What kind of tool is used for tapping male threads
Types of threading dies, their sizes.
A tap, sometimes called a lerka, is a tool for tapping male threads. There is also an internal one, it can be threaded by means of a tap.
Types and sizes there are many, in greater detail consider the basic types, those that are most commonly used in both everyday life, and in manufacturing.
All dies are used jointly with a strip lock. a clamping tool,
suitable for several thread diameters. For example, for small (up to 10mm), for medium (12mm to 24mm), for large (27mm to 42mm). Slot is inserted into holder and tightened with screw, special recess for screw.
Metric dies. As the name suggests, they are needed for tapping metric threads. measured in millimeters, the letter “M” is present in the marking.
For example: M8 or M10 means you can thread at 8mm and 10mm. Sizes range from 1mm to 60mm, t.е. It is possible to cut almost any thread in diameter.
Thread pitch. distance between coils. Each die has its own base thread pitch. In addition to the main one, there are a few extra ones, but the extra one is always smaller than the main one. Here is an example: take the M12 strip. Her basic pitch is 1.75. Also available in (M121.5) (M121) (M120.75) (M120.5). The shallower the pitch, the closer the coils are to each other. Here’s an example:
Left side dies. They’re needed to cut the left-hand thread. Used quite rarely, e.g. in connections that rotate. And if there were right-hand threads, they would unscrew. The chuck of the drill is screwed in with the left-hand thread. These are marked with “LH” in Latin.
Pipe dies. Not to be confused with metric, there is a “G” in the marking.
If it is a pipe thread, then 90 percent of the time you need it. Pipe threads are measured in inches, not millimeters, t.е. A different measuring system is used. One inch is 25.4mm If converted to millimeters, we have: A small table, translate millimeters into inches: 15mm pipe. ½ inch 20mm. ¾ 25mm. 1 inch 32mm. 1 ¼ For example: G 1/2, G 3/4. these dies can be threaded half-inch and three-quarter, this is the most common and frequently used sizes, used for residential water supply systems. Sizes: 1/8 to 2 in.
Tapered (inch) pipe. Used for getting the thread under a cone. Used primarily in manufacturing, for fuel lines, machine tools. In the marking there is the letter “K”.
Quality. Dies are made of high-speed steel such as R6M5, 9HS, HSS (most common on sale), much less frequently R18, which has been around since the Soviet Union. In general, any since those times, if you found one, take it, the quality is good, and if it has a quality mark, then it’s perfect,
last a long time. Although their appearance is not usually merchantable, may even be rusty, but there’s nothing wrong with it. Among the modern manufacturer of well-proven plant “tulamash”, Lviv instrument plant.
Approximate in 2012: M8. 50 rubles M14. 70 rubles M27. 210 rubles M48. 550 rubles
Working part of a strip (fig. 3.94) consists of two parts fence and gauge. The pick-up part is tapered with a 4060° angle, it is located on both sides of the die, and its length is 1.5 to 2 threads. The calibration part usually consists of 3 5 turns.
When tapping external threads by hand, different designs of dies are used: round dies, sometimes called lancers, sliding dies, and special dies for tapping pipes.
Round dies (lerki) (see: “round dies”, “lerki”). Fig. 3.94) are threaded rings with several grooves for formation of cutting edges and output of chips during thread cutting. One-piece and two-piece inset dies are manufactured as solid or split, spring-loaded dies (Fig. 94). Studs are threaded manually with dies, or with special mandrels on boring machines and lathes. Split dies allow, thanks to their spring characteristics, to regulate the size of the average diameter of the thread.
Bits are made of 9ÕÑ and ÕÂÑÑ alloy tool steel or high-speed steel.
Square (sliding) strip (fig. 3.95) consists of two halves, strengthened in a special frame with knobs, the angular tabs of which enter respectively into the grooves of the die, holding its halves. One of the halves of the dies can be moved to set the die to the required mean thread diameter. Slotted tool is fastened with screws. These dies are seldom used nowadays for tapping, since they do not provide sufficient threading precision.
plate is fastened by means of screws. Threading with such dies is currently carried out quite seldom. since they do not provide sufficient threading precision.
Screwdrivers for circular dies (fig. 3.96) is a round frame with a recess, in which hole is set a round die. The strip is held in the hole by three locking screws whose tapered shanks fit into the recesses on the formative surface of the body of the strip. The fourth screw allows the average thread diameter to be adjusted.
