Chuck for Small Screws

Nothing looks more unsightly in a model than screw ends which, having been found to protrude too far after assembly, have been sawn off and either left in this condition, or roughly trimmed with a file. Quite apart from the matter of appearance, however, such screws are liable, when subsequently withdrawn, jo damage their tapped holes by the inevitable burrs which are bound to be left on the screw ends after sawing or filing. If again assembled in the same condition, it will be found difficult...

High Speed Turning Hint

When turning brass at high speeds, the small cuttings fly off the work with some force, and it is always a good plan to use an eye shield. Apart from protecting the eyes, there is another point to consider, and that is the small cuttings flying in all directions take a good deal of time in clearing up. In order to confine the cuttings in a small space on the lathe bed, the writer uses a shield, as shown at A, in the illustration. The shield is easily made from a piece of thin sheet metal, and...

Adjustable Wirebending Tool

The sketches show a useful tool which may be used for wire bending, straightening, or cutting. It is designed for use in a vice, and is of simple construction. It is made of steel throughout, shaped as shown, with a dovetail slot down the centre. It is made tee shaped for convenience of gripping in the jaws of a vice. Two pieces are made to fit, and slide, in the dovetail slot. The end of one is shaped to form a cutting edge, and the other end has two tapped holes to take a locking screw and a...

Boring and Facing Tools

Many operations on the lathe require special tools and cutters which model engineers and professional turners in small workshops must design and make themselves. Their position differs greatly from that of machinists in large works where everything is prepared by planning and production engineers. There the skill of lathe operators goes into their work opportunities for initiative are limited. It is different at home and in small commercial workshops. As many facilities are lacking, ingenuity...

Boring Recesses

It frequently happens that a recess, such as that indicated at a in the accompanying sketch, has to be cut in a bore, to a definite depth, by means of a tool b which is similar to a square-thread tool and is supported in a boring bar c. Gauging the depth of such a recess is usually difficult during machining, but the provision of a stop on the boring bar in the form of the screw d enables the recess to be cut accurately to the desired depth. The tool projects from the boring bar while the stop...

Collet Chucks

We illustrate here a chart giving the specification for various sizes of standard collets as employed on the best known types of precision lathes. This particular list was compiled by Mr. George Gentry from data supplied by the late Mr. George Adams, and was published in the issue of The Model Engineer dated November 29th, 1934, together with further particulars and general information on these chucks. A drawing of a lathe mandrel, showing standard type of draw tube, is also given here.

Compound trains

To make clear the principle of compounding, which will be necessary in some cases where the drivers given are not available, the interested reader must understand the idea of speeding down or up in proportion to the fraction or multiplier of 1 mm. required to be cut. If, for instance, mm. is required and no 20 wheel is available, the compounding wheels must have the ratio 2 to 1 down, say 48 and 24, thus retaining the original 40 driver, put it 40 driving into 48 on intermediate stud and 24...

Correcting machine tool inaccuracy

We are always up against the lathe that simply won't turn parallel, or circular, or true, according to the complaints of its operator. Parallel error is rarely, if ever, (A basic lathe of similar type and quality to an ML7 cost about 8.50 in the mid-1 930s-Ed.) completely eradicable from any but the very best precision lathes, because the ability of a lathe to perform rectilinear operations depends upon a copying principle, in which the templates or straightedges are its own slides. Any...

Curing the Incurable Chuck

Dear Sir, It may interest those of your readers who suffer from the incurable chuck of the three-jaw S.C. type, which is too far gone for grinding, etc., to know how I overcame my difficulty in that direction. I was employed at a firm of electrical engineers as toolmaker, and I had considerable spare time jobs of the repetition type to be done on our old Hack lathe (our own name for a bad lot), the chuck of which was hopeless for accurate work. I dismantled said chuck and thoroughly cleaned,...

