Dull dril bits

Floats

Floats

Well-known member
Hi Gents,
Please correct me if I am mistaken.

I think I have found the best, the most cost effective and quickest means to dull drill bits in seconds. This is off course if you prefer/want or like dull drill bits.

I removed the old linings from the brake shoes off my Model A and I found that the brass or is it bronze rivets dulls the bits in seconds.

Have anyone had this experiance or am I using poor quality bits?

Regards
Chris
 
X2 what Mike said !
Brass is soft metal rivet, so that it will not cause wear problem for drum if contact is eventually made. Even a dull bit should cut a brass rivet...somewhat. And, using a wood bit that seemed sharp to cut metal..even soft metal is a bad idea.
 
Never came across that problem. I have found that a dull bit will catch soft materials and rip rather then cut it. This will leave what look like a coating on the tip of the bit.
 
My friend bought some drill bits that came from China. He went to drill a hole in a piece of wood and the drill bit twisted. He gave the set to his brother. :D
 
Maybe the brass has work hardened? That happens to brass i try to drill.
Tom Wesenberg said:
My friend bought some drill bits that came from China. He went to drill a hole in a piece of wood and the drill bit twisted. He gave the set to his brother. :D
Click to expand...
That happened to mine too.
 
sounds like wood bits. My dad has a set and as soon as he drills anything other than wood they dull. Not sure why he keeps them. They are even marked on the case wood bits.
 
Most suppliers carry a brake riveting tool. It has a punch to remove the old rivets, and rivet setting tools to add the new rivets. Works well for me.
 
Sounds like this type of bit...
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msh,

have been wondering why I have worked so hard for years and got nowhere..........
I've been using that exact drill!
 
ronn said:
msh,

have been wondering why I have worked so hard for years and got nowhere..........
I've been using that exact drill!
Click to expand...

I remember my Dad showing me how he sharpen his drill bits... luckly I have both his bits and the table grinder and though now as good as he once did, I can put a reasonable new edge on a bit.
 
Do you happen to have reverseable drill and trying to drill them out in reverse? Seen it done when the heat goes up the attention to detail goes down. Rod
 
You can RUIN ANY BIT, by running them TOO FAST, common mistake!! Run them quite slow, with a FIRM pressure, to create a nice, constant cutting.
Bill W.
 
I understand the point of this discussion but am wondering why you would even bother to drill the rivets out? A good 1/8 inch punch will knock them out faster then messing around with drills.
 
The reason the drill bits want cut brass is it is slightly dull and the brass will form a sort of bearing surface. The same bit will still cut steal fairly good. Don't ask me how I know, have owned a machine shop for 32 years.
 
Mitch//pa said:
You guys need the doc
Click to expand...


I use my Drill Dr. a lot. Actually, I bought it with a friend and we share, since neither of us uses it all that much. It's a good investment-especially for medium size bits.

I always love the xenophobes who blame foreign made bits and other parts. You really mean "CHEAP"Chinese bits". Do you really think the Chinese-or the Taiwanese or anyone else could make all the things they sell to the USA with poor tool steel? They can certainly make quality tools, but if you buy them at Walmart, or ACE Hardware or, anymore, from Sears, you'll get a good price, but you'll get what you pay for.
 
This may come as a surprise to some of the people that have posted replies on this thread. You do sharpen a drill for brass a little differently. While you need proper clearance at the cutting edge you also grind or stone a slight neutral flat on the face of the cutting edge. Notice I said neutral not negative. Other wise the drill will screw itself into the brass. I do agree that it would be easier in the case of brake shoe rivets to use a punch to remove them. I learned how to sharpen drills in 1958 when I went to work in an automatic screw machine shop. I believe that I have sharpened more drills by accident than most machinist do on purpose. LOL
 
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