The tool and process of tapping external pipe threads (Fig. 3.97). The most common way of cutting pipe threads is with sliding rams. The clupp is provided with a set of dies for 1/2″, 1/4″ and 1/22″ tubing threads.2 in. and is designed so that four inserts 5 moving in its housing 1 can simultaneously approach or depart from the center. The die movement is provided by a special rotating device of the claw face, driven by the crank 4. Precise setting of dies to the size of the thread is carried out by the limb on the clip body and setting movements occur by means of a worm gearing 3. After setting the dies to the selected thread size, their position is fixed by pressing a special stop “doggie”. After threading the tongs are not unscrewed from the treated workpiece, but the dies are moved apart by turning clamp knob 4 and removed from the treated workpiece. In addition to the cutting dies, there are three guide dies (smooth, unthreaded). They ensure steady positioning of the tongs on the pipe during machining and they are set by turning the worm screw of gear 3. Pipe sizes one inch and smaller are threaded manually with special pipe round dies.
When threading pipe, consider how the pipe is joined. When threading a permanent pipe joint, the length of the cut part of the pipe shall be 1/2 the length of the connection socket minus the thread length per 1-1.5 threads. When tapping collapsible pipe joints, the threads on one pipe shall be tapped as for permanent joints and the other end of the pipe shall be the sum of the length of the collar and locknut minus 1-1.5 times the thread length for the specified thread.
Thread-cutting round chasers (Fig. 3.98) are used for tapping pipe threads on metal-cutting machines (lathes and drills) using special chucks. There are sets of four dies, the threads of each die are shifted with respect to the previous one by 1/4 of a thread pitch.
Special self-tapping screwdriving heads are designed for thread cutting with the help of combs (Fig. 3.99), in which all four heads of the set are installed.
When tapping external threads on drilling machines and lathes, a special device with automatic feed cutoff is used (fig. 3.100). The fixture consists of a shank on which a sleeve with pressed in pins 2 is mounted. There are screws 4 screwed into the sleeve, the ends of which can fit into the holes of the socket 5. Inside the socket there is an adjusting screw 6. The strip is fixed with a screw in the housing seat 1. The fixture is installed either in the hole in the spindle of the drilling machine or in the hole in the trailing headstock of the lathe. During machining the end of the rod to be machined comes out of the die and rests against the end of screw 6, forcing it to move inside the shank. There is a socket 5 screwed on the screw which compresses the spring by moving together with screw b. The movement of the sleeve 5 is transferred via screws 4 to the sleeve 3, which moves on the outer surface of the shank until the pins 2 come out of the holes in the body. At the moment the pins 2 leave the body 1, it starts to rotate with a ram installed in it. By switching machine rotation into reverse, dies are removed from the cutting zone. By adjusting the screw outflow from the socket it is possible to cut threads of different lengths.
In thread cutting, coolant is used to improve the working conditions of the tool, reduce the roughness of the machined surface, and therefore improve the quality of the threads produced during thread cutting. The choice of coolant depends on the material of the workpiece. For example, for cooling steel (structural, tool and alloyed steel), cast iron, copper and aluminium, emulsion is most commonly used. In addition, kerosene is used to cool cast iron and aluminum.
Thread cutting in copper, brass and bronze can be carried out without cooling.
The design of the tap, a tool used to cut male threads, is essentially the same as that of the tap. While the tap is a hardened steel screw with grooves cut along the shank, the die is also a hardened nut with chisel grooves that form its cutting edges
The working part of the tap consists of a fence and a gauge part (fig. 1,а). The intake part has a cone with an angle of cp = 40 to 60°. When tapping the thread up to the stop on the shoulder of the screw f = 90°. The tapping part is located on either side of the die: its length is P/r-2 coils. Calibrating part length I (Fig. 1, d) contains usually 3-5 coils.
Back angle of round dies is taken as 7-8°. The anterior angle y for steel is 10-t-25°, for cast iron y=10-t-12°, for brass y.20°.
Various designs of dies are used: round dies (sometimes these dies are also called lerks), sliding dies (clip-type) and special dies for cutting pipes. In turn, round dies are divided into solid and split (spring-loaded).
One-piece dies are used for tapping threads with up to 52 mm diameter in one pass (fig. 1,а).
