Visual fluid level indicators for hydraulic reservoirs, mounted on two banjo bolts. Epoxy-coated steel housing, polyamide sight tube, scale plate — and they can carry a thermometer, thermo switch or PT100 sensor in the same bolt, so level and temperature read from one hole.
State bolt centre distance, bolt size, seal material and temperature option — quotes within 2 working hours.
| Type | STAUFF SNA — banjo bolt mounting |
|---|---|
| Standard sizes | 76 · 127 · 150 · 176 · 254 · 305 mm |
| Specials | To 950 mm (1 mm tolerance) |
| Tank pressure | Maximum 2 bar / 29 psi |
| Temperature | −30…+80 °C (−40 °C on request) |
| Housing | Steel St 12, black epoxy — alu/stainless optional |
| Seals | NBR standard · FPM (Viton) · EPDM |
| Protection | IP65 standard · IP67 on request |
The size table, drill sizes per bolt, thermometer options and the eight-field order code are on this page, as printed in the catalogue.
| At a glance | SNA 127 | SNA 254 | SNA 305 |
|---|---|---|---|
| Bolt centres | 127 mm | 254 mm | 305 mm |
| Visible | 76 mm | 192 mm | 244 mm |
| Display | Undivided | 2 sections | 3 sections |
| Size | Bolt centres L2 | Overall L1 | Visible L3 | Display |
|---|---|---|---|---|
| SNA 076 | 76 mm / 2.99″ | 108 mm | 31 mm | Undivided |
| SNA 127 | 127 mm / 5.00″ | 159 mm | 76 mm | Undivided |
| SNA 150 | 150 mm / 5.91″ | 182 mm | 99 mm | Undivided |
| SNA 176 | 176 mm / 6.93″ | 208 mm | 124 mm | Undivided |
| SNA 254 | 254 mm / 10.00″ | 285 mm | 192 mm | 2 sections with strut |
| SNA 305 | 305 mm / 12.00″ | 336 mm | 244 mm | 3 sections with struts |
The visible length is always much shorter than the bolt centres — on the SNA 076 it is 31 mm out of 76 mm. If you need to see a particular band of level, take the figure from the Visible L3 column, not from the type name. Dimensions common to all models: width 45 mm, depth 34.5 mm, C max 8 mm, D 27 mm, E 43.5 mm.
Banjo bolts and drill sizes
| Bolt type | Clearance hole | Status |
|---|---|---|
| M12 | Ø13.0 mm (0.51″) | Standard |
| M10 | Ø10.5 mm (0.41″) | Optional |
| 1/2″-13 UNC | Ø13.5 mm (0.53″) | Optional |
| 1/2″-20 UNF | Ø13.5 mm (0.53″) | Optional |
| 1/2″-28 UNEF | Ø13.5 mm (0.53″) | Optional |
Bolt centre tolerance: ±0.20 mm per DIN ISO 2768-f, and deburring is required before installation. Recommended tightening torque 8 N·m / 5.9 ft·lb — deliberately low; tighter damages the housing and the tube. Bolts available in steel or stainless.
| Component | Standard material | Options |
|---|---|---|
| Housing | Steel St 12, black epoxy | Aluminium, stainless steel |
| Sight tube & plugs | Polyamide (PA) | Special materials for non-standard fluids |
| Sealings | NBR (Buna-N) | FPM (Viton), EPDM |
| Scale plate | PVC | Aluminium (for sizes >670 mm) |
| Floating element | Coloured polyamide | Replaces the scale plate above 670 mm |
| Banjo bolts | Steel | Stainless |
Fluids: standard builds are for mineral and petroleum-based hydraulic fluids (HL and HLP). Bio-degradable fluids, diesel oils and gasolines need special sight tube materials — state the fluid type when ordering, not after the tube has clouded.
