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Dixon Sanitary 2016
800.789.1718
Technical
X
Thread Dimensions
* Dimensions given do not allow for
variations in tapping or threading.
DIN knuckle threads for sanitary applications have a unique
round shape making them easy to identify. There is a 30°
included angle between the threads. There are 6 to 8 threads
per inch for sanitary fittings. Measuring the ID of the round
nut or the OD of the threads on the weld liner will help with
identification. As Dixon Sanitary will be offering inch sizes, the
best size identification is the OD of the tube.
The threads for RJT fittings are British Standard Whitworth.
These look similar to straight threads but have a 55° angle and
small radii on the tips rather than the flat tips and 60° angle
found on U.S. standard straight threads. There are 6 to 8
threads per inch for the sanitary fittings.
Identifying Threads
Normal Engagement Length of NPT Thread in Inches (A) *
Pipe Size
A
⅛"
¼"
¼"
3/8"
3/8"
3/8"
1/2"
1/2"
3/4"
9/16"
1"
11/16"
1-¼"
11/16"
1-1/2"
11/16"
2"
3/4"
Pipe Size
A
2-1/2"
15/16"
3"
1"
4"
1-⅛"
5"
1-¼"
6"
1-5/16"
8"
1-7/16"
10"
1-5/8"
12"
1-3/4"
Size
Pipe OD
Tapered Threads
Straight Threads
NPT
BSPTr
Acme 3A
TPI
TPI
TPI
ODM (max) IDF (min)
⅛"
.405
27
28
¼"
.504
18
19
3/8"
.675
18
19
1/2"
.840
14
14
3/4"
1.050
14
14
1"
1.315
11.5
11
8
1.462
1.352
1-¼"
1.660
11.5
11
1-1/2"
1.900
11.5
11
8
1.994
1.884
2"
2.375
11.5
11
8
2.526
2.416
2-1/2"
2.875
8
11
8
3.058
2.948
3"
3.500
8
11
8
3.590
3.480
4"
4.500
8
11
6
4.695
4.544
5"
5.563
8
11
6"
6.625
8
11
8"
8.625
8
10"
10.750
8
12"
12.750
8
ODM -- Outside Diameter of
the Male
IDF -- Inside Diameter of the
Female
TPI -- Threads Per Inch
GHT (3/4") -- 1.0625 ODM,
11-1/2 TPI
NPT = National Pipe Taper
BS = British Standard