They are very rigid and provide clean threads, but wear out relatively quickly.
Slotted (spring-loaded) dies have a slot from 0,5 to 1,5 mm (fig. 1.6), which makes it possible to adjust thread diameter within 0.1-0.25 mm. Due to the reduced rigidity of dies, the threads cut with these dies do not have a sufficiently precise profile.
Sliding (prismatic) dies, unlike round dies, consist of two halves, called half-plates (Fig. 1,б). Each of them has a thread diameter and numbers 1 and 2 indicating their position in clamping. On the outside of the half-dies there are 120° angled grooves where they are fitted onto the corresponding tool shoulder (guide) of the tool. Between the half-plates and the screw is placed a binder, which serves for equal distribution of screw pressure on the half-plates.
Sliding half-plates are made in sets of 4-5 pairs in each set, each pair is inserted into the clip as required.
Plates. This tool is a one-piece or split ring with a screw thread in the inner cavity, which is used to cut the outer thread by screwing it onto the workpiece. Subshafts have a fence and a gauge.
There are many kinds of dies. Circular, square and hexagonal dies are used in metalwork, as well as sliding dies for locksmith’s tongs.
A round die, or lance, is a circular ring with a threaded hole and several grooves for forming cutting edges and removing chips during thread cutting. Round dies are solid and split (spring-loaded). The threads on the bars are cut with round dies in one pass by hand with a crank or on a lathe. Dividing dies, because of their spring-loaded nature, allow small adjustments in the size of the thread being threaded with a given die.
Square and hexagonal dies differ from round dies only in external form.
Fig. 3 shows a sliding prismatic die. It consists of two halves, which are fixed in a clevis (special frame with handles). The corners of the clip enter correspondingly into the grooves of the die holding its halves. One of the halves can be moved to bring the stock to the desired thread diameter. The fixing of the strip is made with a screw.
What tool is used for cutting male threads?
On the TV-7 lathe, the following operations can be performed:
A) turning, threading, and milling;
B) turning, drilling, threading, boring;
B) turning, drilling, groove milling, grinding.
On which of the listed machines the basic movements are performed: rotary and progressive movements of the tool?
Give definition of an error in a caliper.
List the methods of control of holes, give examples
Sawing surfaces at an angle of 90 degrees.
Dimitrovgrad Technical College Regional State Budgetary Vocational Education Institution
|Reviewed at the meeting of the Central Committee “Disciplines of the professional cycle “Welding Production”, “Construction and Operation of Buildings and Structures”, as well as the adapted programs for people with disabilities” Chairperson of the Central Committee Э.И.Shafieva Signed Minutes of the Central Committee meeting №_ of “”20||Examination MPK 05.01.Electric welder manual welder 22.02.06 Welding fabrication SP-21 Group Option||APPROVED by Deputy Chairman of the Board of Directors. Director of Stage Management _ R.Н. Baigullov “_” 201_.|
What are the different types of markings and in what cases are they used??
B) Linear, planar, spatial. Linear is used. when cutting shapes.Plane marking is used when sheet metal parts are processed.Spatial is the most complicated.at different angles.
B) For the application of vertical and horizontal lines;
What equipment and devices are used in marking?
B) Plates, reamer, coreer, scribing compass, ruler;
C) Table-drilling machine, complete with a vice and a sheet bender.
The property of metal to return to its original shape, after the cessation of external forces is:
The corrosion resistance of metal, is:
Which of the following properties must necessarily have metal for making rivets:
Steel, is an alloy of iron and carbon, where:
Roofing steel, this is a sheet metal thickness:
Metal property. hardness, refers to:
B) chemical properties. D) to keep the specific weight.
Thermal treatment of steel, which makes the product more hard, is called:
Give definition of the error in the locksmith’s ruler.
List methods of determining the quality of sawing
Sawing of flat surfaces.
Regional state budgetary professional educational institution “Dimitrovgrad Technical College
|Reviewed at the meeting of the Central Committee “Disciplines of the professional cycle of specialties “Welding Production”, “Construction and Operation of Buildings and Structures”, as well as the adapted programs for people with disabilities” Chairperson of the Central Committee Э.И.Shafieva Signed Minutes of the Central Committee meeting #_ of “20||МДК 05 exam.01.Electric welder manual welding 22.02.06 Welding production SP-21 Group Option||APPROVED by Deputy. Director for Learning and Development _ R.Н. Baygullov “_” 201_ year.|
A) Measurement is the process of determining the thread pitch.
