BSP Bulkhead Locknuts

Replacement locknuts for BSP bulkhead fittings. The nut that clamps the bulkhead body to the panel.

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

Watch: Exploring Hydraulic Adaptors Part 1: Difference Between Branch Tee & Run Tee, Elbows Short and Long

Thread Standards

• BSP Bulkhead Male – BSP parallel thread on a bulkhead body with a locknut. It seals on a bonded washer or a 60° cone in the mating part; the bulkhead thread and locknut only clamp it to the panel.

How to Choose

• This is a spare part, sold on its own so a damaged one does not mean replacing the whole assembly.
• The locknut clamps only. It does no sealing, so a leak at a bulkhead is never cured by tightening it.
• Match the nut to the bulkhead thread, not to the line size.

Technicians Advice

Keep a few spares. The locknut is the part that gets lost when a machine is stripped, and a bulkhead without one is just a fitting hanging in a hole waiting to fatigue the line.

Where You’ll Find It

• BSP Bulkhead Male – panel and guard pass-throughs on Australian and British-built machinery, tank installations and trailer plumbing where BSP is the house standard.

Cross-Reference

• BSP Bulkhead Male – BSPP to ISO 228 on a bulkhead body. Sometimes written BSP BH. The long thread under the shoulder is for the panel and locknut, not for sealing.

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	Hex	Material	Finish
BLN-04	19mm	Mild steel	Plated finish
BLN-06	22mm	Mild steel	Plated finish
BLN-08	27mm	Mild steel	Plated finish
BLN-12	32mm	Mild steel	Plated finish
BLN-16	41mm	Mild steel	Plated finish
BLN-20	50mm	Mild steel	Plated finish
BLN-24	55mm	Mild steel	Plated finish

Key: Hex across flats. 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)

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