| Option | Range | What it is |
|---|---|---|
| Capillary thermometer (codes T, TB) | To +80 °C / +180 °F | A thermometer strip printed onto the scale plate — red or blue |
| Dial thermometer, 200 mm probe (T1C, T1CF) | To +100 °C / +200 °F | Celsius or dual scale — probe projects 165.5 mm |
| Dial thermometer, 300 mm probe (T2C, T2CF) | To +100 °C / +200 °F | Celsius or dual scale — probe projects 265.5 mm |
| Thermo switch (O, OD, C, CD) | Trips at +60, +70, +80, +90 °C | A contact that opens or closes at the set temperature |
| PT100 sensor | Continuous measurement | Platinum resistance sensor on an M12 connector |
⚠ Thermo switches and PT100 sensors are M12 only. Both are built into the banjo bolt, and STAUFF only offers that in the M12 size — so if you need a switch, the bolt size is already decided. Break contact (normally closed) opens as temperature rises and is the fail-safe choice for an alarm; make contact closes as temperature rises and is what drives a fan.
Example: SNA 127 B-S-0-12-O-60
| Field | Options |
|---|---|
| 1 — Type | SNA |
| 2 — Nominal size | 076, 127, 150, 176, 254, 305 |
| 3 — Sealing material | B NBR · V FPM (Viton) |
| 4 — Scale plate | S STAUFF logo · N neutral · X custom |
| 5 — Thermometer | 0 none · T, TB, T1C, T2C, T1CF, T2CF |
| 6 — Banjo bolt size | 12 M12 · 10 M10 · U1, U2, U3 (1/2″ variants) |
| 7 — Switch / sensor | - none · O, OD, C, CD, PT100 |
| 8 — Switch temperature | 60, 70, 80, 90 — only with a switch |
Within ±0.20 mm of nominal. Two holes at the wrong pitch cannot be corrected with a spanner — the one fatal mistake on this product.
Swarf left on the hole edge cuts the seal as the bolt is tightened.
The figure is deliberately low — this is plastic and sheet, not a steel flange.
Never use it as a step or a handhold. Clean the outside only, and avoid solvents that attack polyamide or PVC.
If the sight tube goes cloudy or crazes, that is not normal wear — it usually means the fluid or the UV exposure is outside what the standard polyamide tube is designed for. What is needed is a special tube material, not another standard replacement.
Full dimensions and part numbers are in the catalogue, as printed; stock and price are not — send the list and we confirm both.
A maximum of 2 bar / 29 psi. The limit comes from the polyamide sight tube — this is not a device for pressure vessels.
Order by the bolt centre distance in millimetres — that is the figure in the type name. The visible sight-tube length is always shorter: an SNA 127 has 127 mm bolt centres but only 76 mm of visible tube.
Yes — specials are made to a maximum nominal size of 950 mm / 37.4″, held to a 1 mm tolerance. Above 450 mm dampening clips are added; above 670 mm the scale plate is replaced by a floating element.
Yes — a capillary strip on the scale plate (to +80 °C), a dial thermometer with a 200 or 300 mm probe (to +100 °C), a thermo switch, or a PT100 sensor. One hole in the tank, level and temperature together.
Because the switch and the PT100 are built into the banjo bolt, and STAUFF only offers that in the M12 size. If you need a switch, the bolt size is already decided.
Break contact (normally closed) opens as the temperature rises — the fail-safe choice for an alarm, because a broken wire gives the same result as an alarm condition. Make contact closes as temperature rises, and that is what drives a fan.
Standard builds handle mineral and petroleum based hydraulic fluids (HL and HLP). Bio-degradable fluids, diesel oils and gasolines need special sight tube materials — state the fluid type when ordering.
8 N·m / 5.9 ft·lb, and it is deliberately low. Tightening beyond it damages the housing and the sight tube.
13.0 mm for M12, 10.5 mm for M10, and 13.5 mm for the 1/2″ UNC, UNF and UNEF threads. Centres must be within ±0.20 mm — two holes at the wrong pitch is the one mistake on this product that cannot be corrected with a spanner.
−30 to +80 °C as standard. Special low-temperature versions to −40 °C are available on request.
IP65 as standard — dust tight and protected against water jets — with IP67 available on request.
No. Crazing or discolouration usually means the fluid or the UV exposure is outside what the standard polyamide tube is designed for. What is needed is a special tube material, not another standard replacement.
Our running items are the 127 mm and 254 mm sizes with M12 bolts, NBR seals and the standard scale plate — held in our regional warehouses in Singapore and Malaysia, out within 24 hours of your PO. Special builds are made to order.
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