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HAN-HRHN0806

Hansen - Reducing Hex Nipple - HRHN

Size

Big Water Tanks is an official stockist of Hansen Products — New Zealand-made True Fit threaded fittings for plumbing, irrigation, rainwater, farm and marine water systems. The Hansen Reducing Hex Nipple (HRHN) joins two female threads of different sizes, with a larger BSPT male thread on one end, a smaller BSPT male thread on the other and a hex in the middle, in 28 size combinations from 8 × 6mm (1/4" × 1/8") up to 100 × 80mm (4" × 3").

Hansen True Fit Reducing Hex Nipple (HRHN): BSPT Male × Male Thread Reducer

A reducing hex nipple joins two female threads of different sizes, for example a 25mm (1") female valve or tank outlet to a 15mm (1/2") female fitting. The Hansen HRHN has a larger tapered BSPT male thread on one end (T1), a smaller tapered BSPT male thread on the other end (T2) and a hex in the middle for a spanner. Hansen describes it as "used as a reducing join, to join two female threads". It is moulded in New Zealand from glass fibre reinforced nylon, is rated up to 16 bar at 20°C in sizes up to 50mm, and is tested to AS/NZS 4020:2018 for contact with drinking water. Below you will find the full dimension table for every size we sell, the pressure and temperature ratings, how to pick the right size, and installation tips straight from Hansen.

Quick Facts

  • Thread type: BSPT (tapered) male × BSPT male, larger thread one end, smaller thread the other
  • Sizes: 28 combinations, 8mm (1/4") to 100mm (4") larger thread
  • Max working pressure @ 20°C: 16 bar up to 50mm · 12 bar at 65mm · 10 bar at 80–100mm
  • Max temperature: 60°C (140°F) — cold water use
  • Drinking water: AS/NZS 4020:2018 tested and WRAS approved range
  • Made in: New Zealand (Hansen Products, Whangarei)

Key Features & Benefits

  • Precision Tapered Threads: Heavy duty BSPT tapered threads on both ends give a strong, reliable seal
  • Strong Glass Fibre Reinforced Nylon: Weather, termite, fungi and bacteria resistant, and strong enough to minimise potential cross threading
  • Safe for Drinking Water: Made from a raw material approved for potable (drinkable) water; tested to AS/NZS 4020:2018
  • Above or Below Ground: Suitable for varying operating pressures and temperatures (see the pressure table)
  • Strong, Lightweight & Compact: UV stabilised black nylon with a centre hex for spanner tightening
  • Huge Size Range: 28 sizes from 1/4" × 1/8" up to 4" × 3". Sizes 15mm–50mm are stocked in store; we hold limited stock of other sizes and can order them in if needed
  • Common Applications: Horticulture, agriculture, irrigation, marine, rainwater and plumbing
  • Largest Range: Part of the largest range of commercial quality threaded pipe fittings in the Southern Hemisphere, available in a variety of thread combinations and connections
  • Hansen Limited Lifetime Warranty: All Hansen manufactured products carry Hansen's Limited Lifetime Warranty (conditions apply)
  • New Zealand Made

Pressure Rating

Larger Thread Size Max @ 20°C kPa @ 20°C @ 40°C @ 60°C
6mm – 50mm (1/8" – 2") 16 bar 1,600 kPa approx. 12 bar approx. 8 bar
65mm (2 1/2") 12 bar 1,200 kPa approx. 9 bar approx. 6 bar
80mm – 100mm (3" – 4") 10 bar 1,000 kPa approx. 7.5 bar approx. 5 bar

Ratings are by the size of the larger thread (T1). The 20°C figures are Hansen's published maximum working pressures. The 40°C and 60°C figures are read from Hansen's straight-line derating graph and are approximate. Ratings apply to fittings used with water only and installed to Hansen's specifications. Hansen tests its products for cold water use up to 60°C (140°F) and does not recommend use above 60°C.

Materials & Standards

Material

Body: high quality glass fibre reinforced nylon (the AS/NZS 4020 test report lists the compound as Polyamide 6 Glass Fibre Reinforced — Durethan BKV 15F). Black, UV stabilised.

