Speaking of high school shop class (mine was actually 8th grade)...

We had one of those square hole drilling bits. I was always amazed at that little invention. I thought "man whoever invented that made a lot of money"..

I have never seen one since... so I guess not.

Clearly, misunderstood
 

Twist Drills

The twist drill is one of the important, least understood, and most neglected of all cutting tools. Drill point standards are accepted based on inflexible precedent rather than logical deduction and experimentation. The 118-degree point, when the full length of the cutting for example, is erroneously assumed to be a good compromise or general-purpose point....http://http://www.hannibalcarbide.com/tech_support/drill_point_selection.php This is a contributing factor to the economic mess that we are in and will not escape. This nation was built on manufacturing and resource extraction, not on a service oriented economy. But then again, being an old skool type, what do I know?:rolleyes:

I agree- 118 is NOT the best drill point angle, but it is the most common out there for the reason of that's the way it's always been...

An older lady became a widow and needed to go back to work to pay the bills. She got a job in a hardware store, even though she knew almost nothing about hardware.
one day a guy came in and asked to see some files. he looked them over and said "I'll take that flat bastard".
She became very indignant and explained that she was a church-going christian and didn't appreciate foul language.
he explained that "flat bastard" was actually a name of a type of file and wasn't it foul language. She apologized and sold him the file.

A few weeks go by and another guy asks about files.
She says "how about this flat bastard? He says "No, I think I'll take that little round son of a beotch" ;)

It is surprising how many can't read a tape measure. "Two little lines past the middle one."

You don't hear "twist" drill bit too much but there are so many types like the ones pictured on the 1st page. There is no auger bit shown. Then there are SDS bits. It can get confusing.

Keep it simple. I walked into Lowes yesterday and asked the 20 something if polyester resin was in his dept (paint) and if so, where. He shrugged and said he didn't know. What is it used for? I told him like surfboard resin. "Oh, that's right over there on the left." :p

GTFO! I can't believe how many here didn't know what a twist drill was. No wonder ya'll are in off topic!

:p

I think it more likely you're just showing your age off troop. ;)

no, I think some of you we're just showing that you didn't know the correct name for a tool. :-)

The term, "twist drill" is the correct name whether you use it/know it or not.

The term, "drill bit" describes the general family of drills used to create holes in various materials. The twist drill is but one of many types.

http://en.wikipedia.org/wiki/Drill_bit

Sherwood

I have bought gillions of drill bits, you know i've never once seen "twist drill bit" on the package that i can recall.

I guess even the manufacturers don't know what they're called. :)

Whether or not you use the term, in fact it IS the correct term. See the post above yours.

You really have a gillion? If put end to end how far would that stretch?

They would stretch from here to the nearest push drill bit factory.

The correct term for fingers is phalanges, but no one calls them that.

I submit you'd find more people who knew what phalanges are then you would who knew precisely what a "push drill bit" was.

Hehe. :D

whatever.
;-I


Twist drill
The twist drill bit is the type produced in largest quantity today. It drills holes in metal, plastic, and wood.
The twist drill bit was invented by Steven A. Morse[1] of East Bridgewater, Massachusetts in 1861. He received U.S. Patent 38,119 for his invention on April 7, 1863. The original method of manufacture was to cut two grooves in opposite sides of a round bar, then to twist the bar to produce the helical flutes. This gave the tool its name. Nowadays, the drill bit is usually made by rotating the bar while moving it past a grinding wheel to cut the flutes in the same manner as cutting helical gears.
Tools recognizable as twist drill bits are currently produced in diameters covering a range from 0.05 mm (0.002") to 100 mm (4"). Lengths up to about 1000 mm (39") are available for use in powered hand tools.
The geometry and sharpening of the cutting edges is crucial to the performance of the bit. Users often throw away small bits that become blunt, and replace them with new bits, because they are inexpensive and sharpening them well is difficult. For larger bits, special grinding jigs are available. A special tool grinder is available for sharpening or reshaping cutting surfaces on twist drills to optimize the drill for a particular material.
Manufacturers can produce special versions of the twist drill bit, varying the geometry and the materials used, to suit particular machinery and particular materials to be cut. Twist drill bits are available in the widest choice of tooling materials. However, even for industrial users, most holes are still drilled with a conventional bit of high speed steel.
The most common twist drill (the one sold in general hardware stores) has a point angle of 118 degrees. This is a suitable angle for a wide array of tasks, and will not cause the uninitiated operator undue stress by wandering or digging in. A more aggressive (sharper) angle, such as 90 degrees, is suited for very soft plastics and other materials. The bit will generally be self-starting and cut very quickly. A shallower angle, such as 150 degrees, is suited for drilling steels and other tougher materials. This style bit requires a starter hole, but will not bind or suffer premature wear when a proper feed rate is used.
Drills with no point angle are used in situations where a blind, flat-bottomed hole is required. These drills are very sensitive to changes in lip angle, and even a slight change can result in an inappropriately fast cutting drill bit that will suffer premature wear.

