Unit 6 Drills
Vocabulary Notes to text I
hole – отвір
to drill holes
to bore holes
to produce holes
bar stock – заготівка у формі прутка
round bar stock.
steel bar stock
bar stock treatment
groove (syn. flute) – канавка
drill flute (groove)
spiral groove (flute)
to make flutes (grooves)
to mill – фрезерувати
to mill a flute (groove)
milled flute (groove)
milled hole
body – тіло, робоча частина (свердла)
body of casting
drill body
cutting edge (syn. lip) – ріжуча кромка, лезо
tool cutting edge
drill cutting edge
to remove – видаляти, знімати
removal – видалення
to remove chips chip removal
to remove material material removal
to remove stock stock removal
twist drill – спіральне свердло
twist drill application
twist drill body
twist drill groove
twist drill removal
shank – хвостовик
tool shank
drill shank
twist drill shank
taper shank
point – ріжуча частина
drill point
tool point
twist drill point
lip (syn. cutting edge) – ріжуча кромка, лезо
drill lip
drill lip treatment
drill lip length
web – перемичка
drill web
drill web work
drill web length
drill web strength
to grind (ground, ground) – шліфувати, заточувати
to grind the cutting edge ground cutting edge
to grind the tool ground tool
to grind the twist drill ground twist drill
proper – правильний, належний
proper speed
proper angle
proper treatment
straight – прямий
straight groove
straight hole
straight shank
straight shank drill
tapered (taper) – конічний, конусоподібний
tapered bar stock
tapered hole
tapered shank
tapered shank drill
taper bore
to clamp (syn. to fix, to hold) – затискати, закріплювати
to clamp the cutting tool
to clamp the tool shank
to clamp the drill shank
Read and translate text I
Drills
Drills are cutting tools used for producing holes of different diameter in metal or in any other solid material.
The cylindrical holes are produced in metal or in solid material by means of rotating drills held in the drill spindle of the drilling machine. The workpiece to be drilled should be clamped in the drilling machine table.
The most common type of drills is the twist drill made of a steel round bar stock. Twist drills are made with two, three or four spiral grooves or flutes milled in a cylindrical or flat piece of steel.
These grooves or flutes around the body of the drill serve for forming the cutting edges of the drill and for removing chips from the hole in the process of drilling. The drill flutes also serve for lubricating the drill.
The twist drill consists of a body, a shank and a point. The twist drill has two cutting edges or lips which are connected by a web. The web gives rigidity and strength to the drill. It does not cut metal. The lips serve for removing material from the workpiece.
To drill holes in metal the cutting edges (lips) should be correctly ground to a proper cutting angle. When the drill is ground correctly it will make holes of a proper diameter.
Drills have shanks of various types; the most common of them are straight and tapered shanks. The drill shank serves for clamping the drill in the spindle or in the drill chuck.
Task I. Fill in the blanks with the words given below:
twist, holes, cutting, point, grooves, lip, flutes, web.
In drilling ... in metal heavy pressure must be applied at the drill ... .
Spiral ... are part of most drills.
The ... angle at the outer corner of the ... should be about 12°.
The cutting edges of ... drills are connected by a ... .
The body of metal between the ... forms is called the web.
Task II. Translate into Ukrainian.
The drill flutes serve either to remove chips from the hole or for lubricating the drill. (lubricate - змащувати)
The workpiece to be drilled should be clamped either in a vice or in a chuck. (vice - лещата)
Either straight or tapered shank drills may be used for drilling.
Coolant is carried either through the drill shank or along the flutes. (coolant – змащувально-охолоджуюча рідина)
The twist drill is made either by cutting grooves in a flat piece of steel or by milling a cylindrical steel piece. (flat - плаский, mill - фрезерувати)
Vocabulary Notes to text II
single – один; одиничний
single point
single flute
single cutting lip
single-cutting drill
hollow – порожнистий
hollow shank
hollow drill shank
tubular (syn. hollow) – трубчастий, порожнистий
tubular shank
coolant (syn. lubricant) – змащувально-охолоджуюча рідина
coolant for the drill
coolant for the tools
to carry – нести; подавати
to carry coolant
to carry chips
to carry tools
to carry lubricant
to be designed to (for) – призначатися для
The drill is designed to drill holes.
