going through joists when I was wiring houses. Once they bite there's just no stopping them! :shock:

 

[Oryxdesign]

They need to be used on slow speed. They are great in an sds drill, hammer off, with a clutch, this aviods wrist snapping!

 

[ondablade]

Oh well.. I've just ordered a set specifically because they were advertised as being suitable for power use. Probably means the claim they can cut through a nail goes out the window too...

 

[Gary M]

They need to be used on slow speed. They are great in an sds drill, hammer off, with a clutch, this aviods wrist snapping!

Spot on :wink:

thesethings eat through joists but are more suited to impact drivers.

As with all self feeding bits,
Any more than 400rpm and they will break your wrists.

 

[Paul Chapman]

Any more than 400rpm and they will break your wrists.

Exactly - but it's pretty irresponsible of manufacturers not to say so. I wonder how many hapless DIYers have injured themselves with these bits?

Cheers :wink:

Paul

 

[Oryxdesign]

Any more than 400rpm and they will break your wrists.

Exactly - but it's pretty irresponsible of manufacturers not to say so. I wonder how many hapless DIYers have injured themselves with these bits?

Cheers :wink:

Paul

It does say they should be used on slow speed inside the pack

 

[woodbloke]

I am considering grinding off the screw thread on the point to see if that reduces the bite a bit.

Ed

I think that's standard procedure with sort of things... as Paul says, just turn the thread into a brad point - Rob

 

[chippy1970]

I got a set of them when they first came out and found them to be very rough. I thought I could use them for door locks etc but they just split thin hollow doors so I just use them for drilling rough stuff now.

 

[bugbear]

Any more than 400rpm and they will break your wrists.

Exactly - but it's pretty irresponsible of manufacturers not to say so. I wonder how many hapless DIYers have injured themselves with these bits?

Cheers :wink:

Paul

I suspect pro's are more in danger - more powerful drills, and less tendancy to read instructions...

BugBear

 

[Mr Ed]

Well to those who said they are fine on a slow speed, how right you are.

Just tried all sizes on the slower speed setting (which also has higher torque) and they work well. Isn't it ridiculous that we get so used to just pushing the drill trigger full on, that I for one didn't stop to think.

So problem solved!

Ed

 

[Gary M]

Just tried all sizes on the slower speed setting (which also has higher torque) and they work well.

Glad to hear they worked well for you :wink: Used properly they take the hard work out of drilling big holes.

I am considering grinding off the screw thread on the point to see if that reduces the bite a bit.

If you had of done that your augers would be scrap. The thread there for a reason. Im sure you will have noticed that they need a little push to get through the last bit, after the treaded part has broke through the other side. This is because the thread pulls them through, without it you would be trying to force the auger.

Think of a bit and brace (if you are old enough to remember what they are :lol: ) They need a thread at the tip of the bit to pull them through.

Grinding the thread off defeats the purpose , which is "self feeding".

If you want a bit without threads, just buy one without threads, simples :wink:

and less tendancy to read instructions...

[-X [-X :-$

 

[matthewwh]

Torque is the key!

The screw thread feeds the cutting edge with a constant thickness of shaving, if the bit is sharp and the drill has sufficient torque it will sail through beautifully. Lower speeds and more powerful drills give more torque and if the bit does snatch it all happens more slowly so you can let go of the trigger before it fetches your arm off. Most reputable manufacturers publish tables of optimum speed ranges for each size of bit.

A safer option for battery powered hand drills, is big brad point drills. These will cut holes over a foot deep.