JIS Threads

JIS Threads

JIS THREADS

JIS is JAPANESE INDUSTRIAL STANDARDS
There are four popular coupling styles in Japan.
 
1. JIS Tapered Pipe Thread.
3. Komatsu 30° flare (Female Internal Cone Seat).   
  Threads commonly used on Komatsu equipment (30° cone) have metric thread form.

MALE THREAD
OD & PITCH		 DASH
SIZE		 FEMALE
THREAD ID
mm   mm
M14 x 1,5 -1415 12,5
M18 x 1,5 -1815 16,5
M22 x 1,5 -2215 20,5
M24 x 1,5 -2415 22,5
M30 x 1,5 -3015 28,5
M33 x 1,5 -3315 31,5
M36 x 1,5 -3615 34,5
M33 x 1,5 -3315 31,5
 

  
Thread form per JIS B 0207
4. Komatsu Style Flange Fitting JIS B 8363
  The Komatsu style Flange fitting is nearly identical to, and fully interchangeable with, the SAE Code 61 flange fitting*. The O Ring dimensions are different between all sizes. When replacing a Komatsu style flange with an SAE style flange, an SAE style O Ring must always be used. *5/8” is not in the SAE Standards.
  The Japanese tapered pipe thread connector is identical to and interchangeable with the BSPT (tapered) connector. The Japanese male thread does not have a 30° Flare, and will not mate with the BSPP female swivel with conical seat.
The seal on the Japanese tapered pipe thread connector is made on the threads. Use of a thread sealant is recommended.
 

Thread form per JIS B 0203 (identical to BSPT)
Refer to BSPT section for dimensions of threads.
2. JIS 30° Flare (Female Internal Cone Seat).
  This connection uses a 60° concave (inverted) seat and British Standard Pipe Parallel threads. They are not interchangeable with BSPP conical seat couplings, because the cone seats are opposite.


Thread form per JIS B 0202 (identical to BSPP)
Refer to BSPT section for dimensions of threads.
BSPT & BSPP Theads Dimensions

BSPT & BSPP
SIZE & PITCH		 DASH
SIZE		 BSPT MALE
THREAD OD		 BSPP MALE
THREAD OD		 BSPT FEMALE
THREAD ID		 BSPP FEMALE
THREAD ID
inch - TPI   mm inch mm inch mm inch mm inch
1/8 - 28 -02 9,5 0.37 9,6 0.38 8,4 0.33 8,6 0.34
1/4 -19 -04 12,8 0.50 13,0 0.51 11,2 0.44 11,9 0.47
3/8 - 19 -06 16,3 0.64 16,5 0.65 14,7 0.59 15,2 0.60
1/2 - 14 -08 20,4 0.80 20,8 0.82 18,3 0.72 19,1 0.75
5/8 - 14 -10 22,5 0.89 22,8 0.90 20,6 0.81 20,8 0.82
3/4 -14 -12 25,9 1.02 26,3 1.04 23,9 0.94 24,6 0.97
1 - 11 -16 32,6 1.28 33,1 1.30 29,7 1.17 30,7 1.21
1.1/4 - 11 -20 41,1 1.62 41,8 1.64 38,6 1.52 39,4 1.55
1.1/2 - 11 -24 47,0 1.85 47,7 1.88 44,5 1.75 45,5 1.79
2 - 11 -32 58,6 2.31 59,5 2.34 56,4 2.22 57,4 2.26
2.1/2 - 11 -40 74,1 2.92 75,1 2.95 71,9 2.83 72,6 2.86
3 -11 -48 86,6 3.41 87,9 3.46 84,6 3.33 85,4 3.36
  Thread size refers to the nominal bore of the pipe. Subtract approx. 1/4" (6 mm) from thread dia meter measurement for nominal pipe size.
Pitch is Threads Per Inch (TPI). "Gas", "R" & "G" also refer to BSP. "Male Iron (Pipe)" may be BSP or NPT.