The hollow drill is designed to remove chips through a hollow shank.
design – конструкція, проект
drill design
point design
shank design
enlarge – збільшувати, розсвердлювати
to enlarge the hole
range – радіус, діапазон
range of action
holes ranging from 1" to 3" in diameter
range of speeds
range of diameters
Read and translate text II
Drills
Different kinds of drills are used in drilling. They are single-cutting drills, hollow drills etc. Single-cutting drills axe less than 1" (inch) in diameter. They have a tubular shank with a single flute. Coolant is carried through the hollow shank and through a small hole in .the drill tip; the chips are removed through the single flute.
A hollow drill is designed to carry chips through a hollow shank. This tool is used for enlarging holes but not for drilling solid metal.
A two-lipped hollow type deep drill is used in drilling in solid metal ranging from 1" to 3" in. diameter and the tip is attached to a tubular steel shank. Coolant carries chips through the flute into the centre of the drill and then out through the hollow shank.
Drills of the same design are also used for holes larger than 3".
Additional Reading
Task I. Translate into English
Свердла це ріжучі інструменти, які використовують для виробництва отворів різних діаметрів у металах та інших твердих матеріалах.
Спіральні свердла мають спіральні канавки, які слугують для утворення ріжучих кромок свердла та для видалення стружки з отворів під час свердлення. Ріжучі кромки повинні бути правильно заточені.
Task II. Give a summary of the text.
Drilling
Notes
pitch – крок
helix angle – кут підйому гвинтової лінії
thickened – потовщений
resistant – стійкий
conventional – стандартний
oil – рідке мастило
tough – жорсткий
rigidity – жорсткість
increase – збільшувати
Only twist drills of high-speed or super high-speed steel should be used for drilling Nimonic alloys. The included angle of the drill tip can vary from 118 deg for Monel alloy 400 and Nickel 200 up to 135 deg for the Nimonic alloys.
A short pitch, helix angle of 35 deg, short polished flutes and thickened web are the characteristics of the drill that will usually give the best results. Although high-speed steel drills are usually used, on soft alloys, tungsten-cobalt (super high-speed) tools are used for the harder alloys.
Some alloys for which hand feed is recommended are resistant to the conventional high-speed steel drill. To drill such alloys a tungsten carbide tool is recommended. Also drills with oil holes for lubrication give good results on these tough materials. Drills and drill flutes should be as short as possible for rigidity.
When deep holes have to be drilled, a series of drills of increasing length should be used.
Task III. Read the text. Answer the question: What are the characteristic features of the new twist drills?
Modified to Drill Fast
Notes
rake angle – головний передній кут
split point – роз’ємна ріжуча частина
New high speed steel twist drills have a modified parabolic flute shape and a thicker web than conventional drills, so that greater depths can be drilled.
A higher helix angle and increased rake angle at the drill point also reduce cutting energy requirements. Length drills, in 29 sizes from 1/16 to 1/2 in., have a split point. Wire gage sizes range from No. 1 to No 52. Taper length, long flute drills also with split point, range in 34 sizes from 1/8 to 3/4 in.
Task IV. Translate without the dictionary.
Twist drills with a new treatment are made of HSCO (cobalt high speed steel). The drills are finished with a hard surface finish using a plasma process. The result is a drill harder than tungsten carbide which is expected to provide 400% more life and an improved hole finish.
Task V. Translate using the dictionary.
Carbide Insert Drills
Carbide insert drills can be used on NC lathes, chuckers, machining centres, turret lathes, engine lathes and drill presses for drilling carbon and alloy steels, austenitic stainless steel, cast irons and aluminum. These drills use industry standard indexable carbide inserts so they eliminate the need for separate predrilling operations and time for regrinding and replacement.
