BSP Tapered Male x JIS BSP Male Straight Adaptor

BSPT into a local port, JIS BSP out to a Japanese machine. The JIS pattern uses a BSPP thread with a 60° cone and will not mate with a standard BSP part despite the thread matching.

Brand: Ayrtec – mild steel body with a plated finish, manufactured to the standards listed below.

Watch: How to Identify Hydraulic Hose Fittings and Hydraulic Adaptors JIC and BSP

Thread Standards

• BSP Tapered Male – BSPT to ISO 7 / BS 21. It seals on the tapered thread itself, so it needs PTFE tape or a liquid thread sealant.
• JIS BSP Male (inverted BSP) – JIS B8363 – BSPP thread to ISO 228 with a 60° cone seat. It seals on the 60° cone, and although the thread matches a standard BSP the seat is not interchangeable with it.

How to Choose

• The JIS thread is BSPP and screws into standard BSP fittings. The seat does not match. Always check the cone.
• Tape or sealant on the BSPT end only. The JIS end seals on its cone.
• JIS ports rarely appear alone - if one is JIS, expect the machine to be.

Technicians Advice

This is the fitting that solves the mystery leak on Japanese gear. If a BSP-looking joint has been retaped twice and still seeps, someone has fitted a standard BSP part into a JIS port. The thread feels right and the cones never seat.

Where You’ll Find It

• BSP Tapered Male – Older Australian and British pipework, gauge ports, tank and return lines, and cast pump and gearbox housings.
• JIS BSP Male (inverted BSP) – Japanese-built machinery – Komatsu, Hitachi, Kobelco, Sumitomo, Kubota – where it is often just called JIS or inverted BSP.

Cross-Reference

• BSP Tapered Male – BSPT to ISO 7 / BS 21, written R for male. Sometimes labelled PT or BSP taper.
• JIS BSP Male (inverted BSP) – JIS B8363 60° cone on a BSPP (ISO 228) thread. Also written JIS BSP or inverted BSP.

Parker, Gates, Aeroquip and Ryco all manufacture to these same standards under their own part numbering, so a fitting built to the standard above will mate with theirs.

Cross-references are given at series level as a guide to the standard, not as a part-for-part substitution. Always confirm the thread form, size and seal type against the port before ordering.

📐Dimensions & thread sizes – every size in this range

← Swipe the table sideways to see every measurement →

Part code	A	B	L	H1	Material	Finish
BTM-BJM-0404	1/4" JIS BSPP	1/4" BSPT	38mm	17mm	Mild steel	Plated finish
BTM-BJM-0606	3/8" JIS BSPP	3/8" BSPT	41mm	19mm	Mild steel	Plated finish
BTM-BJM-0808	1/2" JIS BSPP	1/2" BSPT	49mm	22mm	Mild steel	Plated finish
BTM-BJM-1212	3/4" JIS BSPP	3/4" BSPT	54mm	30mm	Mild steel	Plated finish
BTM-BJM-1616	1" JIS BSPP	1" BSPT	64mm	36mm	Mild steel	Plated finish

Key: L overall length, H1 centre to face 2. Measurements in millimetres unless shown otherwise. Thread columns show what each end mates with. Dimensions are nominal – check critical clearances against the part.

Downloads

📄 Thread Identification Chart (PDF)

Express shipping Australia-wide. We dispatch daily to New South Wales, Victoria, Queensland, Western Australia, South Australia, Tasmania, the Australian Capital Territory and the Northern Territory – Sydney, Melbourne, Brisbane, Perth, Adelaide, Hobart, Canberra and Darwin, plus regional and remote sites.

Need a hand? Call 1300 146 737 or email sales@mhfgc.com.au – real technicians, real answers.