# Drill flute styles



## natewi (Oct 16, 2019)

Hello again,

Firstly I'd like to say thanks for all of your previous help. This forum has been a game changer for me, much appreciated.

I recently upgraded to a 3/4hp floor drill press from a very small counter press. I mainly drill mild steel, and have run into an issue when drilling through holes in hand forged drawer handles.

The new press works great for blind holes, but when drilling through holes in roughly 1/4-3/8" thick material, right when it breaks through the other side it snags and rips the vice out of my control and up onto the bit. Before this wasn't an issue because the smaller press would slip before it would do this, and I'd just baby it through. 

My first thought is that i need to get bits that have a less drastic spiral angle (not tip angle but the whole flute). I've looked on MSC industrial and can't seem to find an option for changing this angle... 

My next thought is that due to the material being hand forged and uneven, it is snagging when it breaks through. 

Last thought is that the press itself is wobbling ever so slightly causing the bit to snag.

What do ya'll think?

Thanks again in advance!!


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## natewi (Oct 16, 2019)

natewi said:


> Hello again,
> 
> Firstly I'd like to say thanks for all of your previous help. This forum has been a game changer for me, much appreciated.
> 
> ...


Also forgot to mention, would a parabolic flute solve the problem? Currently using spiral.


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## extropic (Oct 16, 2019)

What diameter drill are you talking about?


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## natewi (Oct 16, 2019)

extropic said:


> What diameter drill are you talking about?


ranging from 5/32 to 7/32


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## T Bredehoft (Oct 16, 2019)

Is the part securely clamped in a secured vise?


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## benmychree (Oct 16, 2019)

The usual technique is to ease up on feed pressure as the drill is starting to come through.  On a heavy drill press, it is wise to fasten the vise down to the table to avoid having it wrenched from your hand.  I usually use a ViseGrip welding clamp (the one with the big U shaped jaws) to hold the vise on my drill press in such circumstances.


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## natewi (Oct 16, 2019)

T Bredehoft said:


> Is the part securely clamped in a secured vise?


It is clamped in a vice, however due to the nature of hand forged items and being efficient, i can't practically clamp the vice to the press table.


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## matthewsx (Oct 16, 2019)

This is where your new found tool appreciation comes in. If you'll be doing this job frequently look into building some kind of jig that makes it fast and easy to drill these handles. It can be made from wood and secured directly to the table rather than using a vise.

As always, pictures....

John


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## Tim9 (Oct 16, 2019)




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## Tim9 (Oct 16, 2019)

Had trouble adding this text. Anyway, I had same problem you are describing. I put one bolt on just one corner of my vise and used a t-nut which slides in the slot. I steady vise with one hand while drilling. By using just one bolt.... it’s quick since I don’t have to tighten the vise down and I can swing vise back and forth to line the bit to the hole needed on work. Also...little bit of loctite on the T-nut keeps vibration from loosening bolt.
   Also.... I use a small machinist vise quite often. Just clamp it in the bigger pictured vise above.


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## extropic (Oct 16, 2019)

natewi said:


> ranging from 5/32 to 7/32



Those are small enough diameters that you should be able to handle.
I suspect that major factors are less-than-sharp drill bits so you're advancing them with too much pressure.
Too much pressure results in the break-through happening with too much metal left to cut. In other words, as soon as the web breaks through, the cutting edges spiral through.

To test my theory, get some new, top quality bits, use a good lubricant (I like dark cutting oil as used in pipe threading), and let the bit cut. Don't 'push' the bit through. As was previously mentioned, it's key for you to develop a 'feel' and reduce your feed pressure as the web breaks through.

Obviously, it's good advice to rigidly secure your vise/work-piece but I understand the practicality of what you're trying to do. How about this? Bolt your DP vise to a base plate that extends beyond the back of the vise far enough to bear against the DP column (anti-torque). Additionally, tighten a collar around the column with just enough clearance to let the base plate slide between the table top and the collar (anti-lift). Many ways to skin that cat.


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## matthewsx (Oct 16, 2019)

Another tip is getting a foot-switch for your drillpress. 



			Amazon.com
		


I've had one for years and it makes holding stuff while drilling much easier, also you can stop the drill in an instant without letting go of your work.

Also get a heavier vise 




Stuff catching while you're drilling is just something that you learn how to avoid more than changing bit styles IMHO. It only takes a couple of times getting your fingers whacked to decide to put some effort into making sure it doesn't happen. 

John


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## RJSakowski (Oct 16, 2019)

Parabolic drills are used for better chip extraction in deep holes.  

I caqn appreciate the part to part variation of a hand forged piece can make it difficult to securely clamp.  If I were drilling a multitude of holes, I would invest the effort in making a hold down clamp.  Toggle clamps can be quickly and easily operated.  A piece of flat stock with an appropriate hole on one end and the other end fastened to a backing plate which is clamped to the table will hold the part and the toggle clamp  to hold the flat stock.  
To use, insert the part and start the hole, then activate the toggle clamp and finish the hole.  

McMaster Carr is a good source for the clamps and clamping forces of over a ton can be achieved.


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## extropic (Oct 16, 2019)

Is the bottom of the work-piece essentially flat and perpendicular to the DP spindle? If the drill bit doesn't break through a normal surface it can be a significant factor.


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## natewi (Oct 16, 2019)

Tim9 said:


> Had trouble adding this text. Anyway, I had same problem you are describing. I put one bolt on just one corner of my vise and used a t-nut which slides in the slot. I steady vise with one hand while drilling. By using just one bolt.... it’s quick since I don’t have to tighten the vise down and I can swing vise back and forth to line the bit to the hole needed on work. Also...little bit of loctite on the T-nut keeps vibration from loosening bolt.
> Also.... I use a small machinist vise quite often. Just clamp it in the bigger pictured vise above.


Great idea. Thanks!!


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## natewi (Oct 16, 2019)

extropic said:


> Is the bottom of the work-piece essentially flat and perpendicular to the DP spindle? If the drill bit doesn't break through a normal surface it can be a significant factor.


No it's curved, I think you nailed it. Since it's not flat when it breaks through it snags on the thicker side.


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## Illinoyance (Oct 16, 2019)

Learn to recognize when the drill is about to break through then reduce your feed.  A drill press is a very basic tool.  In spite of that some finesse on the part of the operator is needed.


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## homebrewed (Oct 21, 2019)

Work trying to climb up your drill bit is commonly encountered when you're drilling some plastics and brass, or anything else that tends to grab as the bit breaks through the other side of the hole.  This can be addressed by "dubbing" your drill bits to reduce the rake of the cutting flutes.  I did this to dedicate bits for drilling brass, using a 600-grit diamond stone.  Run the stone across the flutes, keeping it parallel to the axis of the bit.  It only took a few passes to change a nasty drilling job into a no-excitement procedure.


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