AS/NZS 4020:2018 — Products in Contact with Drinking Water

The Hansen EasyFit and True Fit range passed AS/NZS 4020:2018 testing (taste, appearance, growth of aquatic micro-organisms, cytotoxic activity, metals and organic compounds) at the Australian Water Quality Centre, report 356792, completed 7 March 2023.

WRAS Approved (UK)

The "Hansen True Fit" range of black plastic threaded fittings holds WRAS (Water Regulations Approval Scheme) approval number 251102715, valid 1 November 2025 to 30 November 2030. WRAS approval shows a fitting complies with the UK water fittings regulations for use on drinking water supplies.

Delivery or Collection

Stock Sizes 15mm–50mm are stocked in store. We hold limited stock of other sizes, and can order them in if needed.
Delivery Courier nationwide. Shipping is calculated at checkout based on your location.
Collections Available from 21 Akatea Road, Glendene, Auckland.

How to Choose & Measure Your Thread

Hansen sizes are nominal BSP sizes, not the measured diameter of the pipe or thread. A "15mm" thread is a 1/2" BSP thread, and it measures about 21mm across the outside of the male thread.

Step 1: Find the larger thread (T1)

This is the larger female port you are screwing into (e.g. a 1" valve or tank outlet). Measure the inside of the female port, or the outside of a male thread that already fits it, and match it to the table below.

Step 2: Find the smaller thread (T2)

This is the smaller female fitting you want to connect (e.g. a 1/2" female fitting). If both female threads are the same size, use a Hansen Hex Nipple (HSN) instead.

Step 3: Pick the code

The code is simply HRHN plus T1 then T2 in mm: 25mm × 15mm = HRHN2515, 1/4" × 1/8" = HRHN0806.

BSP Size Hansen mm Male Thread OD (approx.) Threads per Inch
1/8" 6mm 9.7mm 28
1/4" 8mm 13.2mm 19
3/8" 10mm 16.7mm 19
1/2" 15mm 21.0mm 14
3/4" 20mm 26.4mm 14
1" 25mm 33.2mm 11
1 1/4" 32mm 41.9mm 11
1 1/2" 40mm 47.8mm 11
2" 50mm 59.6mm 11
2 1/2" 65mm 75.2mm 11
3" 80mm 87.9mm 11
4" 100mm 113.0mm 11

Male thread outside diameters and threads per inch are the standard BSP (ISO 7) values, rounded. Tapered BSPT threads seal on the taper, so measure near the end of the thread.

Installation in Brief

  • Seal every thread: Use a non-hardening thread sealant that is compatible with plastic (Hansen recommends Loctite 5331) or PTFE thread tape
  • Hand tight + 1 to 2 turns: Tighten until firm with a spanner on the hex — no more. Do not over-tighten
  • Support your pipework: All pipe work must be adequately supported
  • Metal fittings: Hansen True Fit fittings can be used with metal fittings

Hansen's Threaded Fitting Handy Tips: how to apply thread tape and tighten True Fit fittings.

Full step-by-step guide: Hansen threaded fitting installation guide.

Full Size & Dimension Table — All 28 Hansen Reducing Hex Nipples

T1 is the larger male thread and T2 is the smaller male thread, one at each end. Both are BSPT tapered threads. Dimensions are from Hansen's HRHN drawing: hex across flats (a) and overall length (b), in mm. Choose the code from the Size drop-down above.

Reading the drawing:

