1 ~ R Ii: COM M Ii: N D Ii: D LA T H Ii: P RAe T ~. C Ii: - ( © 0 1m t d . ) ..2' ..2 , ~ t..' L' h h X T xL. h .. lameter an .. lengtn or WOb. 1S ' mc es, t en = ---me es 24 or To find the amount of off-set X, if the taper is T mm. per metre TxL mm. on diameter and length of work is L mm., then X 2,000 TABI..IE 1 Cutting Angies foe" 1-1.5.5. and Cemented Cae"bkie Tool$ Materials H.S.S. Cemented Carbide Top Rake Clearance Top Rake Clearance Mild steel 20° 6° go 4°-f>° High carbon steei 10° 4° 3°-4 0 4°-6 Q Soft cast iron 10° go "c-S0 4°-f>° Chilled iron .. , ao 4° (;0 2°-4° Copper '12° 1Co 13° 4°-6 0 Brass .
., 0°-6 0 i 0° 3° 4°-6 0 Aluminium 30° 10° i&~ 6 c -s 0 lfthe induded angle oftaperis e, X = L x tan~ inches (mm.). 2 (3) If the lathe is fitted with a taper turning attachment, fig. 3, then more accurate tapers, either external or internal, can be produced than by the two preceding methods. By the use of this attachment, the lathe centres are not of course taken out of alignment, so that the bearing surfaces are unaffected. TAla:"'!: 2 Cutt~ng Speeds In feet per- m[;rЈ~~t~ (mffZtlres pe~ n'~r~~) Materiai H.S.S, Teols Cemer:ted Carbide Roughing :-in1shing Roughing Fini:hing fl:. roo ft. m. ft. m. ft. rn.
LATHE TOOLS In mounting turning tools in the rest, the tool should only ~xtend the minimum amount from the rest to obtain the maximum support against the downward pressure of the cut. For damping 'the tool, ample pressure is provided wit.'iJ. the spanner supplied, ane' on no Mild Steel '130 40 200 61 200 61 300 91 High carbon steel 45 14 60 18 200 6-, 400 122 Soft Ca'it iron 60 18 75 23 200 6'; 350 107 Chilied iron ... '10 3 15 4-5 is 4·5 30 9 Copper 200 6~ 200 6~ 4')0 122 700 213 Brass .. _ 250 76 400 122 400 122 700 213 Aluminium 300 91 .jDa 122 500 ~ 52 ,000 3051 TABLE 3 ;Feeds in Enches per freҐotut~on (mm. per- revoh.rdon) TOP RAKE ANGLE --! Material N.S.S.
and Cemen.ted Caib~de Too:s Roughing Fi:lishing lncnes mm. inches mm. ,i \, \ ! ,. rI ~\ ~, J j Mild steel .(rlO ·254 -007 ·178 High carbo?: St:;t; 010 ·254 ·007 ·i78 Soft cast !r'on ·013 ·330 008 ·203 Chilied :ror, -003 ·203 ·005 ·127 COPDer -020 -508 -OOB ·203 B~~ ... .~.~ ·~m Aluminium ·0'13 ·330 -007 ·178 FRONT CLE..A,RANCE ANGLE 18