Workshop and Production Section AIRCRAFT ENGINEERING April, 1943 Copies of the following Specifications may be obtained Th e specification deals with the dimensions for begin. On the grounds of expediency under at the prices indicated, from the British Standards th e noses of grinding machines, including plain presen t conditions the main portion of the work Institution, 28 Victoria Street, London, S.W.1. grinding machines with live spindles. I t provides will be issued in 8 parts , as follows : for two types of spindle nose—screwed and flanged. Par t 1, Section, 1, General Terms. Th e ilanged spindle noses have been based on the B.S . 4. V.2.—Casein Glue for Aircraft. The revi Par t 2, Section, 2, Machines and transformers. American Standard for Lathe Spindle Noses but sion of this specification became necessary owing to Par t 3, Section 3, Switchgear, and Section 4, a parallel register has been adopted in place of the th e difficulty in obtaining walnut test slips which Instruments . tape r register in the American Specification. The were specified for carrying out the strength test. Par t 4, Section 5, Transmission and distribu flanged type of nose has been adopted down to the As a result of research work which was carried tion. smallest size which will permit of the front fixing ou t by the Forest Products Research Laboratory Par t 5, Section 6, Electrochemistry, and chucks . Below this size screwed spindle noses have i t was found that beech slips could be used as an Section 7, Traction. been adopted. Price 2s., pos t free. alternative . The details of th e tes t hav e been modi Par t 6, Section 8, Lighting and Heating. fied and the design of a suggested apparatus for Par t 7, Section 9, Surge and Lightning Pheno assembling th e pieces for test is also included. B.S. 205.—British Standard Electrical Glossary. mena , and Section 10, Electri c Lifts, Electric Price : 1s. Part I. Welding, X-Ray s and Electromedical terms. A t the outbreak of war a revision of the B.S. Par t 8, Alphabetical Index to all th e sections. Glossary of Terms used in Electrical Engineering B.S.Sta. 2.—Services Specification for Steel Bars Eac h part will be published at 2s. Part s 1, 2, 3 ha d already been started, partly in connexion with for Hardened and Tempered Coil Springs. an d 4 are now ready; the other parts will follow at preparation s by the British Standards Institution Thi s specification gives four types of steel which shor t intervals. for the drafting of proposals for the revision of the ma y be used for hardened and tempered coil springs Term s relatin g t o Telecommunication, which were Internationa l Vocabulary published by the Inter for guns and armoured fighting vehicles, etc., and given in Sections 9 an d 10 of th e 1936 Editio n of the nationa l Electrotechnical Commission. As the war in each case the chemical composition is laid down. Glossary will be issued separately in due course progressed, it was realized that international co Attentio n is drawn to the fact tha t two out of the a s a revision of B.S. 204. operation would be impossible for some time to four types may only be used with the sanction of come, and work on the I.E.C. Vocabulary was th e Iron and Steel Control. For general engineering temporaril y suspended. I t was, however, felt that B.S. 1005.—Sampling and Analysis of High Purity purposes , steels composed of plain carbon or silicon th e revision of the British Standard Glossary Zinc and Zinc and Alloys for Die-casting. manganese are recommended. should proceed, particularly as it was by this time This specification was authorized by the Non- Requirement s are included with regard to the ou t of print and the type had been lost by enemy Ferrous Metallurgy Committee in 1941 in response manufactur e of the steel, and the usual clauses are action . There was also evidence of an increased t o a request received from the Zinc Development given covering testing, tolerances and marking. deman d for an .authoritative manual of electrical Association. The Standard sets out the methods of An Appendix covering the manufacture of nomenclature , in view of the considerable advances sampling an d analysis to be adopte d for th e examin hardene d and tempered coil springs from material now being made in certain branches of electrical atio n of High Purity Zinc and Zinc Alloys for Die- conforming t o this specification is issued separately. work and the increasing number of persons now casting covered by B.S. 1003 and 1004. It should Pric e 6d. engaged in activities in these directions. The pro be clearly understood that these umpire methods gress of the revision has necessarily been somewhat need not necessarily be adopted for routine control B.S. 1089.—Standard Workhead Spindles for Grind slow, as all the experts co-operating in the work in the production of the zinc or the alloys. The ing Machines. hav e been fully engaged on war work, bu t with the procedure set out is tha t t o be adopted in th e case of Thi s Standard has been prepared at the request activ e support of the Electrical Research Associa disput e requiring submission to an independent, of the Institution of Production Engineers and tion , it has now been found possible t o reach a stage authority . forms one of the series of British Standards for where publication of the revision in sections can Price 2s (2s. 3d. post free). machine tool details and accessories. acetylen e and oxygen are used. This flame adjust Applications for exemption licences must clearly The Butt Welding of High Speed Steel men t is easily mastered by anyone who can use a stat e the type, diameters and lengths, as well as T o assist toolmakers and other users of High torc h properly and once th e flame is correctly set it th e numbers required. Speed Steel in complying with S.R. & O. 1942 No. will no t blow back as does the acetylene flame and 760, which is th e Cutting Tools No. 2 Order, cover a narrow clean cut is effected. On