Has anyone made a long drill bit

[Gustavo Hoefs]

Zug says drill bits are graduated in hardness from tip to shank, I suppose an adjustable die would be appropriate. By adjusting the cutting depth and taking several passes it should make the procedure a success. I would imagine if the material is too hard for an HSS die then heating to draw a small amount of hardness out of the shank would not cause any difficulties later.

 

[Vaino]

I used a carbide tool bit to cut the drill shank for a slight press fit dia. which is pushed into the hole in the drill rod and both are soldered together. No need to chase and tap threads.

Grinding a flat bottom on the drill point is easy w/ the long length and have resharpened the flat bottom point a few times....very sharp cutting edges cut the hard maple like butter......Fred

 

[Rifleman1776]

OK, glad that worked for you. I have had several made (I'm not a welder). Brad points are my choice also. But ANY drill can drift off center. Drift is often caused by varying hardness in the wood and/or previously unknown tiny knots and irregularities. A bit welded to a rod requires the whole thing to be withdrawn periodically to remove shavings build up. A long drill factory made has fluts running the entire length just for this reason. A spoon bit is viewed by some as the best choice for drilling deep holes. Makers of bag pipes use spoon bits for their flutes as do some makers Indian flutes and more.

 

[ZUG]

No - the drill bit is not graduated in hardness -- the shank (where you chuck it up near the end of the flutes) is not hardened. I cut them with a regular H.S.S. lathe tool bit -- nothing special and I use a H.S.S. die to cut the threads also nothing special (use real cutting oil). Welding tool steel is not easy to get right you do get embrittlement if not done correctly. If you are using a torch then you may not have a "normal" flame set when welding and adding extra carbon to the welded joint increasing the chance of a brittle joint. Enough said -- there are far too many experts to discuss every option :v .

 

[Vaino]

Why chase and tap when a simple press fit and soldering does the job? Of course w/ a flat bottom point, sharpening is also simple...even w/ the long length. Just like to keep things simple .....Fred

 

[jerrywh]

The drills I solder never come loose. I got one or two that are 40 years old. Barrel sleeves are routinely held in with loctite. sleeves in diesel engines are also. Some of the sight ramps on modern guns are held on with Loctite. I wouldn't worry about a RR drill.