1、a E Z c c .- C - *) O 2 c 8 z a n W U r a c C .- E (3 c .- -E c a 2 Z ; 3968 lolerancer for Single-start Hob. for Imoluto Spur Geur olerancen eingngiger Wllzfr; 1 ;v 1 o;er 1 ;ri o,v;rI ove; 1,6 2,s 62 10 16 25 40 to to to to to to to to to Al f 70 f100 f 50 BN = lead of gashes or tooth row LI = hob
2、 lead (helix) I The sign in the brackets is + if the gaah lead and the hob lead are in opposite directions, and - if they are in the same direction. I number of gashes or tooth rows DIN 3968 Peg8 5 Ueasured quantitj Hob lead in the direction of hand between any two cutting edges on the same thread B
3、ase pitch element measured from cutting edge to cutting edge + 4r- Base pitch within a contact region Test diagram Lcontact rcgionJ yabol ,aria- Ienoting Qualit3 class ion I A B C D - - - - Tolerances in pi (1m = 0.001 u) for modulem over 10 to 16 25 - over 16 to 25 32 - over 25 to 40 40 80 160 - -
4、- - 310 - ri Where : EN = lead of gashe8 or tooth rows E = hob lead (helix) i = number of gashes or tooth rows n = number of cutting edges over which the The sign in the bracket8 io + if the gash lead and the hob lead are in opposite directions, and - if they ara In the same direction. measurement i
5、8 made not defined I4 i4 I4 i5 &6 i8 i10 i12 f16 Where : te I base pitch i I number of gaehes or tooth rows 12 14 16 18 2025 32 40 5 25 132 36 40 50 63 80 100 50 56 63 n 801001255600 not defined Other relevant atandarde: For rundaientalterms and notation for hobo for Involute opur gear., 0.0 DIH 8ooO (at precent ppdergoiirg revision) Por dimeeeiorie for hobs for pur goara dth dutch drin .lot or L.pw, #eo DIB 8002 Por bores, keyways and driving features for tools with parallel bore, see DIN 138
