Questions about twist drills

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: Harold_V, websterz, GlennW

Posts: 970
Joined: Sat Jan 29, 2011 11:38 am
Location: NE Ohio

Re: Questions about twist drills

Postby earlgo » Tue Jan 10, 2017 12:04 pm

Harold_V wrote: Gunsmiths, using less than great lathes, have (successfully) drilled deep holes for a long time now, thanks to that technology.

True, but the very early guys hammer forge-welded a strip of wrought iron around a long mandrel, straightened the resultant tube, and then using primitive bits, bored the tube to size, and then rifled it, if required. I don't know when the high pressure coolant fed gun drill was perfected, but it was most likely not before the 20th century. (I didn't 'google' it so correct me please.)

Posts: 89
Joined: Tue Oct 20, 2009 9:39 pm
Location: Durban South Africa

Re: Questions about twist drills

Postby atunguyd » Wed Jan 11, 2017 2:38 pm

Harold, can you please elaborate on your warning earlier in this thread about using the side of the grind wheel and "horsing". I am not familiar with this term horsing and it seems a valuable warning.

Sent from my SM-N920C using Tapatalk

User avatar
Posts: 4191
Joined: Wed May 17, 2006 8:21 pm
Location: Phoenix, AZ

Re: Questions about twist drills

Postby BadDog » Wed Jan 11, 2017 4:01 pm

He's just saying it's ok to use the flat side of the wheel for light relatively gentle work when needed to provide a flat surface not easily achieved working on the circumference of the wheel where most grinding is done. If you get very aggressive using the side of the wheel, or start developing significant grooves, you risk breaking the wheel and causing damage and/or serious injury. It's also worth noting that beyond initial truing, cleaning and refreshing a wheel side should you dull it can also be problematic, so in my shop I use the side both gently and sparingly only as needed.
Master Floor Sweeper

User avatar
Posts: 6204
Joined: Sat Jan 17, 2009 7:55 pm
Location: Florida

Re: Questions about twist drills

Postby SteveHGraham » Wed Jan 11, 2017 4:17 pm

You just have to use common sense with abrasives. Like when I use a Dremel tool to remove calluses from my feet.
Don't trigger me, bro!

User avatar
Posts: 356
Joined: Tue Jun 28, 2011 9:19 pm
Location: USA

Re: Questions about twist drills

Postby BigDumbDinosaur » Wed Jan 11, 2017 4:46 pm

SteveHGraham wrote:You just have to use common sense with abrasives. Like when I use a Dremel tool to remove calluses from my feet.

Podiatrists use a Dremel-like tool to remove calluses and bunions, except theirs is made from stainless steel and probably costs thousands of dollars, being a medical instrument. :shock: As the old warning goes: trained professional, do not try this at home. :D
Science makes it known. Engineering makes it work.

Return to “General Discussion”

Who is online

Users browsing this forum: Harold_V and 12 guests