Page 17 - Threading_Handbook

Possible Combinations of Thread Tolerances:
Pich Minor
undersized Diameter Diameter 8 8
Diameter Diameter
Minor
Pich

Internal 8 8 7 7 INTRODUCTION
(Nut)
Threads 7 7 G 6 6
H 6 6 5 5
more precise 5 5 4 4

Basic Size 4 4
3 4

4 6

3 4 5 8
more precise 3 4 4 6 h 6 - -

8
7
5
External
(Screw) 4 6 g 6 - 8 -
Threads
3 4 5 8 7 - 9 -
Pich Major
4 6 f 6 - 8 -
Diameter Diameter
-
5 8 7 - Pich Major
9
undersized e 6 - - 8 - Diameter Diameter

9
7
-
8 - Pich Major
Diameter Diameter
9 -

Pich Major
Diameter Diameter

Thread accuracy can be classified by three classes: fine, medium, and coarse, depending
on the length of thread engagement (the length of interaction between the fastener and nut
member (i.e. nut or mating material for the screw) which is divided into three groups: short,
normal, and long.

LE

LE

LE - length of thread engagement 17