Here, for crying out loud!
 

MSC #: 78568086

Precision Twist Drill
Qty: [Add item to list]
Quantity Break
Pricing:
1 - 11: $4.70 ea
12 - 35: $4.46 ea
36 - 59: $4.23 ea
60 +: $3.99 ea
In stock: 33
Mfr: Precision Twist Drill
Mfr #: 058128http://forums.pelicanparts.com/uploa...1237584858.gif:rolleyes:

I guess this terminology discusssion is better that thinking about the a--holes in washingtoon d.c.:)

all drill bit mfg, companies of said product refer to it as "twist drill" in their names. DeWalt catalogue calls them "twist drills".

Here is the McMaster -Carr catalog page
 

*
General Twist Drill Bit Information

About Twist Drill Bits

The size of a drill bit (its cutting diameter) may be listed in inches or millimeters, which corresponds to the actual drill bit diameter (e.g. 1/4" drill bit size has a 1/4" drill dia.), or may be designated by a letter or wire gauge number, which represents decimal sizes.
TWIST DRILL BIT STYLES

Specialty Drill Bits— Specialty drill bits include threaded shank twist drill bits and multi-diameter drill bits. See page 2393.
Reduced-Shank Twist Drill Bits— Called reduced shank because the shank diameter is smaller than the drill bit size (cutting diameter). They can drill holes that are larger than the capacity of the drill chuck. For example, our popular 1/2" shank diameter drill bits (also called Silver and Deming drill bits) can drill holes up to 1 1/2" dia. using drills with 1/2" capacity drill chucks. See pages 2394-2395.
Short Length Twist Drill Bits— Also known as screw-machine and stub-length drill bits, they have a shorter flute and shorter overall length than jobbers' drill bits for maximum rigidity and accuracy, as well as reduced deflection and breakage. Great for hand and machine drilling. See pages 2396-2397.
Maintenance Length Twist Drill Bits— Longer than short length drill bits for greater depth and shorter than jobbers' drill bits for increased rigidity. See page 2397.
Jobbers' Twist Drill Bits— The industry standard, jobbers' drill bits are the most widely used. They perform general purpose and heavy duty drilling with both portable and machine tools. We offer general purpose and heavy duty styles as well as deep-hole, left-hand, fast spiral, and slow spiral styles. We also have drill bits called aircraft jobbers' drill bits that are made to National Aerospace Standard (NAS) 907. See pages 2398-2408.
Long Length Twist Drill Bits— Also known as taper length drill bits, have a longer flute and overall length than jobbers' drill bits for drilling deeper holes. See page 2409.
Taper-Shank Twist Drill Bits— Longer than most long-length drill bits, we offer taper-shank drill bits in diameters up to 2 1/2". They fit directly into the spindle hole of a drill press or other machine tool having the same spindle taper as the drill bit. For a drill press or machine tool with a larger spindle taper than the drill bit, you can use a reducing socket or sleeve. See page 2412.
Extra-Length and Extension Twist Drill Bits— With lengths from 6" to 18", these drill bits can drill extremely deep holes and reach 0deep spots. See pages 2410-2411.
HIGH-SPEED STEEL AND COBALT STEEL TWIST DRILL BITS

General Purpose High-Speed Steel— Works well on a variety of materials including steel, cast iron, and forgings. Most have a standard 118° point.
Heavy Duty High-Speed Steel— More rigid than general purpose drill bits, use them for hard steel, stainless steel, titanium, and other hard materials. All have a self-centering 135° split point that won't skid or walk when starting a hole—a distinct advantage for jobs on drill presses where bushings can't be used. The point also allows faster penetration and produces smaller chips for better chip evacuation.
Heavy Duty Cobalt Steel— More durable than heavy duty high-speed steel drill bits, cobalt steel drill bits retain their strength and hardness at higher temperatures. They are more abrasion resistant and can withstand the heat generated when drilling high-tensile alloys, stainless steel, titanium, Inconel, and other hard to machine metals. Some have a straw-gold or bronze oxide color for easy identification. Most cobalt drill bits feature the 135° split point that won't skid or walk when starting a hole.
CARBIDE AND CARBIDE-TIPPED TWIST DRILL BITS