B) Measurement is finding a value of a physical quantity by technical means.
THREADING AND THREADING TOOLS
Tapping is the creation of a helical surface on the outside or inside cylindrical or [-tonic] surface of a workpiece.
What tools are used to cut a helical surface on the outer cylindrical surface of a workpiece??
Threading on bolts, shafts, and other external surfaces of parts can be done manually or by machine. Hand tools include: round cut and uncut dies, and four. and hexagonal inserts, tubing tongs for tapping pipes. Inserts and dies are used for fixing dies. A round die is also used for machine tapping.
The number of chip holes d depends on the chip thickness azt removed by the teeth of one hole, the angle of the fence cone f and the thread pitch t:
As the number of chisel holes g increases, the thickness of the chip ag decreases and vice versa.
Depending on the diameter of the thread to be tapped, the number of tap holes ranges from 3 to 14.
The male threads may be tapped by turning lathes with thread cutters, chasers, threading dies with raked heads. 76 with dial, tangential and circular combs, whirling heads, as well as on drilling machines with tapping heads, on milling machines with thread cutters and on thread grinding machines with single- and multi-threaded discs.
The external thread surface can be obtained by thread rolling with flat dies, round rollers on thread rolling machines. Threading application. Thread rolling dies with axial feed enable turning of external threads on drilling and turning machines.
To name a tool for tapping threads in holes.
Threading in holes is carried out by hand and machine taps. A distinction is made between cylindrical and tapered taps. Manual taps are single, two-piece and three-piece. Usually a set consisting of three taps is used: a rough one marked with one line or number 1, a middle one marked with two lines or number 2, and a finishing one marked with three lines or number 3 (tab. 12, fig. 29).
As gauge and runner
For coarse pitch metric threads 6-24 mm For x/4-2″ inch threads For 4″ pipe threads
For coarse pitch metric threads 24-52 mm diameter For hard-to-machine metals, regardless of thread diameter and type
There are special taps: for tap (tap taps with a long cutting part), for nuts, for pipes, for light alloys, and with a conical working part. Taps are used to tap threads in through holes and blind holes or to calibrate previously tapped threads with a master tap. 77
A screwdriver with a fixed or adjustable square hole is put on the shank of a hand-held tap that ends in a square head.
In some cases, combination taps are used that can be used for drilling and tapping.
Machine taps are used on all types of drills and lathes to tap internal threads. They can be used to thread in one or more passes
Passes. Up to 3 mm pitch can be tapped in one pass and coarser pitches, very long threads and smooth threads in difficult-to-cut materials can be tapped in 2-3 passes, regardless of pitch.
Nut taps are used to thread nuts on machine tools. They work without reversing and are threaded on the shank when threading the nut. A distinction is made between straight and curved taps.
The elements of a tap are the working part, which consists of a cutting part, a gauge part and a shank. T8 working part has a spiral thread and longitudinal grooves for chip removal. Cutting edges are created at the intersection of the helical rifling and the longitudinal chip removal grooves. Tail ends with square die head for chucking. Taps are made of carbon tool steel U12 and U12A, high-speed steel R12 and R18, alloy steel Kh06, XB, TX.
What is a helical surface? A helical surface is a surface described by a curve that rotates evenly around
axis and simultaneously performing uniform translational motion along this axis. For a threaded surface, the formations are triangular (for metric and inch threads), trapezoidal (for trapezoidal threads) and rectangular (for rectangular threads, such as in jackscrews).
The thread profile is the contour obtained by cutting the helical surface by a plane passing through the screw axis.
The thread profile is made up of protrusions and troughs of the coils. The shaft axis is the axis of the thread surface
What parameters define the thread in each screw and each nut?
The parameters of a thread are the outside diameter d, the inside diameter du, the average diameter d%, the pitch I, the thread profile angle os. The thread profile is divided into two parts: protrusions and troughs. Threads can be single threaded and multiple threaded.
The thread pitch should be understood as the progressive movement of the center point of the formative profile, corresponding to-
which corresponds to one complete revolution of the thread in relation to the axis of the thread.