Cutting Multithread Screws

Multi-thread screws can be easily cut on a lathe by the following method. A multi-thread screw consists of two elements the pitch of the thread and the number of separate threads in this pitch. Suppose we want to cut a double-threaded screw with a pitch of 1 12, then in every 1 12 there will be two separate threads, and in one inch of the screw there will be 24 threads. Set up the screw-cutting gear to cut 12 t.p.i. and put in the toolholder a chaser for 24t.p.i., and cut in the normal way....

Cutting the slot

This may be done by means of a hacksaw. The shank may be held in the jaws of a vice, or conveniently, especially with a very small screw, in a chuck, and the latter held in the vice. A difficulty is to start the slot, the saw tends to slip about sideways. With a fine three-cornered file, cut a starting groove as No. 1 5, in which to place the saw blade. As a guide, you might previously have scribed a diametrical line across the head, whilst the screw was in the lathe. A guide to register depth...

Damage from swarf

Again, where there is no limit (other than binding on the leadscrew) to the depth of engagement of the half-nuts, the depth of engagement could be more easily upset by the accidental entry of a bit of swarf B PARTIAL ENGAGEMENT NUT 'LACS' ACCORDING 10 DEPTH OP ENGAGEMENT B PARTIAL ENGAGEMENT NUT 'LACS' ACCORDING 10 DEPTH OP ENGAGEMENT Fig. 1 Diagram illustrating effect of imperfect or irregular engagement of half-nut s) with leadscrew of Acme form, and showing how a screwcutting operation could...

Divider for a Portass

Readers with a Portass or similar lathe may be interested in my divider, if they have a 60t bull wheel. The conical shape detent is, perhaps, not perfect but it works well enough. Slide in detachable piece slotted for teeth and drilled to receive conicol detent Slide in detachable piece slotted for teeth and drilled to receive conicol detent

Forming and Finishing a Screwthread

When V-threads of relatively coarse pitch are cut, the load on the tool point becomes very heavy, as the breadth of the cutting edge in action increases rapidly with the depth. Top rake, which in normal circumstances can be used to reduce loading in machining steel and other tough metals, has a limited value in screwcutting. Experienced turners sometimes ease the load on the tool by shifting it sideways slightly between cuts, using the topslide feed, and centralising it only for the final cuts....

Forms of screw head

The plain cheese head is shown by Nos. 6 and 8, rounded cheese head, No. 9 filleted, No. 10 round, No. 11 countersunk, Nos. 1 2 and 13, being formed and parted off. Grip the shank in a chuck, No. 8, and turn the head to the shape desired, before you cut the slot. The various shapes can be partly or completely formed as in No. 5, the complete parting off operation being withheld to allow this to be done. No. 14 shows a tommy head, it is drilled through to take a rod or tommy bar instead of being...

General requirements

The novice at setting up screwcutting trains must realise that in arranging a compound train, double-width intermediate studs are necessary, and a double-width nose on lead screw. Idle wheels may have any number of teeth. If the lead screw has a right-hand thread, the mandrel and lead screw must revolve in the same direction to cut a right-hand thread. Unless a cluster gear or other means of reversing the gear train are provided, therefore, one idler gear between mandrel and lead screw must be...

Hints on Filing

The choice of a file for a particular job is often looked upon with indifference by the amateur. But the idea that any file will do, is a wrong idea, and is sometimes very disastrous to economy. New files should always be kept for use upon brass or cast iron, as a blunt file has very little effect on these metals. In the case of cast iron, however, the outside surface or skin of the casting should first be removed by chipping, grinding, or some other process, before applying a good file, for...

In defence of the cheap lathe

The faults and limitations of the cheap lathe are always being brought forcibly to our notice, but it is only fair to say that in many cases they are very much exaggerated. One often hears that such and such a lathe cannot be used to bore a cylinder or turn a parallel shaft but it all depends on how much skill or intelligence the operator is prepared to use, and it is fairly safe to say that at the present time there is not a lathe on the market which is not capable of turning out excellent...