  • a: hex size across flats (the spanner size)
  • b: overall length
  • T1: larger BSPT male thread
  • T2: smaller BSPT male thread
Hansen Reducing Hex Nipple HRHN dimension drawing showing hex across flats (a), overall length (b), larger male thread (T1) and smaller male thread (T2)
Hansen Code Metric Size Imperial Size Larger Thread (T1) Smaller Thread (T2) Hex Across Flats (mm) Length (mm) Max Pressure @ 20°C
BSPT male BSPT male
HRHN0806 8 × 6mm 1/4" × 1/8" 1/4" 1/8" 14 31 16 bar
HRHN1006 10 × 6mm 3/8" × 1/8" 3/8" 1/8" 18 33 16 bar
HRHN1008 10 × 8mm 3/8" × 1/4" 3/8" 1/4" 18.5 34.5 16 bar
HRHN1506 15 × 6mm 1/2" × 1/8" 1/2" 1/8" 22.5 37.3 16 bar
HRHN1508 15 × 8mm 1/2" × 1/4" 1/2" 1/4" 22.5 39 16 bar
HRHN1510 15 × 10mm 1/2" × 3/8" 1/2" 3/8" 26 50.5 16 bar
HRHN2010 20 × 10mm 3/4" × 3/8" 3/4" 3/8" 31 55.5 16 bar
HRHN2015 20 × 15mm 3/4" × 1/2" 3/4" 1/2" 28.5 48 16 bar
HRHN2515 25 × 15mm 1" × 1/2" 1" 1/2" 35 51.5 16 bar
HRHN2520 25 × 20mm 1" × 3/4" 1" 3/4" 35.5 54 16 bar
HRHN3220 32 × 20mm 1 1/4" × 3/4" 1 1/4" 3/4" 45 66 16 bar
HRHN3225 32 × 25mm 1 1/4" × 1" 1 1/4" 1" 44 60 16 bar
HRHN4020 40 × 20mm 1 1/2" × 3/4" 1 1/2" 3/4" 51.5 68 16 bar
HRHN4025 40 × 25mm 1 1/2" × 1" 1 1/2" 1" 50 64.5 16 bar
HRHN4032 40 × 32mm 1 1/2" × 1 1/4" 1 1/2" 1 1/4" 50 62 16 bar
HRHN5020 50 × 20mm 2" × 3/4" 2" 3/4" 63.5 73 16 bar
HRHN5025 50 × 25mm 2" × 1" 2" 1" 63 74 16 bar
HRHN5032 50 × 32mm 2" × 1 1/4" 2" 1 1/4" 63 73 16 bar
HRHN5040 50 × 40mm 2" × 1 1/2" 2" 1 1/2" 62.5 70 16 bar
HRHN6532 65 × 32mm 2 1/2" × 1 1/4" 2 1/2" 1 1/4" 79 79.5 12 bar
HRHN6540 65 × 40mm 2 1/2" × 1 1/2" 2 1/2" 1 1/2" 79 77 12 bar
HRHN6550 65 × 50mm 2 1/2" × 2" 2 1/2" 2" 79 78 12 bar
HRHN8040 80 × 40mm 3" × 1 1/2" 3" 1 1/2" 91.5 86 10 bar
HRHN8050 80 × 50mm 3" × 2" 3" 2" 91.5 86 10 bar
HRHN8065 80 × 65mm 3" × 2 1/2" 3" 2 1/2" 92 85 10 bar
HRHN10050 100 × 50mm 4" × 2" 4" 2" 116.5 101.5 10 bar
HRHN10065 100 × 65mm 4" × 2 1/2" 4" 2 1/2" 117 100 10 bar
HRHN10080 100 × 80mm 4" × 3" 4" 3" 117 98.5 10 bar

Chemical Compatibility

Using your fittings with anything other than water? Check Hansen's chemical resistance chart for True Fit threaded fittings before you install. Pool and spa chlorine, bleach, strong acids and oxidising agents all attack the material.

View Chemical Compatibility Chart

Installation Guide

Step-by-step thread sealing and tightening, do's and don'ts, and how to pressure test a new Hansen threaded joint, with Hansen's handy tips video.

View Installation Guide

Frequently Asked Questions

What size reducing hex nipple do I need to join a 25mm (1") female thread to a 15mm (1/2") female thread?

You need the Hansen HRHN2515. It has a 1" (25mm) BSPT male thread on one end and a 1/2" (15mm) BSPT male thread on the other. It is 35mm across the hex flats and 51.5mm long, and it is rated to 16 bar at 20°C. The code always reads larger thread then smaller thread in mm, so 32mm to 20mm is HRHN3220 and 50mm to 25mm is HRHN5025.

Reducing hex nipple, hex nipple or reducing bush: which do I need?