The thread pitch is the distance between the axes of two identical points of consecutive threads. or the distance by which a nut travels over a screw in one complete revolution for a single thread (Tables “taps” and “screws” in the table). 13 и 14).
What is the stroke of a multiple thread?
The helical surface of a multiple thread can be thought of as several helical grooves having
a. triangular; b. trapezoidal symmetric; c. trapezoidal asymmetric; d. rectangular; e. semi-circular.
Pdin nominal diameter (hence one nominal pitch, which in a multiple thread is called the pitch t) and formed on the same smooth cylindrical surface with evenly spaced starts. Thus, the thread stroke t is the distance between the nearest homonymous sides of a profile belonging to the same helical surface, in a direction parallel to the axis of the thread. Stroke of a thread is the relative axial movement of a screw or nut per revolution.
What is the relationship between thread stroke and thread pitch?
If the thread is single threaded, the thread stroke t equals the thread pitch P. If the thread is multi-turn, then the thread stroke t is equal to the product of the pitch P by the number of starts n:
Threading with a die
Formation of pupils’ ideas and skills of consecutive threading.
To teach students how to thread externally by hand using special tools and devices.
Correction of thinking through corrective and developmental task; memory in recalling the rules of T.Б.General and fine motor skills in practical work.
To develop a careful attitude to the tool and economical use of material.
Stage of psychological preparation of students for the main task of the lesson.
At practically every lesson, when making drawings, practical parts, you resort to mathematical operations. Calculate the length and height of the product
Assignment: decipher the word (thread)
Revitalizing your background knowledge.
Stage of preparation for conscious assimilation of the material.
Why do you think I coded this word in the table??
Repetition of what we have learned.
Repetition of the technological operations performed at the last lesson.
Municipal state special (correctional) educational institution
For pupils with disabilities
“Kulebaki special (correctional) boarding school type VIII”
“Threading with a die”
Ф.И.О. Dmitry Vladimirovich Shvetsov. Locksmithing teacher of the boarding school of the VIII-th kind.
Theme of the lesson: Threading with a die.
Equipment of the lesson: “Elements of thread”, “Threading tool”, vocabulary words, table, die, file, oil, metalwork tools, computer with a multimedia projector.
Basic terms: die, die holder, fence part, calibrating part, chamfer.
Objective: develop students’ understanding and skills for consistent threading.
Teach students how to thread male threads by hand using special tools and devices.
Correction of their thinking by means of corrective and developing tasks; their memory during recalling the rules T.Б.; general and fine motor skills in practical work.
To bring up careful attitude to the tool and economical use of the material.
Methods and techniques: explanation, conversation, storytelling, using visual didactic material, performing exercises and tasks.
Psychological peculiarities of age:
Children with disabilities. Grade 7 students. The level of intellectual development varies among the children.
All mental processes: perception, attention, memory thinking impaired.
The stage of psychological preparation of pupils for the main task of the lesson.
In almost every lesson, you resort to mathematical actions when making drawings, hands-on making parts. Calculating the length, heightof a product
The duty officer calls the date and the absentees.
Decipher the word “thread” from the table.
Everything You Need to Know About Taps & Dies. Gear Up With Gregg’s
Preparation stage for conscious learning.
Why do you think I coded this word in the table??
-What threads can be made in the direction of the coils?
-How and with what we measure the outside diameter of a thread?
-What tools are used for threading?
Repetition of the technological operations performed in the last lesson.
What tool did we use for the job??
Name the next operation we will perform?
Show and name the tools: ruler, square, compass, hacksaw.
Stage of including students in the activity to achieve the cognitive, developmental and educational goal of the lesson.
In today’s lesson, I will introduce you to the purpose and technology of threading by hand. You will also learn the tools you need for threading.
In the future independent life, especially for men, this knowledge is necessary both in everyday life and for the future profession. Just think about how necessary threading is. Look around you: tables, chairs, machines, cars, etc.д.impossible without a threaded joint. Our country has always been famous for its highly skilled specialists, who worked in huge factories and supplied products to all corners of our immense Russia.