Introduction

When the far-sighted Percival Marshall founded The Model Engineer and Amateur Electrician in January 1898 it was, to paraphrase his words, in recognition of the army of workers whose tastes lay in the direction of mechanics and electricity having no journal devoted to the subjects from the amateur's point of view. At that time most people were more familiar with horses than machines and the internal combustion engine and electricity, which would in time supplant wind, water and steam as major...

Lathe Carrier

A few days ago I had to grip a piece of screwed rod in the lathe by means of a carrier, and found I had nothing suitable for the job. A carrier was soon made, in this way I scooped out a hollow in a piece of soft brick, the kind used by bricklayers for rubbed work, (but Plaster of Paris when hard and dry would do as well), and cast the lead jaws 1, and formed the hollows to grip the work with a coarse round file. Then I cut a short piece of steel, 2, and a longer piece, 3, and arranged two...

Lathe Toolposts

Barnes lathe has a T slot for the toolpost and after considerable use the projecting parts on which it clamps become badly worn and tend to be pulled through the tool supporting ring. In an endeavour to spread the load I made a T piece as per sketch and then turned off the end of toolpost as shown to -j in. dia. x - in. long and tapped a hole in the end in. BSF and made a screw to hold the parts together. This screw is done up tight with just enough clearance to allow the toolpost...

Overcoming the Deficiencies of Inaccurate Machine Tools

The old saying that a bad workman always finds fault with his tools, may contain a great deal of truth, but like most old sayings, is often abused by being turned inside out. In other words, it is definitely wrong to say that anyone who finds fault with his tools is a bad workman on the contrary, it is only by finding and fully recognising the faults in tools that one can ever hope to make the best use of them. There are faults in the very best of machine tools, as indeed, in any work of men's...

Packing

In loading or re-loading a four-tool turret, or in setting any tool to the correct centre height in a lathe (unless an adjustable height toolpost is being used), a search for packing pieces to put below the tool shanks can easily waste a good deal of time. We have our bits of hacksaw blade (giving a rather drastic increase in height), and pieces of brass strip, shim-stock and so on, but seldom any real plan. I long ago decided that something should be done, and now I always keep a small tray...

Query Knurling Troubles

Can you advise me, please about a trouble I encounter when knurling I am using a single-wheel knurling tool, and while I am fairly successful (but not always) in obtaining a plain straight or diagonal knurl, I am in trouble when attempting a double diagonal knurl that is, when using right- and left-handed knurling wheels in succession. The second wheel usually wipes out the first set of knurling completely, or so cuts it up that the appearance is destroyed. It would appear that you are applying...

Ratio of wheel numbers

If the pitch of a screw to be cut is given, the ratio of gearing required is expressed as the ratio of the pitch to be cut (on the mandrel end) to the pitch of the lead-screw (on its appropriate end). If, however, the reciprocal of the pitch be given (i.e. number of threads per inch), the reciprocal of the lead screw pitch is put on the mandrel, and the screw to be cut on the leadscrew. In the first case, as an example, if it is desired to cut a pitch of 1 mm. with a leadscrew of 2 mm., the...

Removable Nose for a Mandrel

A useful addition to a Myford ML7 lathe is a removable nose for the outer end of the mandrel. I found it quite simple to make. It consists of a nosepiece which is a replica of the standard mandrel nose, and an extending neck which is stepped. The in. dia. step passes through the hole in the gear guard and forms a stop at the end of the mandrel. The end of the smaller -jf in. dia. step is sawcut and coned out, and a mating cone is made. A in. dia. clearing hole is drilled right through the...

Screwcutting BA Threads

I trust that the reproduced chart (see overleaf) may be of interest to many of your readers. You will see that it gives screwcutting trains for B.A. threads from 0 to 12, and has been compiled especially for the M.L.7 lathe. It is, of course, applicable to any lathe with an 8 t.p.i. leadscrew provided that 21, 38 and 46 tooth wheels are available.

