Hex shank drill bits vs regular drill bits.

[atownmack]

Are hex shank drill bits less prone to slippage than regular drill bits when using a drill?

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[Ainsley]

Do you mean 1/4" quick hex or just flats on the shank?
I stick with flats on the shank like the Walters SST, champion brute platinum, and cle-line stuff.
My pet peeve is when a round shank slips in the chick and makes a burr so it no longer slips into the index nicely. Obviously you can just flip the bit around but then they aren't uniform.

 

[383 240z]

I'm not a fan of the drills with flats. They always have more runout than a regular round drill. However for people not measuring holes to .001, I doubt you will notice the difference Ainsley keep a fine stone, or diamond hone around. You can dress the burrs off and keep your drills running true.

 

[oldldh]

I like mine...

No more slipping...

So far, they're a better bet, for the work I do, than the round bits...

 

[Milton Shaw]

Make sure your drill has a clutch on it. I had a 7/8 horsepower 1/2 drill that I used a drill extension with flats on it. When it hit a nail drilling through the floor, I could not hold the drill and it twisted up pretty good. I have since cut the hex portion off and use it with a round shank and let it slip if it needs too.

 

[dewalt378g]

Not all hex shank bits are created equal. Those with the pewter colored shanks are made with some kind of pot metal. That metal is soft enough to break or slip on the bit that is molded within. Get one piece shanks if you can or the three facet shanks like the Milwaukee ones pictured.

 

[hautpot]

If your twist drills are slipping your chuck is a *************

 

[All]

My limited experience with drill bits embedded into 1/4" hex shanks has been woeful inaccuracy of the drill, due to precession, where the tip of the drill wobbles like a spinning top does when losing it's spin.

It could simply have been the quality and trueness of manufacture in the hex shanked drill bits I happened to try, but after two go arounds (pun intended) with them, I swore them off and use regular drill bits instead. There is just too much risk of variance in the manner in which the drill body is pressed into the hex shank body. And this is almost universally the case when the desired drilled hole diameter is less than the distance across two apexes of the hexagonal 1/4" shank, which is greater than 1/4".

On larger diameter bits of a continuum of a common material machined down to three flats to lock into 1/2" chuck jaws, I have not had a problem with precession. Nor have I had an issue with medium diameter bits machined down cylindrically to fit 3/8" chucks.

But the hex shank deals are a no go for me. Unless someone can post a specific part number (not just brand, because even the best brands of yesteryear have cheaped out now days) that is known good and true, I'd stick with regular drills for accuracy.

 

[larry_g]

As a homeowner hanging a picture frame hex works . As a machinist hex is not the correct tool. You have to decide where between the two examples you belong and the work your doing. Each has its place, and I have both.

lg
no neat sig line

 

[Outlawmws]

As a homeowner hanging a picture frame hex works . As a machinist hex is not the correct tool. You have to decide where between the two examples you belong and the work your doing. Each has its place, and I have both.

lg
no neat sig line

 

[Ign]

As a homeowner hanging a picture frame hex works . As a machinist hex is not the correct tool. You have to decide where between the two examples you belong and the work your doing. Each has its place, and I have both.

lg
no neat sig line

This. Trying to load a flatted or a hex shank in a mill 3 jaw chuck is a PITA. Round only for me.

 

[All]

as a homeowner hanging a picture frame hex works . Each has its place, and i have both.

-1. As a homeowner, I've hung picture frames light enough where they could be placed exactly where they were artistically desired, not where the studs are. For these light objects, drywall inserts are used, and in order for the plastic drywall insert to get a good bite, a certain hole size is specified. If using a hex based bit that wobbles with precession, the hole will be larger than specified, and the plastic drywall insert will no longer friction fit in the hole. A larger insert then must be located, or a one of a different design (such as an auger) or yet another hole in the drywall must be drilled (and patched later when the house is for sale), losing the original location of choice (30 minutes more of spousal deliberations) to hang the frame.

IMHO, there is no place for a wobbly drill bit, except back on the boat where they came from, in the form of recycled metal.

 

[Outlawmws]

Your first problem is ever using those plastic expanding wall anchors in sheet rock. They are **** for that use, and one use of a screw in and out and the sheet rock will be expanded and the so-called anchor will be loose anyway....

Almost any picture can be hung with a pair of appropriately sized picture hanging hooks and hold up fine. You also don't have the problem of pictures not staying level with a two hook hang.

If you are hanging something really heavy you need to be in studs, or else hang a hanging bar across studs, then hang the picture/mirror on that...

If you really need a screw in a wall and can't hit a stud, get those metal screw in anchors; self drilling, anchor securely, and will take having the screw run in and out many times without issue. I've even re-threaded them for a different thread as needed.

Larrys' point is still valid. Use the hex shank drills where absolute precision is not crucial, and round shank bits where it is... He simply used picture hanging as an example...

 

[Outlawmws]

Edit; Dang it I should have checked before replying to a repeat quote spammer, but the answer is still applicable:

They always have more runout than a regular round drill.(spam image deleted...)

And they are not intended to be used in either a DP or a mill...

Just how much effective runout do you think a hand held drill has?

 

[Elginz]

They each have there place just not the same place, I have all three kinds in some sizes.

 

[atownmack]

I don't have a drill that slips, just wanted to know. Logically it seems that the Chuck would hold a hex better than a round bit, but I guess each has its own place.

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[uart]

I don't have a drill that slips, just wanted to know.

Yes, obviously a hex shank drill will require less clamping pressure in a chuck to stop it slipping. People are just pointing out that, apart from slipping, there may be other draw backs to them.

Also be aware that you don't need to go for a full hex shank to get the "non slip" advantage. A tri-flat shank is the most common method of providing improved resistance to slippage. Some people prefer this style for bits that they'll use predominately on a hand drill.

While a good quality chuck should hold a regular round drill bit without problem, the tri-flat design can be particularly useful for bits that have a significantly larger diameter head compared to the shank diameter. I find them useful on step bits and countersinks.

Tri-flat shanks are usually (but not always) just machined into the existing shank, without necessarily reducing it to a standard size (like 1/4" for example). Hex shanks drills on the other hand are usually (but not always) made to a standard size (typically 1/4").

A tri-flat machined onto an existing shank is generally going to be a lot more accurate (with regard to run out) than cheap drill bit pressed into a hex piece of pot metal.

The attachment shows the difference between typical tri-flat and hex shanks.