Drilling at carbide speeds translates to improved penetration rates. For example, in 1040 steel, rates of 5 to 7 inches per minute for regular length drills, and 10 to 12 inches per minute for stub length drills are not uncommon. When the drill is rotating, the spindle must run true and concentric. It is important to use only inserts specified for each drill.
Task VI. Translate without the dictionary.
I. Indexable - Carbide - Insert Drills
Introduction of indexable-carbide-insert drills is one of the most significant developments of the past decade. Engineers say that indexable-insert drills take advantage of the high cutting speeds to permit machining rates up to ten times faster than conventional high-speed-steel twist drills. Indexable-carbide-insert drills make productivity increase and reduction in tooling costs possible.
Indexable-insert drills consist of a cylindrical body having two straight chip flutes with coolant holes. From one to three indexable carbide inserts provide the cutting edges. The drills are available in a range of standard sizes from 5/8 inch to 3 inches in diameter, and are capable of drilling holes up to 2 1/2 times drill diameter.
II. Diamond Tooling
In the automobile industry aluminum is used to reduce car weight. Aluminum alloys with silicon content for strength are used for making engine blocks, cylinder heads, transmission cases, etc. Such alloys are cut by diamond cutting tools. Standard milling cutters with design modifications for optimal performance with diamond-tipped indexable carbide inserts have only recently been made available. The superiority of diamond in machining high-silicon aluminum is clear.
Task VII. Translate the text using the vocabulary notes:
Vocabulary Notes
boring bar – борштанга
insert – вставляти; вставка
replaceable insert – змінна вставка
inserted blade – вставний різець
NC – numerical control – числове (цифрове) програмне управління
index – повертати
to index the workpiece
indexing time
indexing table
shift – зсувати, переміщувати
to shift the workpiece
to shift the insert
to shift the cutter insert
Boring Bar
Boring bar holds two cutters. Small-hole tooling operations that normally require two separate tool stations can now be performed from a single station with this double-ended small hole bar. It has two replaceable inserts that can used to bore and thread, bore and groove, groove and thread, or groove two different width. This combining of operations is said to improve productivity on NC equipment by reducing tool indexing time. A special clamping design prevents the cutter insert from shifting.
Grammar notes to the text.
Конструкція типу: - The lathe is said to be used for different operations. - перекладається: Говорять, що токарний верстат застосовується для різних операцій.
Task VIII. Translate into Ukrainian.
The boring tool is said to be made in high speed steel.
The tool diameter range is said to be divided into 12 groups.
A special clamping device is known to be used in the lathe.
This device is known to improve productivity on the new equipment.
This combining of operations is said to improve productivity on the new equipment.
Task IX. Give a summary of the text.
Drills with Inserts
Carbo-drill indexable drilling bars use a triangular insert to cut to the centre and a square insert to cut the balance of hole diameter. Larger drills require an additional square insert to lengthen the cutting edge to cover hole size. Design permits use of standard inserts. Sizes range from 1 in. to 3 in.
Task X. Translate the text with the help of a dictionary.
Boring Tool
A new spiral boring tool is a roughing tool for the opening cut of predrilled holes in steel, cast steel, cast iron and other metals.
The complete tool consists of a holder with a rotating guide bush and a detachable boring tool.
Tools are made in high speed steel in sizes from 28 to 200 mm Ø. Tool diameter range is divided into 12 groups. There is only one holder to each group.
Task XI. Read the text. Translate it with the help of a dictionary.
Cuts Keyway Range
A broach set for cutting 1/8, 3/16, 1/4 and 3/8-in keyways contains four high-speed steel push - type broaches, guide bushings and all necessary shims. The Nо. 10-10А set cuts keyways in 36 combinations using 18 bushings with diameters increasing in 1/16 in increments from 1/2 to 19/16 in. Also available are sets with larger or smaller broaches to extend the range of keyway sizes from 1/16 to 3/4 in. in bores from 1/4 to 3 in. The broaches can be used with any hydraulic press.