Screwing hard steel

For ordinary connection purposes, screws made from soft steel are usual and serve the purpose reasonably well. Occasionally you may require a screw to be hardened and tempered, as would be necessary if it is to serve as a pivot bearing, or as a set screw of more than ordinary quality. Soft steel may be case-hardened, but for best service, high grade steel is required. This may be the kind sold under the name of silver steel, or that generally known as cast tool steel. The latter is not the...

Screwing the shank

If a solid die is used, taper a portion of length as indicated by No. 2, this will assist the die to grip and start the thread. With a two-piece die, taper is not required, grip the die about midway along the shank and screw forward or backward as seems the easier, run the die along the whole length, giving a light preliminary cut. Do not crush in the die with the idea of screwing a full thread at one passing, take a series of light cuts along the entire length until a full thread is given. A...

Screwmaking between centres

The home mechanic, perhaps, does not possess a self-centring or other chuck suitable for holding a length of rod or the screw to be made is of too large diameter or too great a length for available chucking. It can be made between centres of the lathe. If several are required, they can be turned and screwed two at a time as indicated by Nos. 17 and 18, the former shows the roughing out stage, the latter the finished screws ready for being finally separated. By the same method, pins and other...

Second Operation Set Ups

A sound lathe-work principle is to machine as much as possible of a component at a single chucking in order to preserve alignment between faces and concentricity on diameters and to save time in resetting. Many chucks do not hold really truly, particularly after a period of use, and there are components whose slenderness or fragility renders their rechucking a problem. Often, of course, a second setup is inevitable and consideration must then be given to ensuring truth, avoiding distortion, and...

Setting Lathe to Turn Parallel

When turning a job between centres, it is necessary to test it with a micrometer at two positions a fair distance apart, to see if the lathe is turning parallel or not. This hint will save considerable time, and it should be used on every job of this nature, because when resetting the tailstock at different positions on the bed, it will be found that the lathe will not always cut dead parallel. Take a roughing cut along the centre of the job, as shown in sketch, leaving about in. each end light...

Simple Tool

The drawing shows a tool and holder I made and use frequently. The tool is simply a broken Slocombe drill ground to a radius to gel a smooth finish. It is very useful, and as it is high-speed tool-steel, it cuts almost anything. I hope it may interest other readers. secure the piece of M.S. by one hole, pointing towards chuck. Take out the screw from carrier and run a nut on it, now insert it from the back of M.S. strap in the other hole and screw on the carrier body lightly. Chuck one end of...

Tapers

The desirable true running of a pulley or flywheel taper-fitted on a shaft is generally best ensured by finishing faces and outside diameter with the component mounted on a mandrel running between centres in the lathe. All important surfaces are thus finished at one setting and the wheel is both parallel and concentric a condition difficult to achieve by chucking and re-chucking no matter how carefully this may be done. The preliminary roughing out is advisedly done in a chuck (which can be a...

The Art of Drilling Holes

To a beginner at mechanical work, drilling a hole may seem to be the easiest and simplest of workshop operations. Regarded merely as pushing a drill through a piece of material and thus producing some sort of a hole, it may be very easy to accomplish. But if the hole is to be circular, accurately to position, straight and in line of position, the operation requires accumulated skill, knowledge of the technics of drills and experience with materials and the kind of machine or other appliance...

The ubiquitous lathe

The lathe has been called the father of all machine tools. In the amateur's workshop, it is not only the father, but also the whole family, since it is called upon to deal with practically every kind of machining operation. It is, in fact, the backbone of the entire workshop equipment, and the wise amateur will obtain the best lathe that he can afford. Unfortunately, the great majority of people who indulge in mechanical craft for the love of it are by no means affluent, and their expenditure...