-Teacher’s story (accompanied by a demonstration)
Special threading tools are used for cutting triangular external threads. dies. A round die is made in the form of a round nut (see “Threading a nut” on page 25). poster). Threads of a die are crossed by continuous longitudinal holes. They are used to form wedge and groove-shaped cutting edges on the threads of the strip, which allow cutting and chip removal at the same time. On the end faces, dies have a slightly lower thread profile height. This part of the die with incomplete threads is called the fence part (see “Threading”). poster). The part of a full-threaded die is called a gauge die (see. poster). The fence part allows you to start cutting with a shallow helical groove, and then move on to cutting it to the full depth of the gauge part. Threads of the same size can also be produced with a tap of the same size. A special tool is used for tapping with a tap. a tap holder (see table). The plate), which consists of the body, handles, locking screws. Insert flat to the body of the strip tool holder. Tap is fastened with locking screws. To cut an outside triangular thread with a round die, first determine the diameter of the rod for this thread and select the blank. The diameter of the rod to be threaded is selected in accordance with special tables (see Threading tables). table). The workpiece is clamped in a vice so that the protruding part of the rod is 20 25 mm longer than the length of the rifled part and is set at right angle to the jaws of the vice. To make it easier for the fence part of the strip to cut into the metal, on the end of the workpiece a chamfer is made with a file. Then work tool is prepared. Insert slab in strip tool holder. it is positioned so that the branding is on top and the recesses are located against the middle screw. Lubricate the shaft of the workpiece with machine oil. A die is placed horizontally on the end of the workpiece with the branding downward. Pressing with right hand palm on toolholder body, rotate it clockwise with left hand by knob until tool is fully inserted. Then take the handles of the strip tool holder with both hands and make one and a half turns clockwise and one and a half turns counterclockwise to thread completely. Turning counterclockwise remove whittle head with die from workpiece. The simplest way to check if a thread is being threaded correctly.is to screw on and remove the corresponding nut. If the nut moves quite freely and tightly on the thread, the thread is properly tapped.
As you listened to my explanation, you probably noticed the new words. They are located on the board. Let’s go over these terms in more detail.
Dictionary work. dies (special threading tool), dies. The fence part, the calibrating part, the chamfer
Plan.Concept: “Tapping a fastening thread
We pay your attention, that according to the Federal law N 273-FZ “About education in the Russian Federation” in the organizations which are carrying out educational activity, training and education of students with HIA is organized as jointly with other students, and in separate classes or groups.
Theme of the lesson : Threading a fastener with a hand tool.
Educational : familiarize students with the types of fastening thread, hand tools for tapping internal and external threads.
Educational: to promote the education of students, responsibility and accuracy.
Developing: promote the development of cognitive interest in the subject of technology.
Vocational: to familiarize students with the profession of a toolmaker.
Type of lesson : the lesson of discovering new knowledge.
- Types of fastening threads;
- Types of threads by profile;
- How threads are marked on the drawing;
- Tools for tapping external and internal threads;
- Methods of working with a thread-cutting tool;
- Safety precautions when working with thread-cutting tools.
- Distinguish types of threads by profile;
- Determine the pitch of a thread;
- Select and set up threading tools for tapping male and female threads.
Equipment: PC, projector, multimedia screen, CD with videos about occupations, samples of fastening threads, threading tools.
Interdisciplinary connections: mathematics, career guidance
Intrasubject links: organization of the workplace, H&S when working with metal, classification of steel
Technical Work: 7 grade. Textbook for secondary school students. / П. С. Samorodsky, A.Т. Tishchenko. В.Д.Simonenko.- М.: Ventana. Graph, 2011.
Technology of metal processing: Textbook for students in grades 5-9 of secondary schools / E. М. Muravyov 4th ed М.: Prosveshchenie, 2001.
Repetition of the lesson. 5 min.
Checking students on the logbook and readiness for the lesson
Repetition of the material “Methods of operation on a screw-cutting lathe”
1) To accommodate the front headstock, tailstock, and caliper
2) To accommodate the speed box, threaded spindle to which the chuck is screwed
1) To clamp the cutting tool in the toolholder and to move it through the feed
2) For fastening the measuring tool
3) To convert the rotation of a screw or shaft into translational motion of a slide with a tool
3) For turning the workpiece to a predetermined length
2) Passing, undercutting, cutting, slotting, boring, threading, shaped
These are helical grooves and ridges (coils) formed on a rod or in a hole.
External and internal, right and left, coarse and fine, metric and inch, single and multiple threads.
Thread profile can be seen when viewed from the side. it will reflect the outline of the threads.
