ISO 2X

ISO 1 ISO 2 ISO 3 ISO 1

ISO 2 ISO 2X ISO 3

ISO 1 ISO 2 ISO 3

ISO 2X ISO 2X Internal threads 5H

ISO 1 ISO 2 ISO 3 Internal threads 6H

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

ISO 2X

ISO 1 ISO 2 ISO 3

About UNJ Threads

UNJ Threads are Unified Threads used for Aircrafts.

<Features of UNJ Threads>

In order to protect the breakage from thread bottom of external threads, UNJ thread defines the minor diameter larger than Unified thread and the range of root bottom R. And accuracy of threads is only defined in highest classes of unified threads, 3A of external threads and 3B of internal threads. UNJ Threads were initially defined as a MIL Standard (American Millitary Standard ). It is now superseded by American SAE Standard ( Automobile Engineers Association). Standard Numbers are as follows:

SAE AS8879D Screw Threads - UNJ Profile, Inch

Controlled Radius Root with Increased Minor Diameter

<Basic Profile of UNJ Thread>

Basic profile of UNJ thread is shown in the drawing below. Truncation on thread root of external threads is 5H/16, that is, H/16 larger than H/4 of normal Unified Thread's truncation. And radius of thread root is 0.18042P~0.15011P.

Basic Profile of UNJ Thread

Internal Threads

30° 30°

60°

External Threads

P

H=0.866025PD =d【reference】
HD=d
1 =9H/16229H/16 =0.487139P
d2 =d-0.649519PD1 =d1H/2 (8H/16)=0.433013P
d1 =d-0.974278PP =25.4/n5H/16 =0.270633P

n =Threads per inch

H/8 (2H/16)=0.108253P

<Bored hole size>

Bored hole size is recommended to be a little larger than that for

normal unified threads considering that the minor diameter of UNJ

series is larger than that of normal Unified Threads. unit: mm Minor Diameter Size Bored Hole Size Maximum Minimum

No.6- 32 UNJC2.9382.7342.89
No.6- 40 UNJF3.0532.8883.01
No.8- 32 UNJC3.5993.3943.55
No.8- 36 UNJF3.6623.4803.62
No.10 - 24 UNJC4.0643.7954.00
No.10 - 32 UNJF4.2544.0544.20
No.12 - 24 UNJC4.7044.4564.64
No.12 - 28 UNJF4.8154.6034.76
1/4 - 20 UNJC5.3875.1145.32
1/4 - 28 UNJF5.6615.4675.61
5/16 - 18 UNJC6.8326.5646.76
5/16 - 24 UNJF7.1096.9077.06
3/8 - 16 UNJC8.2557.9798.19
3/8 - 24 UNJF8.6798.4948.63
7/16 - 14 UNJC9.6399.3489.57
7/16 - 20 UNJF10.0839.87610.03
1/2 - 13 UNJC11.09410.79811.02
1/2 - 20 UNJF11.66111.46411.61