Tightening Adjusting Screws on Cross Slides of Small Lathes

It is frequently found that the adjusting gibs to the boring tables and cross slides of small, medium-priced lathes are difficult to keep pressed tightly, and yet freely, against the slides. The screws which hold them in place will loosen under the vibration of cutting. In my lathe, this had the effect of leaving minute ridges in the work, and of causing cylinder bores, etc., to come out tapered. The difficulty was overcome by taking out the adjusting screws, cleaning them carefully, and...

To remove apron and halfnuts

A note on this has been included for the benefit of those who may not be familiar with the easiest method, which is (1) Remove the leadscrew collar, change wheel and Woodruff key. (2) Remove the right-hand leadscrew bearing bracket from the lathe bed, and slide out the leadscrew to the right. (Put the leadscrew in a safe place, where it will not get damaged or dirty.) (3) Unscrew the three cap-head screws which go down through the top front of the lathe saddle, and the apron will be freed. (4)...

Turning the shank

The screw is made from a length of rod, iron, steel, brass, copper, zinc, aluminium, according to the material required. Clamp it in a chuck, leaving sufficient projecting to give the entire length of screw, including the head and a margin for cutting off by a parting tool. With chucked work, always have the minimum amount of projection, the farther away the cutting tool operates the more likely will be vibration and spring. A likely result is unevenness of surface and tapering in of the work...

Working Pipes and Tubes

The important thing to remember when working pipes and tubes is to avoid collapse and splitting. The various methods employed are governed by material, diameters, wall thickness, radii and angles of bends. When sawing thin-walled tubing, fine-pitch hacksaw blades are essential by holding the tube in the vice, inserting a close-fitting mandrel or rod and placing packing round the outside distortion can be prevented, as at A. Alternatively, soft clamps can be made from pieces of board, gripped...

X

Nexus House Boundary Way Hemel Hempstead Hertfordshire HP2 7ST England L0 O0 ecr CUGH OF EALING I LIBRARY & wrOfs ON SERVICE First published by Nexus Special Interests 1997 in this collection Nexus Special Interests 1997 ISBN 1-85486-145-X All rights reserved. No part of this publication may be reproduced in any form, by print, photography, microfilm or any other means without written permission from the publisher. Phototypesetting by The Studio, Exeter Printed...

Taper uniformity

When the shaft is available on which the wheel is to fit, it can be tried in the taper as this is machined (or reamed) in order to locate the wheel endwise correctly in which respect, should the taper bore be made slightly too large a reducing cut can always be taken over the face. sleeve can be fitted for a distance X to Alternatively, the bore can be sized obtain when the taper is at correct size from a reamer or mandrel, as at D, which in the case of a reamer, a sleeve is essen-may be...

Winding Small Springs

The following method of winding small springs may be of interest to readers. I have used it for a number of years after seeing a description in a handbook Kempe, I believe but it does not seem to be generally known. I. Tension springs. A piece of ebonite or fibre is held in the vice and two sets of holes are drilled. Those on the left serve to tension the wire which is threaded through alternately front and back those on the right act as bearings for nails or suitable size mandrels held in a...

Sets and joggles in small details

It is most difficult to set small details without distortion, especially those forming part of a locomotive valve-gear, due mainly to their relatively large cross section, compared to their length, and even when distortion is overcome, there is still the question of maintaining reasonable accuracy. The easiest way to overcome distortion and inaccuracy is to make a simple bending tool to use in the vice see Figs. 5, 6 and 7. The part to be set or joggled should be supported by a couple of pins...

Jigs for shackles eyes and chain links

Jig Cut Chain Links

The body of the shackle jig is a piece of plate as thick as the inside width of the shackle, with the edge radiused the same as the bottom of the U of the shackle. Three holes must then be drilled and reamered for the pins around which the rod will be bent. Pins A and B must not stand proud of the body more than one diameter of the rod being bent, C must project at least two diameters. As an added refinement to avoid flattening, A and B, but not C, can be formed rollers, held by a pin. Pin C...

