Page 710 - Master Catalog 2017, Inch

Technical Information
Common Thread Forms

ISO M (Metric) and UN (Unifi ed National) UNJ (controlled root radius) Whitworth (BSW)

Use: Fittings and pipe couplings for gas, water, and
Use: All branches of mechanical industry. Use: Aircraft and space industry. sewer lines (replaced by ISO).

American Buttress NPT (American National Pipe Thread) BSPT (British Standard Pipe Thread)

1/2 D play

1/2 D2 play axis of screw taper 1:16 taper 1:16
1/2 D1 play axis of screw

Use: Fittings and pipe couplings. Use: Fittings and pipe couplings. Use: Pipe thread for steam, gas, and water lines.
TR DIN 103 Acme Acme, truncated (Stub)

nut
1/2 D play
1/2 D play

1/2 D1 play 1/2 D2 play
screw 1/2 D1 play 1/2 D2 play
A = 0,0307 P
B = 0,3707 P—x D play A = 0,4224 P
C = 0,3707 P—(D1 play—D2 play) B = 0,4224 P—x D play
Use: Mechanical industry for motion Use: Acme-General is used in mechanical industry for C = 0,4224 P—(D1 play—D2 play)
transmission screws. motion transmission screws. Use: Where normal Acme is too deep.
API Casing and Tubing Round Thread Form

pitch
line

taper = 3/4" per foot (62,5mm per meter) on diameter

NOTE: Taper shown exaggerated.

F84 widia.com

F084 F085 Mi
WID M
i
V
16 T
di
Th
i
L WID_Master16_Turning_Threading_F084_F085_Minch_REBRAND.indd 84 h REBRAND N b 9 2015 4 02 PM 11/12/15 4:31 PM