Carbide drill bits retain their hardness and sharp edge at higher temperatures than high-speed and cobalt steel drill bits, and have better abrasion resistance. Most carbide bit styles are used on abrasive materials such as cast iron, nonferrous alloys, hard rubber, plastics, glass, ceramics, and composites. For drilling steel, stainless steel, and high-temperature alloys, refer to our solid carbide straight flute, die, and high-performance drill bits.
We offer solid carbide drill bits as well as drill bits with carbide tips brazed to the end of a steel drill bit body. The advantage of solid carbide drill bits is their extreme rigidity, which results in greater drilling accuracy and an improved surface finish. Solid carbide drill bits also can be run slightly faster than carbide-tipped drill bits. When drilling with carbide, the machine setup must be as rigid as possible with no spindle vibration or end play. Using drill jig bushings is highly recommended. Whether you select a solid carbide or carbide-tipped drill bit depends on the material you're drilling and the economics of the application. See pages 2412-2419 for carbide-tipped and solid carbide drill bits.
Note: The shank diameter is the same as the drill bit size (cutting diameter) on all of our solid carbide and carbide-tipped drill bits, except for solid carbide square-die, carbide-tipped drill bits for glass and ceramics, and small dia. bits with 1/8" shanks.
SURFACE TREATMENTS AND COATINGS

Surface treatments and coatings improve the performance of drill bits.
Black Oxide— Also known as steam oxide or blue finish, this surface treatment has a dull, dark black or dark blue color. It retains lubricants for improved chip flow and increased abrasion resistance. It also relieves drill bit stress and provides additional tempering. Used on free machining steels, high temperature alloys, stainless steels, and cast irons. Note: Not recommended for most nonferrous materials.
Bright Finish— Surface is untreated. Polished flutes increase chip ejection in soft, ductile materials such as aluminum and other nonferrous materials. May also be used in ferrous metals, wood, and plastics where chips tend to cling to the tool surface.
Nitro-Carburizing— The surface treatment adds extra wear resistance along the cutting edge of the point. Drill bits also receive a low temperature stress relieving treatment for added lubricity. Drill bits will have a straw-gold or black and gold color.
Coatings— Coatings extend drill bit life by 300% to 800% compared to uncoated tools. Generally harder than the outer surface of the drill bit, coatings form a barrier against high temperatures and abrasion. They also improve the surface finish of parts and permit faster cutting speeds and feeds.
TiN (titanium nitride) coating is bright gold in color. It is for use on nonferrous and ferrous metals such as free machining steels, as well as nonmetallic materials and plastics. Drill bits with this coating may be used at speeds 50-75% faster than uncoated drill bits. Note: Not for use on wrought aluminum and titanium alloys.
TiCN (titanium carbonitride) coating is violet-gray or gun-metal gray or dark blue in color. It is intended for tough to machine steels, ductile cast iron, cast aluminum, stainless steels, high-temperature alloys, copper alloys, and titanium. Drill bits with this coating may be used at speeds 50-75% faster than uncoated drill bits.
TiALN (titanium aluminum nitride) coating is dark violet/blue-gray in color. Use for drilling stainless steel, high alloy carbon steel, and nickel-based high-temperature alloys. It's also highly effective for abrasive materials such as cast iron. Its high heat resistance may permit dry machining. Drill bits with this coating may be used at speeds 100% faster than uncoated drill bits.
Multilayer TiN/TiALN coating has a red-violet color. It has alternating ultrathin layers of coating that combine the universal applications of TiN, the shock resistance of TiCN, and the hardness and heat resistance of TiALN. :)

Maybe it is a regional thing. I grew up in south and would have been backhanded and called a Yankee if I ever used the phrase "twist drill".

I thought you were talking about a Yankee drill.
http://www.asktooltalk.com/images/ar.../pushdrill.jpg

Those contraptions are great at pinching fingers. I think Grant was going to flood all the hardware stores in the South with them, but then the war ended otherwise.;)