Threads and Threading - Sportpilot.info

1872 HOSE COUPLING SCREW THREADS
Hose Coupling Screw Threads
ANSI Standard Hose Coupling Screw Threads.—Threads for hose couplings, valves,
and all other fittings used in direct connection with hose intended for domestic, industrial,
and general service in sizes 1 ⁄ 2 , 5 ⁄ 8 , 3 ⁄ 4 , 1, 1 1 ⁄ 4 , 1 1 ⁄ 2 , 2, 2 1 ⁄ 2 , 3, 3 1 ⁄ 2 , and 4 inches are covered by
American National Standard ANSI/ASME B1.20.7-1991 These threads are designated as
follows:
NH — Standard hose coupling threads of full form as produced by cutting or rolling.
NHR — Standard hose coupling threads for garden hose applications where the design
utilizes thin walled material which is formed to the desired thread.
NPSH — Standard straight hose coupling thread series in sizes 1 ⁄ 2 to 4 inches for joining
to American National Standard taper pipe threads using a gasket to seal the joint.
Thread dimensions are given in Table 1 and thread lengths in Table 2.
MAX
WITH WORN TOOL
MIN
MAJOR DIAM. OF INTERNAL THREAD
BASIC MAJOR DIAM., D.
PERMISSIBLE PROFILE WITH WORN TOOL
MAX
MAJOR DIAM. EXTERNAL THREAD
EXTERNAL THREAD
(NIPPLE)
MIN
p
24
MAX
MIN
PITCH DIAM. OF INTERNAL THREAD
p = PITCH
h = BASIC THREAD HEIGHT
= 0.649519p
f = BASIC TRUNCATION
=
1
h = 0.108253p
6
Machinery's Handbook 27th Edition
BASIC PITCH DIAMETER
MAX
MIN
PITCH DIAM. OF EXTERNAL THREAD
h
18
p
8
MINOR DIAM. INTERNAL THREAD
h
6
MAX
MIN
f
MINOR DIAM. EXTERNAL THREAD MAX
MIN
p
INTERNAL THREAD
(COUPLING SWIVEL)
1
2
allowance
(external thread only)
60˚
30˚
Fig. 1. Thread Form for ANSI Standard Hose Coupling Threads, NPSH, NH,
and NHR. Heavy Line Shows Basic Size.
p
24
p
8
h
18
h
2
90˚
h
BASIC MINOR DIAM.
AXIS OF SCREW THREAD
Copyright 2004, Industrial Press, Inc., New York, NY