Slides. 7, showing samples of threads by profile.
Triangular, rectangular, trapezoidal, trapezoidal, round
§ How do you draw the fastener thread on the drawing??
The outer diameter of a fastening thread is shown with a thick solid line, and the inner diameter of the thread is shown with a thin solid line.
§ Which threading tool is used for tapping male threads?
Dies (solid, split, threaded, prismatic), die holder.
§ How fastener threads are tapped on the stud?
Clamp the workpiece vertically in a vice and chamfer it with a file.
Lubricate stem with machine oil. A flat die with a ramlock is applied to the top face of the stem and turned with moderate pressure, without tilting. Turn the thread cutter as follows: one to two clockwise revolutions and half a turn in the opposite direction to break the shavings. Check the thread quality by screwing the threaded pin in.
§ Which tool is used for tapping internal fastener threads?
§ How do you thread the threads in the hole??
Clamp the workpiece with the bore in a vice. The working part of the tap should be lubricated with oil. Place a tap with a collar vertically and without tilting into the hole to be tapped. Hold the left hand on the workpiece and turn the crank clockwise as you turn it smoothly until the tap is firmly and steadily in contact with the metal. Then grasp the screwdriver with both hands and turn it gently: one or two turns clockwise and half a turn anticlockwise. Check thread quality by screwing the appropriate bolt into the hole.
Slide 6 Safety Precautions for Tapping Fasteners.
§ Use a brush to remove chips from the tool
§ Do not check the thread quality by touching it with your fingers
§ Make sure that the tap is not tilted
People of what occupations thread the fastener?
Toolmaker, Turner, Plumber, Automobile Locksmith.
Showing a fragment from the video “Toolmaker Locksmith
§ Which tools are used for tapping internal threads § Which tools are used for tapping internal threads
§ What kind of tools are used for tapping male threads § What kind of tools are used for tapping male threads?
§ Which tool is used for tapping internal threads?
§ Why do you have to lubricate a tapping tool??
Today we studied the topic of “Threading fasteners with hand tools”. We learned about types of threads and threading tools and how to thread on a rod and in a hole.
Presentation on “Threading
We pay your attention that according to the Federal law N 273-ФЗ “About education in the Russian Federation” in the organizations which are carrying out educational activity, training and education of students with Habilitation is organized both together with other students, and in separate classes or groups.
Description of the presentation on individual slides:
The most common threaded connections are. Their use is due to their simplicity, reliability, ease of adjustment, possibility of development and swivel assembly without replacing parts.
Depending on the surface to be threaded: Outer (screw, bolt) Inner (nut)
depending on the number of starts Single start, Multi-start, Formed by 2 or more helical lines Formed by one helical line
You have to look at the beginning of the coil and you can see how many coils have a beginning.
According to the direction of the helical line right left if the helical line rises from left to right t.е. Counterclockwise if the screw line rises from right to left i.e.е. clockwise To tighten a screw or nut with this thread. they have to be rotated to the right. т.е. clockwise To screw in a screw with this thread or a nut. they must be rotated to the left t.е. counterclockwise
4.According to the shape of the profile threads are:.triangular.Rectangular (non-standard, unstable, approx.seldom).trapezoidal ( screws, presses).Thrust ( jack) high force.rounds (pipes) provide.sealing
Depending on the size system metric inch pipe
Metric (for example, M10x1,5. fine pitch and M10. coarse pitch). pitch. distance between two points of neighboring threads. the number is the diameter of the thread.
11/4 inch ײ. Unlike metric, square is separated by the angle at the apex (65o). Diameter of thread expressed in inches Pitch is determined by the number of threads to one inch For example 11/4 ײ. the outer diameter of the thread in inches 1 inch equals 25.4 mm Thick pitch is different from the metric. It is not allowed in our country, but it is used for the production of spare parts from other countries.
Pipe threads differ from inch threads in that. that its original size is not the outside diameter of the thread, and the diameter of the hole in the pipe. For example ¾ ײ (the digits indicate the inside diameter of the tube in inches). Pipe threads are fine inch threads.