this score then Substitution of Acetylene by Propane ing th e production of high speed steel tools by butt propan e is a better cutting medium than acetylene. welding, etc.,'a list of Standard Blanks has been Coal gas can be used for cutting and for certain or Coal Gas draw n up by the Machine Tool Control and will non-ferrous welding. The amount required even if Th e following notes have been issued by the shortl y be th e subject of a British Standard Speci substitutio n were carried to the limit is very small Ministry of Supply: fication, The accumulated experience of the steel compared with the demands for other purposes. I t is necessary t o economize in the usage of cal maker s and tool manufacturers has been pooled in Th e gas may be used direct from the mains for cium carbide for both shipping reasons and on compiling this list. machine cutting or with its pressure boosted for accoun t of new wa r demands . Supplies will b e main han d cutting. Better results may be obtained if Th e stand,ard blanks, consisting of a suitable taine d to essential consumers who are unable to th e coal gas is enriched with some other gas such as lengt h of high speed steel butt-welded to a medium effect any substitution. This maintenance, how propane , methane, ether or acetylene. As coal carbo n steel shank, will be kept in stock and will be ever, depends in some measur e upon reducing con ga s is piped round the works its use also economizes supplied in th e fully annealed condition ready for sumptio n in other directions. cylinders. machining . They will be suitable for the manu I n metal cutting and non-ferrous welding, the facture of twist drills, reamers, end mills, slot drills, actua l welding medium may be one of several gases "T " slot cutters, and machine taps, and square of which acetylene is the most commonly used. sections will be available for lathe and planer tools. Temperature Indicating Crayons Propan e or boosted coal gas can and should be used Th e Controller of Jigs, Tools and Gauges has in place of acetylene wherever this is technically In December, 1941 (see AIRCRAFT ENGINEERING, agreed t o exemp t th e following tools from th e provi possible; thus saving many thousands of tons of Vol. XIII, p. 356) mention was made of the sion of th e Cutting Tools No . 2 orde r :— importe d carbide. "Thermindex " temperature-indicating paints put Jobber s drills ; straight shank end mills ; On the ferrous welding side, when new plant is on th e market by J . M. Steel & Co, Ltd. , of Kern Tape r pin reamers ; straight shank slot drills ; installed, this should be for electric welding in House, 36-38 Kingsway, London, W.C.2. an d woodruff cutters. preference t o gas plan t while muc h light gauge weld Th e same firm now announces " Tempilstiks "— All th e above in th e sizes prescribed in th e British ing work now done by acetylene could frequently hea t sensitive compounds in crayon which melt at Standar d Specification may be made in solid high b e as well done by arc. specific temperatures and, in the " black range " of speed steel, if application is made t o th e Machine Propan e is a by-product of petroleum refining. temperature s particularly, provide a simple means Tool Control, 35 Old Queen Street, S.W.I, for an Sufficient supplies are available to meet all the of observing whether certain temperatures exist or exemptio n licence. purposes for which it could be substituted. . Thes e hav e previously been attained. Two methods of Long term exemption licences are also, being purposes cover all those for which acetylene is use are recommended : grante d b y Machine Tool Control t o cover th e manu normally used except th e welding of iron and steel. (a) Make a clear mark upon the surface, which facture from solid high speed steel of taps up to One 56 lb. cylinder of propane can do the same 1J inches diameter, where the cutting portion will melt and for all practical purposes dis amoun t of work as thre e 200 cubic feet cylinders of exceeds 40 per cent of the total length and the appea r when the temperature stated on the dissolved acetylene. Propane therefore economizes overall length is no t more tha n 7 J times th e diam crayon is attained. bot h steel and man-hours in the manufacture of eter . (b) Draw the crayon lightly across the surface cylinders. The cost and efficiency of both propane I t cannot be too strongly emphasized that the unti l a liquid smear remains. an d coal gas compare favourably with that of provisions of the Cutting Tools No. 2 Order apply Th e first method may be used when the object is acetylene . t o tools produced from all type s of high speed steel, indirectly heated, while the second is applicable to Ther e is always a prejudice against making including th e new tungste n molybdenum high speed temperatur e determination where a naked flame changes, and there appear to be some unfounded steel as well as th e high tungsten steels chiefly used is being applied directly to th e surface under test. objections in th e minds of those who have not tried in the past, and any firm requiring to make tools "Tempilstiks " are available to indicate the thi s comparatively new cutting medium. It is, for governed by the Order in solid high speed steel, following Fahrenheit temperatures :— instance, suggested that propane takes longer to eithe r on account of the absence of butt-welding hea t the metal up to the required temperature. 125, 150, 175, 200, 225, 250, 275, 300, facilities, or owing to the unsuitability of the tool Thi s is a fallacy, although th e flame does require a 350, 400, 450, 500, 550, 600, 650, 700. concerned for butt-welding, must obtain from the more critical mixture of gas and oxygen and the The y have a mean accuracy within 1 per cent of Machine Tool Control an exemption licence before limits of adjustment are finer than when dissolved th e stated melting point. proceeding.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Apr 1, 1943