A Hansen reducing hex nipple (HRHN) is male on both ends and joins two female threads of different sizes. If both female threads are the same size, use a Hansen Hex Nipple (HSN). To step a female thread down to a smaller female thread, use a Reducing Bush (HRB). To join two male threads, use a Hex Socket (HSS).

Is a Hansen reducing hex nipple safe for drinking water?

Yes. Hansen True Fit threaded fittings are made from a raw material approved for potable (drinkable) water. The range passed AS/NZS 4020:2018 testing for products in contact with drinking water (Australian Water Quality Centre report 356792, 2023), and the True Fit range holds UK WRAS approval number 251102715, valid to 30 November 2030. Hansen notes the material is suitable for domestic water, not pool or spa water.

Do I need thread tape on nylon fittings?

Yes. Hansen says to use a thread sealant on all threaded connections, even though the threads are tapered. Use either a thread sealing paste or PTFE (Teflon) tape. Hansen recommends Loctite 5331. The right sealant is non-hardening, compatible with plastic, and doesn't add slipperiness that encourages over-tightening. Wrap tape clockwise when looking at the end of the male thread, starting just back from the first thread.

How tight should I tighten a Hansen threaded fitting?

Hand tight plus one to two turns, and no more. Screw the fitting in by hand until it is firm, then use a spanner or pipe grip on the hex for one to two more turns. Hansen is clear on this: do not over-tighten. Hansen's handy tips video makes the same point: the aim is a good seal, not maximum tightness.

What pressure is a Hansen reducing hex nipple rated to?

At 20°C, Hansen rates True Fit threaded fittings at 16 bar (1,600 kPa) for sizes from 6mm to 50mm, 12 bar (1,200 kPa) for 65mm, and 10 bar (1,000 kPa) for 80mm to 100mm. On a reducing hex nipple the rating is set by the larger thread (T1). Pressure ratings fall as temperature rises. At 60°C, Hansen's graph shows about 8, 6 and 5 bar respectively. The ratings apply to water only, with the fitting installed to Hansen's specifications.

Can I use a Hansen reducing hex nipple on hot water?

No. Hansen tests its products for cold water use up to a maximum of 60°C (140°F) and does not recommend use above 60°C, because plastic expands as temperature rises. Fittings that fail above 60°C are not covered by Hansen's Limited Lifetime Warranty — so do not use them on hot water lines that run above 60°C.

Are Hansen reducing hex nipple threads BSP or NPT?

Hansen reducing hex nipples are BSPT x BSPT, meaning British Standard Pipe tapered threads on both ends. This is the standard pipe thread used in New Zealand and Australia. BSP and NPT threads have different thread angles and pitches in most sizes, so don't assume an NPT thread will seal in a BSPT fitting.

Does 15mm mean the reducing hex nipple fits 15mm pipe?

No. Hansen's mm sizes are nominal BSP thread sizes, not pipe outside diameters. 15mm is a 1/2" BSP thread, and its male thread measures about 21mm across. Likewise, 20mm is 3/4" (about 26.4mm), 25mm is 1" (about 33.2mm) and 50mm is 2" (about 59.6mm). Match the thread, not the pipe, then use the correct pipe fitting for your pipe type.

Can I use Hansen nylon fittings with brass or galvanised fittings?

Yes. Hansen says True Fit fittings can be used with metal fittings. Use a plastic-compatible thread sealant, tighten to hand tight plus one to two turns, and make sure all pipework is properly supported so the nylon fitting is not carrying the weight of metal pipe or valves.

Can I use a Hansen reducing hex nipple on a swimming pool or spa?

No. Hansen advises that the high chlorine concentrations in pool and spa water will attack the fitting material. True Fit fittings are only suitable for domestic water, and fittings used on pools or spas are not covered by Hansen's Limited Lifetime Warranty. Their chemical resistance chart also rates bleach, halogens and oxidising agents as bad. See our Hansen chemical compatibility page.

Can Hansen threaded fittings be buried or used under a driveway?

Hansen True Fit fittings are suitable for use above or below ground. However, Hansen does not recommend using any True Fit fittings under driveways, paths or foundations. All pipework must be adequately supported.