With machine tools With drilling machines With special tapping machines With lathes Rolling (with rolling dies and rollers)
Tapping by hand Internal threads are tapped with a tap Tap outer threads are tapped with taps
A tap has two main parts: the working part and the shank. Slitting grooves are used to form cutting points and chips to be cut during cutting
Depending on thread profile Hand tapping Machine tapping Machine tapping Hand tapping For metric thread For inch thread For pipe thread Classification of taps
Taps for tapping are turned by hand with a collar that is mounted on a square shank. They come in adjustable and non-adjustable.
When threading with taps, it is important to choose the correct drill diameter for the thread hole, which must be larger than the inside diameter of the thread as the material will be squeezed out during tapping.
If the hole is too large, the thread is incomplete and if it is too small or equal to the diameter of the thread, the metal will press on the teeth of the tap, which can cause the tap to break and the thread to be torn. The size of the hole for the threads is selected from tables or determined by the formula: D-drill = O-thread. RH where K-coefficient of 1-1,08; P- thread pitch.
Hand taps are standardized and made in a set of 3 pieces. rough, medium and finish. A rough one removes up to 60% of chips, a medium one removes up to 30% and a finishing one has a full profile To determine where a tap is, look at the shank where one, two or three circular dents or numbers will be. The thread size is also stamped on the shank.
After making the hole, clamp the headstock in a vise and insert the tap into a screwdriver. Pressing the screwdriver against the tap and the workpiece, they turn it until the tap runs several threads into the metal, then they take the screwdriver with both hands by the crank and rotate it by intercepting the hands every half-turn. Do not turn clockwise all the time, but half a turn to the right. cut, then half a turn to the left to allow the chip to break and to exit freely through the screw groove. After you have finished tapping, turn the screwdriver in the opposite direction, unscrew the tap, then run the entire thread again.
TAPPING THE MALE THREAD WITH DIES. Depending on the design, dies can be round, rolled and prismatic (sliding dies) 9FIG 25 Muravyov).
Circular dies (lerki) is a solid or cut ring with a thread on the inner surface and grooves, which are used for the formation of cutting edges and exit chips. Diameter of cut dies can be adjusted within small limits (0,1-0,25 mm) due to insufficient rigidity. This allows resizing after wear and prolongs service life of dies
When threading, round dies are fastened in a thread collarSliding dies consist of two halves (half dies). Each has a thread size and a number 1 or 2 for fastening to a special tool, a die. fig. 25 Ant. Thread cutter.page 41 Muravyev
Thread rolling dies, page 117 Makienko, are used for rolling precise thread profiles.
NOTE: If it is less than the required diameter, it must be set in accordance with the following instructions. that in the process of thread formation, the metal is pulled and the diameter of the rod is increased. A good thread quality is obtained when. if the core diameter is 0,3-0,4 mm smaller than the thread outer diameter. If it is less than required, the thread is incomplete and if it is more than required, the die cannot be screwed on the shank and the teeth could break because of overload.
When threading with taps, it is important to correctly select the diameter of the drill for the thread hole, which must be larger than the inside diameter of the thread, as materials will be squeezed out during threading. If the hole is too large, the thread will be incomplete, if too small or equal to the diameter of the thread then when you squeeze the metal it will press on the teeth of the tap, it could lead to a broken tap, the thread will get equal. The size of the hole for tapping is selected from tables or determined by shape: D-drill = D-thread. KP where K-coefficient of 1. 1.08, P. thread pitch.
After preparing the hole, workpiece is clamped in a vice, and a tap is inserted into a screwdriver. Pressing the screwdriver to the tap and the workpiece is rotated until the tap runs a few threads into the metal, then the screwdriver is taken by the handle with both hands and rotated with an interception of the hand every half-turn. Do not turn clockwise all the time, but half a turn to the right, half a turn to the left to allow the chips to break and could exit through the screw groove. Having finished tapping, the screwdriver is turned in the opposite direction, the tap is unscrewed, and then the whole thread is run again. Rules for threading with taps (internal threads)
When threading with a tap, the rod is clamped in a vice 20-25 mm longer than the length of the thread. Chamfers the top end of the rod to secure the plunge cut. Then a die fixed in the clincher is put on the rod and turned with slight pressure so that the die is inserted by 1-2 threads.
After that the oiled part of the rod is lubricated and the clip is rotated by two tugs (1-2 forward and half a turn backward) It is necessary to observe the perpendicularity of the die to the rod. After threading, the thread can be rethreaded. Control is carried out with the help of gauges. plugs.