Cutting Square Threads

In the cutting of square threads the front cutting edge of the tool must be at right angles to the helix of the thread, and the tool itself can resemble a parting tool as the width of the blade should narrow slightly where it joins the stock, to provide clearance. You must add about 0.003 in. to the width of the cutting edge so that the tool can move between the flanks of the thread when you are finally gauging the work. It is also essential that the top rake should be correct in relation to...

Turning and Boring Phosphor Bronze

It is usually advised to have no top rake on tools, although I prefer just a very little myself. Take the first cut deep enough to get well under the skin, run slow, with the back gear in if necessary this will be desirable if cast steel tools are used. Do not use too fine a feed for roughing. When skin is removed inside and out, speed up the lathe, but phosphor bronze cannot be cut at the same high speed as brass. Grind twist drills as per sketch for cutting brass and phosphor bronze, but only...

Clasp Nut Engagement Stop

Whilst I cannot speak for all M.L.7 lathes, I found that mine, at least, suffered from the fault of being without a definite stop to determine the degree of engagement of the half-nuts with the leadscrew, it being found that when the lever was depressed to effect engagement, there was nothing to prevent the half-nuts gripping the screw with such force that a very considerable torque was required to effect the rotation of the leadscrew it was found almost impossible to move it when attempting to...

Winding Helical Springs

By means of the device shown in the sketch, open or close wound springs can be made with a minimum amount of trouble and danger in the ordinary lathe. The correct diameter of the mandrel A can only be obtained by trial one made seven-eighths of the inside diameter of the required spring is generally about right. The device consists of the shank E which is held in the tool-post of the lathe. The front portion is cut away to rest against the mandrel A the wire being kept taut by passing it...

Lathe Centre Gauge and Scriber

This very useful tool can be easily made, and serves the purpose of a gauge for setting the tool at centre height on the slide rest, also in lieu of a scribing block on the lathe bed, and, having a larger base, is better for marking out and setting work true in the chuck. For marking graduations in dividing work in the lathe it is far quicker and better than a screw-cutting tool clamped on the top slide on its side. The marking point can be swivelled and set to mark either a face or edge and...

A simple remedy

With a view to obviating this unpleasant set of potential trouble-making circumstances, and to introduce a measure of reliable consistency to the operation of screw-cutting, it was decided that some sort of depth engagement stop must be fitted to the half-nut mechanism and, after removing the lathe apron and giving the matter a couple of hours consideration, the following method was adopted as being the simplest solution, and one which would not spoil the external appearance of the apron. Fig....

Query Form Tool of Complicated Shape

I wish to make a form tool, for use on the lathe, to the shape shown in the accompanying sketch. The exact radius of the portion marked (X) is not important, but I wish the vees to be clean and sharply pointed. My difficulty is that I do not see how I am to grind these vees on an ordinary bench grinder, which is all the grinding equipment that I have. Your help and suggestions would be much appreciated. Form tools of complicated shape, such as you require, cannot be ground accurately on an...

Boring Bar Attachment

One of the tools we have to use on the lathe is the boring bar, and when it comes to cutting a slot in the bar and fitting cutters for various jobs, the time and labour becomes a consideration. Convenient way of mounting light cutters on boring bars. The attachment I am describing was designed for facing the sides of the crankshaft bearings in the main castings of small power gas engines, and the type of cutter used has done me a good turn on lots of jobs. I have used a cutter of this sort (see...

How to Plane Small Gears

Although small gears can be bought in many sizes, they must sometimes be made at home because a standard one is not right in size, in number of teeth or in material. You may need a steel gear instead of a standard one of brass or a gear which is to hand may have too few or too many teeth to give the required ratio. And there is the satisfaction which comes of making all the parts of a model or mechanism yourself. Providing that the gears are of fine pitch, planing with a form tool in the lathe...

