Overview
JIS B 1575 grease fittings are metric hydraulic grease nipples for machinery built to Japanese dimensional standards: a conical head, a ball check and a coarse metric thread. If your equipment is European, start with the metric DIN 71412 grease nipple family – same hydraulic head, finer thread pitch. For a single-size deep dive, see the M6 grease nipple size page or the M8 grease nipple size page.
What JIS B 1575 Specifies
JIS B 1575 is the Japanese product dimension standard for hydraulic-type grease nipples: the conical head a grease gun coupler clamps onto, the spring-loaded ball check behind it, and the coarse metric thread that anchors the nipple in the housing. The series covers four sizes: M6x1.0, M8x1.25, M10x1.5 and M12x1.75.
JIS Coarse Threads vs DIN 71412 Fine Threads
Both standards share the hydraulic head concept but not the thread: JIS specifies coarse pitches, DIN 71412 fine pitches at the same nominal diameters. A thread gauge that fits one will not fit the other, so check pitch before installation.
| Nominal size | JIS B 1575 thread | DIN 71412 thread |
|---|---|---|
| M8 | M8x1.25 | M8x1 |
| M10 | M10x1.5 | M10x1 |
| M12 | M12x1.75 | M12x1.5 |
A JIS nipple must not be forced into a DIN tapped hole. Confirm the thread form and sealing arrangement when ordering.
Straight, 45° and 90° Configurations
Straight nipples need clearance above the mounting face and suit open housings. 45° angles the head away from the boss where a hose or guard sits close. 90° keeps the head nearly parallel to the face, minimizing protrusion behind covers. Match the angle to the space your coupler can access; an angle chosen from the drawing alone often blocks the coupler in service.
Material, Plating and Ball Check
The body is S45C carbon steel under a blue-white trivalent zinc layer 8 – 12 micron thick for indoor and general industrial duty. The conical head is hardened to 500 HV min to withstand repeated coupler clamping. A spring-loaded ball check behind the head opens under injection pressure and reseats when the coupler comes off, keeping dirt and wash water out.
Honest Limitations
- These nipples fit metric JIS threaded ports; imperial or NPT ports belong on a different page.
- Zinc plating suits indoor and general industrial use; for marine or chemical exposure, ask about the stainless steel option when ordering.
- We state no pressure rating here; confirm the working pressure of your grease gun when ordering.
- Confirm the thread form and sealing arrangement when ordering.
If you are unsure whether your equipment is JIS or DIN, send us the thread marking from your old nipple and we will point you to the right page.
Frequently Asked Questions
My machine is European – do I belong on this page?
Probably not. European equipment normally uses DIN 71412 fine-pitch nipples; start at the metric DIN 71412 grease nipple family. Come back only if the builder specifies JIS threads.
What is JIS B 1575?
The Japanese product dimension standard for hydraulic-type grease nipples: conical head, ball check and a coarse metric thread series for machinery built to Japanese standards.
How do JIS and DIN 71412 threads differ?
Only in pitch. At the same nominal size, JIS uses coarse pitches – M8x1.25, M10x1.5, M12x1.75 – while DIN 71412 uses fine pitches – M8x1, M10x1, M12x1.5. The heads look alike, so the thread tells them apart.
Can I install a JIS nipple in a DIN tapped hole?
No. A coarse JIS thread will not seat in a fine DIN hole; forcing it damages nipple and housing. Check pitch with a thread gauge before ordering; look-alike heads are a warning sign.
How do I confirm which thread my equipment has?
Read the service manual first. If it is silent, unscrew the old nipple and measure diameter and pitch, or match it against a known nipple. When in doubt, confirm the thread form and sealing arrangement when ordering.
Will my grease gun coupler fit these nipples?
A standard hydraulic coupler clamps the conical head, so it fits JIS B 1575 and DIN 71412 nipples alike. Button-head nipples per DIN 3404 and flush-type per DIN 3405 need different nozzles; match the nozzle to the head type.
Which angle should I choose: straight, 45° or 90°?
Pick by clearance. Straight suits open housings with room above the boss; 45° clears nearby hoses and guards; 90° minimizes protrusion behind covers. Check that your coupler can grip the head at its installed angle.
Should I choose S45C steel or stainless steel?
For indoor and general industrial duty, zinc-plated S45C is the standard choice. For marine, washdown or chemical exposure, specify the stainless steel option when ordering; we will point you to the right family.
Can I mix metric JIS nipples with imperial threads?
Do not mix them. Metric and imperial threads differ in diameter and pitch, and an approximate fit will not seal or hold. Tell us the port thread you measured and we will confirm the correct nipple before you order.
Who makes these JIS grease fittings?
IsoHiTech Lubrication Systems, founded in 2023, engineering since 2006, supplies metric grease nipples, centralized lubrication components and accessories. For selection help, contact inquiry@isohitech.com.
