De-burring the back of a blind through-hole

jcorsico · Mar 5, 2009

Hi -

Does anyone have any recommendations on how to debur the back of a blind through-hole? I often find myself having to drill blind through-holes in aluminum and then using blind rivets in these holes. It's often very hard, if not impossible, for me to debur the back of these holes, and the rivets seem to prefer for the holes to be deburred.

Does anyone have any recommendations? Maybe a small file with a tightly curved tip?

Thanks very much,
Jon

Spelunker · Mar 5, 2009

A blind thru hole??? Never heard of one.

beege · Mar 5, 2009

Is that like a hole half-way through tubing? where the breakthru area isn't easily accessible?

http://www.youtube.com/watch?v=sAZImFE_cpg

LatheWerks · Mar 5, 2009

sometimes I have to drill a pinhole through a tube of aluminum. I use a reamer to clean out the burrs on the insides of the tube, and a counterbore bit or center drill to chamfer the outsides of the hole

CS223 · Mar 5, 2009

http://www.ezburr.com/

surplusjohn · Mar 5, 2009

the mfg escapes me but another company makes clothespin style tools for small holes, these work very well and will deburr both sides in one pass.

Mud · Mar 5, 2009

surplusjohn said:
the mfg escapes me but another company makes clothespin style tools for small holes, these work very well and will deburr both sides in one pass.

Cogsdill?bbbbbbbbb

David Carlisi · Mar 5, 2009

For an inexpensive solution, try Mc Master Carr 4289A41.

http://www.mcmaster.com/#

jcorsico · Mar 5, 2009

Spelunker said:
A blind thru hole??? Never heard of one.

Sorry - should have been more specific - a through hole, but where you cannot access the back of the hole. For example, if you drill a hole in one wall of a peice of rectangular aluminum tubing - it is a through hole because it goes all the way through the one wall of the tubing; but it's also blind because you can't get to the back side of the hole, since it's in the middle of the tube.

Thanks again,
Jon

surplusjohn · Mar 5, 2009

yes, cogsdill, I had a mental block against that for some reason.

jcorsico · Mar 5, 2009

beege said:
Is that like a hole half-way through tubing? where the breakthru area isn't easily accessible?

http://www.youtube.com/watch?v=sAZImFE_cpg

Neat! This looks like it would solve my problem.

Spelunker · Mar 5, 2009

Ah, a much clearer picture now.

I am glad you found what you need.

Cheers :cheers:

Kevin

ben80 · Mar 5, 2009

deburr

CS223 said:
http://www.ezburr.com/

Our shop has used this type of tool for some time, they work great. We did not use them because of a blind hole , just did not want to turn the part over and do another operation on it and have the operater waist time and labor. They would deburr both sides one shot.
Ours were not quit like this but close.

If you want I will find out who makes them.

ben

stannp368 · Mar 6, 2009

Deburring back of hole

If the hole is near the end of the tubing, use a flat file to deburr. If the hole is not in proximity to the end of the tubing, use a reverse countersink if there is enough room to get it through the bottom & rotate by hand

gary350 · Mar 6, 2009

You can make your own debur tool for deburing a blind hole.

Lets assume you drilled several 3/8" holes in some square tubing and you need to debur the holes on the inside.

Turn a pieces of A2 steel in the lathe to about .435" diameter. Turn down the tip end a section about 1/4" long to .350" diameter. Leave a short section of the .435" about 3/4" long and turn the rest of the shaft down to .350" diameter. Both sides of the .435" diameter section needs to have a 45 degree angle so it can debur going into the hole and coming out of the hole. On the end with the .435" section mill a 3/16" slot down the middle of the rod about 4" past the .435" section. Leave about 2" on the end to chuck up in a low speed hand drill. Heat treat the A2 metal.

Put the tool in your drill. Insert it into the 3/8" hole. The fork end will close up and let the tool go into the hole. The end will spring open once it has passed all the way through the hole. Pull the trigger on the drill and pull the tool back until it touches the hole. You can feel it debur the hole. The RPMS of the drill turning the tool causes enough centrifugal force to keep the tool fork open. Once the job is finished pull the tool out and and your ready to debur another hole.

You have to make these tools specifically for each diameter hole you want to debur. The large dia. part of the tool needs to be about .060" larger than the hole your deburing. The shaft diameter is clearance. The milled slot only needs to be wide enough to allow the fork to close up and go through the hole.

RT_CINE · Mar 6, 2009

Don't know if you have ever tried it, but cryogenic deburring is good at getting burrs in deep holes that hand tools often cannot reach. If the burrs are light and not too big and thick, then the media should blast them off. Pricing is usually done by the lot.

We have had success with aluminum and stainless steel metals. Can't run many metals due to possible corrosion from cold temperatures and moisture.

Take a look here...

Cryogenic Deburring

smdubovsky · Mar 6, 2009

Noga makes reversible countersinks. Can do outside or inside holes. The blade flips open once inside. Pushing (and holding) the button flips the blade back to the narrow dimension parallel to the shaft to get it back out of the hole. Works really well and a super simple idea. Im sure I got mine from Enco or MSC.
http://www.noga.com/nogaProducts.php?catID=rvcn

Peter S · Mar 7, 2009

Just an ordinary Noga de-burring tool will get the underside of many holes (i.e. depending on diameter and depth of hole). Especially if you fit one of the slim tips. You simply work from the top side of the hole and hook it onto the underside and give it a couple of turns. An essential tool to have anyway I reckon, so useful on the lathe and many other places.

smdubovsky, thanks for tip on the reversible countersinks, thats a new one for me. I have been using noga and Varga for at least 25 years.

SKDiablo · Apr 7, 2009

jcorsico said:
Neat! This looks like it would solve my problem.

On that same note, manually:

http://www.youtube.com/watch?v=U6TIqlekuRU

www.jwdone.com

*In the interest of full disclosure, I AM associated with the company.

Dan DeBurr · Jul 14, 2009

Have you found a good solution yet? I work for E-Z Burr Tool and we have great success doing the back side of almost any hole .040 and up.
www.ezburr.com or send me an e-mail at: [email protected]

De-burring the back of a blind through-hole

Aluminum

Aluminum

Stainless

Cast Iron

Cast Iron

Diamond

Diamond

Stainless

Aluminum

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Aluminum

Aluminum

Hot Rolled

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Plastic

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Diamond

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