Общий каталог Yamawa 2022 - 2023 - страница 987

Flowchart : M8 tapping
PD PD
Boring before tapping


Engagement ratio on cutting taps
Check 1


Engagement ratio on roll taps
Min


Internal threads
Min 100%
100%
Max 80.4%


Internal threads
M2


Internal threads
Ta
ps


M3
Min Max Ta
ps
Max
Length of
engagement=12.1mm 80.4%
74.1%
【Length of engagement】
On "middle" engagement class, 7H class can be chosen Internal threads made by roll taps are M4
in case of "L" engagement length. different from those made by cutting Ta
Internal threads
taps on the shape of minor dimameter. ps
Engagement Unit : mm
Symbol


Middle
Coarse


classification Engagement Unit : mm
D1
d=8.0mm
Fine


Engagement length External threads
Drill size Min
*Hole size for thread forming taps
length classification
(ref.) Max M5
S Short engagement length 4H 5H − S≦4（mm） Min Max Ta
M Normal engagement length 5H 6H 7H 4＜M≦12（mm）
Bored hole size 6.8 6.647 6.912
7.36 7.49
ps

L Long engagement length 6H 7H 8H 12＜L（mm）
Engagement ratio 88.7% 100% 80.4% Forming condition changes depending
on workpiece's Material and shape.
P=1.25mm D1 is minor diameter of JIS 6H(2nd Class) of internal threads Above is for customer's reference.
M6
Ta
ps

Tolerance area of tap's pitch diameter 【Thread class of cutting taps】
M8
Class PD tolerance Ta
ps
【Pitch diameter】
P2 20μｍ〜40μｍ
Diameter of imaginary cylinder or cone Internal
internal threads
P3 40μｍ〜60μｍ
Check 2


which makes equal the width of threads
and width of space between the threads M1
0
P4 60μｍ〜80μｍ Ta
ps
P2
P3 P5 80μｍ〜100μｍ
P4 *Above shows the plus tolerance M1
Width of P5 by setting PD basic size as "0". Ta 2
ps
threads 【Thread class of roll taps】
Width of space
Class PD tolerance M1
between threads Ta -M
G7 76μｍ〜89μｍ ps 8.5
Pitch
Threading


diameter G8 89μｍ〜102μｍ
G7 M9
G8 *Above shows the plus tolerance
by setting PD basic size as "0". Ta -M
ps 24

Basic size of pitch diameter
-200μm -150μm -100μm -50μm 7.188mm +50μm +100μm +150μm +200μm
M2
Ta 5-M
ps 48

Ⅱ G7 G8
P1
M5
Ta 0-M1
P2 P3 P4 P5 ps 00
Tolerance of dies is the P2
target of external threads
Fo
Class of dies 6g external threads(-146〜-28) 6H internal threads(0〜160) rU
thr nifie
e
NR GR GP NP Ta ads d
Ⅱ Solid dies ps
P1 Solid dies JIS 2Class external threads(-150〜-40) JIS 2Class intenal threads(0〜130) For
P2 for Auto Lathe WR GR GP WP
W
thr hitwo
e r
Ta ads th
ps
Relative position of PD tolerance area of external threads, internal threads, taps and gages.
For S
crew
on se threads
w us
Ta ing machi ed
(–) ← Basic size of pitch diameter → (+) ps（ nes
M）S
7.188mm
Unit : μm Unit : μm For
P
Ta ipe th
Ring gage pitch diameter(for external threads inspection) Plug gage pitch diameter(for internal threads inspection) ps read
s
Check 3


NR6g -160 〜-146 GR6g -37〜-23 GP6H 7 〜 17 NP6H 160 〜 170
For
WRⅡ -150 〜-142 GRⅡ -52 〜-44 GPⅡ 4 〜 12 WPⅡ 122 〜 130 A
pip meric
Gage check


e a
Ta thre n
NR : NOT GO ring gage GR : GO ring gage GP : GO plug gage NP : NOT GO plug gage ps ads
WR : NOT GO working ring gage WP : NOT GO working plug gage
For
Unit : mm Unit : mm M
thr iniatu
e
Accuracy of external threads Accuracy of internal threads Ta ads re
ps
Major diameter Pitch diameter Minor diameter Major diameter Pitch diameter Minor diameter
6g 7.760〜7.972 7.042〜7.160 − 6H − 7.188〜7.348 6.647〜6.912
JIS 2class 7.790〜7.960 7.038〜7.148 〜6.427 JIS 2class − 7.188〜7.318 6.647〜6.912


Sizes-23