A lubrication nipple extension is a flexible tube assembly that moves a grease point to a position where a grease gun coupler connects comfortably: a stainless threaded inlet replaces the original nipple, the tube routes around the obstruction, and a standard nipple sits where the operator can work safely.
A rigid threaded extension only moves the nipple in a straight line; a flexible extension routes the line around guards, covers, and obstructions. If the existing nipple is already directly accessible, a flexible extension adds no benefit.
Inlet Thread Options and SS316 Construction
The inlet piece is machined from SS316 stainless steel, the specified inlet for chloride and marine environments, rated to +200°C. Standard threads are M6 x 1.0, M8 x 1.25, and 1/8″ NPT; BSP and other forms are available on request. Tightening torque: 5 – 8 Nm (M6 x 1.0), 8 – 12 Nm (M8 x 1.25), 8 – 10 ft-lbs (1/8″ NPT). Confirm the thread form and sealing arrangement when ordering.
Choosing Tube Length and Outside Diameter
The tube is PA12 or polyurethane (PU), both oil resistant, in 4 mm, 6 mm, and 8 mm outside diameters. Standard lengths are 200 mm, 500 mm, and 800 mm; 1,000 mm is the recommended upper limit for manual greasing. The same material is listed separately as the 6 x 1.5 mm polyamide tube.
| Assembly length | Typical use |
|---|---|
| 200 mm | Short relocation, nipple moved just clear of an obstruction |
| 500 mm | Standard duty, point routed to a nearby service position |
| 800 mm | Deep-seated bearings and points behind full guards |
| Tube outside diameter | Typical use |
|---|---|
| 4 mm | Light-duty points and compact routing spaces |
| 6 mm | General-purpose choice for most bearings |
| 8 mm | Larger grease volumes and longer tube runs |
Outlet Fitting and System Ratings
The standard outlet is a DIN 71412 hydraulic-type grease nipple, taking a manual coupler with an 8 – 11 mm jaw directly; a hose barb outlet can be supplied to specification. For matching stainless outlets, see the stainless steel grease nipples range.
The assembly is rated up to 10,000 PSI (689 bar), handles NLGI 0 – 3 greases, and covers the 3 – 10,000 PSI output of manual grease guns; working temperature is -40°C to +80°C, set by the tube.
Installation, Routing, and Clamping
Clamp the line at approximately 300 mm intervals against vibration wear, clear of sharp edges, hot surfaces, and moving parts, and respect the minimum bend radius of approx 25 mm for the 6 mm OD tube. After the first greasing, confirm grease appears at the bearing.
What Is Supplied
Each assembly includes:
- SS316 threaded inlet, M6 x 1.0, M8 x 1.25, or 1/8″ NPT (BSP and other forms on request)
- PA12 or PU tube, 4 mm, 6 mm, or 8 mm OD, in 200 mm, 500 mm, or 800 mm standard lengths
- DIN 71412 hydraulic-type outlet nipple, or hose barb to specification
Honest Limitations
- The tube limits the assembly to -40°C to +80°C even though the SS316 inlet is rated to +200°C; keep the line off hot surfaces.
- A long, small-OD tube increases flow resistance and greasing time; manual greasing is not recommended beyond 1,000 mm.
- The plastic tube can be damaged by sharp edges, abrasion, and moving parts, so clamping and clean routing are part of the installation.
If dimensions or thread are uncertain, ask our team to confirm the thread and tube combination before ordering.
Frequently Asked Questions
When should I choose a flexible nipple extension?
When the point sits behind a guard, inside a housing, or around an obstruction a straight coupler cannot clear; if it already lines up directly, a rigid extension is simpler.
Which inlet thread should I order?
Measure the existing thread first. Standard inlets are M6 x 1.0, M8 x 1.25, and 1/8″ NPT; confirm the thread form and sealing arrangement when ordering.
What is the longest extension I can use?
Standard lengths are 200 mm, 500 mm, and 800 mm; 1,000 mm is the recommended limit for manual grease guns, as longer tubes add flow resistance.
Will a long, thin tube make greasing harder?
Yes. A long, small-OD tube increases resistance, so each stroke delivers grease more slowly; the 8 mm OD tube or a shorter run reduces it.
Which tube OD should I choose?
4 mm suits light-duty points in tight spaces, 6 mm is the general-purpose choice, and 8 mm suits larger grease volumes or longer runs.
What fitting is on the outlet end?
A DIN 71412 hydraulic-type grease nipple, so a manual coupler with an 8 – 11 mm jaw connects directly; hose barb outlets are available to specification.
Can it be used on an automatic lubrication system?
Yes, provided the tube pressure rating and metering arrangement are checked first; pump output, metering device, and tube diameter must match the intended dose.
How should the tube be secured?
Clamp it at approximately 300 mm intervals, clear of sharp edges, hot surfaces, and moving parts.
How often should the extension be inspected?
There is no fixed interval; check periodically for abrasion, hardening, kinks, and leakage. For a new routing, send us the grease point details and we will confirm a tube.
Who supplies this nipple extension?
IsoHiTech Lubrication Systems supplies the assembly with the SS316 inlet, PA12 or PU tube, and DIN 71412 outlet described above. The company was founded in 2023, engineering since 2006, and product questions can be sent to inquiry@isohitech.com.