Contents

SECTION 1 Lathes and Lathework 3 Forming and Finishing a Screwthread 10 Lathe Centre Gauge and Scriber 17 Sensitive Drilling Attachment 18 A Simple Lead Screw Chip Guard 26 Setting Lathe to Turn Parallel 30 A Centre-spacing Punching Tool 32 Turning and Boring Phosphor Bronze 33 Query Form Tool of Complicated Shape 34 Curing the Incurable Chuck 34 Tightening Adjusting Screws on Cross Slides of Small Lathes 35 Overcoming the Deficiencies of Inaccuratc Machine Tools 37 Small Bends, Sets and...

File Cleaning

We are often recommended to clean a file by rubbing it across the teeth with the end of a piece of brass strip brass presumably being specified as the least likely material to cause a premature blunting. This is strange, when you consider that files are made to cut steel, including carbon tool steels, some of which are quite hard even in the annealed state silver steel, for example. I have a very fine (and favourite) file in constant use for finishing diameters such as may be required to very...

Final adjustment

After fitting the stop and re-assembling, it is a simple matter to make the final adjustment. When the half-nuts are open, the stop adjusting screw is readily accessible at the base of the apron, and should be slackened off until the half-nuts grip the leadscrew, whereupon, by getting the feel by hand twiddling a change gear mounted on the leadscrew in the orthodox position, the stop adjusting-screw should be screwed up by small increments and the half-nuts operated until the lead-screw is free...

Twisted Rods

Sir, With reference to your problem of twisted brass rods. I have recently completed a Fowler Big Lion and the method I employed was as follows - Square brass tube was cut to 1 in. plus, annealed and filled with lead, a bush with a square hole was fitted in the chuck and another in the tailstock. The brass was then placed in the holes and the chuck pulled round the required number of turns, after which the lead was melted out. Incidentally I worked at Savages, King's Lynn, for a brief period....

Simple Lead Screw Chip Guard

Zyto lathe, I decided to make a lead screw chip guard, as there was not one fitted. I obtained a piece of steel gas pipe about 4-ins. long, internal diameter a little larger than the diameter of lead screw, sawed it down in half lengthwise, and then riveted a piece of steel strip on to it, bent at right angles. I next screwed the end of the strip to the lathe saddle and adjusted the guard so that it just travelled above the lead screw. This fitting is well worth making,...

Small Bends Sets and Joggles

The appearance of a model, or indeed any example of engineering work, is much enhanced if all the minor parts show evidence of neat and careful workmanship. Such bent components as shackles, eyes, and chain links in bright mild-steel present certain difficulties in this respect, but it is possible to produce them in such a way as to avoid spoiling the original finish with hammer marks, bruises and burrs. If one has considerable dexterity with round-nosed pliers, and the work is small enough in...

Cutting Metric Threads

The use of a 127-toothed wheel for metric screwcutting on an English lathe By Geo. Gentry July 1955 This article relates to a problem which is constantly recurring in both amateur and professional workshops, and it is proposed to deal with it in some detail to satisfy the requirements of querists who have asked for advice on how to produce metric threads on lathes with fractional-inch pitch lead screws. In the particular instances, the pitch of the lead screw is not specified, but it will be...

Making Screws

It may seem that notes about this subject are superfluous now that screws are produced and sold at small cost and in almost any size and shape for general mechanical construction. The kind I am implying are those used for connecting parts together, round head, cheese head, countersunk patterns of screw, threaded along the whole or part of the length of the shank. They are made in quantity, as bolts, nuts, keys, pulleys, line shafting and other general engineering supplies are produced...

Centre Spacing Punching Tool

Bradbury Winter May 1927 It often happens that a series of holes are required in a circle, either on the face of a job or on the outside edge. To make a circular scratch and cross scratches and centre punch the points of intersection is inaccurate and slow. For such jobs I have a piece of J- -in. square steel, about 4 ins. long, with a hole, about No. 45, near one end, and in this hole a piece of steel wire in. long Small centre punch mounted for use in the lathe. is a good sliding fit....