JIS for pipe threads

[eklimek]

I have previously written about the JIS for screws; essentially a cross head resembling Phillips with a metric thread. ( viewtopic.php?t=15547 )

In attempting to install a oil pressure gauge on my 1972 cb350f I fell down another rabbit hole and found another JIS, this time for pipe thread.

In brief, pipe can be parallel or tapered. Tapered seals by thread closure and uses sealants. Parallel thread seals on the landing face or with an "O" ring. Sometimes one finds pipe in water applications such as a dish washer attachment using teflon tape on the thread to improve seal. Teflon tape is not recommended for other applications because the bits of tape can and do become dislodged.

JIS for pipe thread adopted BSPT (British Standard Pipe Tapered). This has also been renamed as ISO 7/1.

BSPT closely resembles NPT, but isn't. Those inclined to read the original standard will find it published under Japanese Industrial Standard JIS B 0203 (1966) in English translation. It is copyrighted.

https://law.resource.org/pub/jp/ibr/jis ... e.1982.pdf

NPT (also known as ASME B1.20.1)
■ Truncation of roots and crests are flat
■ 60° thread angle
■ Pitch is measured in threads 27 per inch

BSPT or ISO 7/1 (also known as EN 10226‑1 and JIS B0203)
■ Truncation of roots and crests are rounded
■ 55° thread angle
■ Pitch is measured in threads 28 per inch

BSPT or JIS or ISO 7/1

Although the pipe thread are similar in that both are tapered (1 degree 47 minutes), they differ in pitch (27 vs 28 per inch) and morphology ( 55 vs 60 degree thread angle and truncation). Pitch changes with size.

[eklimek]

These are the steps for one possible solution to tapping the oil pressure switch on a Honda to install a gauge.

Run the -3 stainless to a convenient site to mount the sensor.

[Ed Brock]

eklimek,
No to your question. On Japanese bolts there are numbers. Those numbers stand for bolt hardness, like we have here, grade 5 or grade 8 or etc. Those numbers are what I am talking about at the end of my post.
The hydraulic thread mismatch I was referring to, has to do with your post. You cover the thread/pitch well, but I'm also talking about the seat angle of the hydraulic fitting as well. As JIS has become more common this issue has resolved itself by people in the hydraulic hose business. Hope that clarifies matters.

On a different matter, I have the bolt number cart I discussed, I am trying to copy it to this site. So far no luck, will keep trying. I could you some help. I'm a dinosaur, this sort of stuff is foreign to me.
Ed

[DenverWinger]

Honda uses BSPT threads on the oil sender, most oil senders use NPT. Here's a link for a BSPT to NPT adapter.... I used one on my 1500 to add an oil pressure gauge.

BSPT to NPT adapter
http://k-tuned.3dcartstores.com/Oil-Pre ... p_612.html

BSP vs NPT
NPT threads are common in the United States and a few other countries, BSP threads are widely used in many other countries.

BSPT -British Standard Pipe Taper
BSPP -British Standard Pipe Parallel
NPT -National Pipe Taper
NPS -National Pipe Straight
While the actual specified outside diameters of American National Pipe differ slightly from those of British Standard Pipe, either thread may reliably be cut onto a pipe of its respective trade size. BSPT equivalent is NPT and BSPP’s equivalent is NPS.

Never swap threads if it is a high pressure application.

NPT/NPS and BSP threads are not compatible due to the differences in their thread forms, and not just the fact that most sizes have a different pitch. NPT/NPS threads have a 60° angle and have flattened peaks and valleys (Sellers thread form) where as BSP threads have a 55° angle and have rounded peaks and valleys (Whitworth thread form).

[Rambozo]

Don't forget NPTF.
That's the nice thing about industrial standards, there are so many to chose from.

BTW:
Metric bolt numbering, ie. 8.8, 9.8, 10.9, 12.9 This is the approximate tensile strength in hundreds of Mega Pascals.

[DenverWinger]

Then there has to be corresponding BSPT fine.

..... So they'll create yet another standard to "Unify" them all, too!