Hi have a SK50UR-2. Need a small pipe for the spool block. 1/4" bsp tapping in the block, but the hydraulic pipes am un sure of fittings. Thought they were JIC but 1/2" to small 9/16" to big. Measured threads 20tpi X 1/2" which is cycle thread. Any thoughts?
On bigger machines Kobelco uses ''JIS'' fittings, which stands for Japanese Industrial Standard. It looks like JIC fittings but with different taper angle and threads.
I seem to remember all the Kobelco machines using British Standard Parallel fittings sometimes with a ball nose type coupler on the larger fittings. Komatsu was the only machines I worked on that routinely used JIS fittings.
Update on this, we have found that the thread is BSP, on first glance looks like a JIC fitting, with the very pronounced nose beyond the thread on a male fitting. As said 1/2" JIC to small, but when we checked the thread profile against a 1/4"BSP fitting we could see it was the same, so will this be the same as JIS?
JIS and BSP does have the same thread size
So we no see
I believe JIS threads are measured in millimeters between the high spots on the threads. As I recall BSPP is in threads per inch. Someone correct me if I am wrong.
There are two Japanese JIS specs, there's the JIS code B 0207 that's a 30 degree flare with metric threads, this one is the Komatsu JIS fitting. The other is JIS code B 0202 with 30 degree flare and BSPP threads, that's the JIS fitting that Kobelco uses on the hose fittings. Very early Kobelco machines used the BSPP ball nose fittings. I'm not sure about the 1/2" x 20 TPI you mentioned, that's the threads for 5/16" SAE straight threads and I've never known Kobelco to use SAE threads?
Thanks Willie!
My pleasure John C, I know you're an old Komatsu wrench bender and I for one am glad you're here with your knowledge of the Kommie machines.
It cost me $150 and 6 hours to figure out jis can be bspp or metric thread. The kicker was I ended up looping hose back and not needing plugs and caps that day anyway. After that I bought plug and cap kits for both thinking that jis bspp would work on case. I have never touched a kobelco but have caps and plugs when I do lol. When I got o-ring face seal kit I thought I was pretty covered.... Got to love the game.
Yeah brother, welcome to our world, having the plugs/caps for NPT, BSPT, BSPP, JIC, JIS x 2, ORFS, DIN, SAE, code 61 and code 62 four bolt flange, and whatever we don't have for that we keep a supply of plastic plugs that we've acquired over the years to plug that hole.