A four-bolt flange conforming to SAE J518 and ISO 6162 — a leak-free connection for high pressure and larger sizes, where threads become impractical. Normalised forgings, supplied as complete sets: flat face, O-ring face, O-ring, washers and cap screws.
Send the size, code (61/62), end connection, material and quantity — a quote comes back within 2 working hours.
| Size | 1/2″ to 5″ · DN13–DN127 · dash −8 to −80 |
|---|---|
| Standard | SAE J518 · ISO 6162 |
| Series | 3000 (Code 61) · 6000 (Code 62) |
| Material | Carbon steel ST52.3 / S355 · stainless SS316L |
| Manufacture | Normalised forging, low-carbon grade |
| End connection | Threaded NPT · threaded BSPP · socket weld · butt weld |
| Configuration | SAE flange · split flange · flange adaptor · blind flange |
| Complete set | Flat face · O-ring face · O-ring · 4 washers & cap screws |
Full dimension tables per size are in the catalogues below, as printed — the pressure & torque tables for both codes are on this page.
| At a glance | Code 61 · 3000 | Code 62 · 6000 |
|---|---|---|
| Size | 1/2″–5″ | 1/2″–3″ |
| Working pressure | 34–345 bar | a flat 414 bar |
| Screws | M8–M16 · 32–295 Nm | M8–M30 · 32–650 Nm |
An SAE flange connects hydraulic components — pumps, motors, valves and pipe runs — with four bolts and an O-ring in a groove on the O-ring face. The joint can be broken for service without rotating the pipework, and remade many times: replace the O-ring, not the flange — the seal is the consumable, the flange is not. Used on heavy equipment, power packs, marine and industrial plant worldwide.
The bolt pattern (long side × short side, mm) is what separates the two codes — measure the bolt-hole centres on the long side, and that one dimension gives you the size and the code together. All figures as printed in the catalogues.
| Size | Code 61 · bolt pattern (mm) | Code 62 · bolt pattern (mm) |
|---|---|---|
| 1/2″ | 38.10 × 17.48 | 40.49 × 18.24 |
| 3/4″ | 47.63 × 22.23 | 50.80 × 23.80 |
| 1″ | 52.37 × 26.19 | 57.15 × 27.76 |
| 1¼″ | 58.72 × 30.18 | 66.68 × 31.75 |
| 1½″ | 69.85 × 35.71 | 79.38 × 36.50 |
| 2″ | 77.77 × 42.88 | 96.82 × 44.45 |
| 2½″ | 88.90 × 50.80 | 123.80 × 58.70 |
| 3″ | 106.38 × 61.93 | 152.40 × 71.40 |
| 3½″ | 120.65 × 69.85 | — |
| 4″ | 130.18 × 77.77 | — |
| 5″ | 152.40 × 92.08 | — |
3000 series · Code 61 — pressure, screws & torque metric screws, class 10.9
| Dash | Size | DN | Screw | Length | Min thread | Torque (Nm) | Max working pressure | Min burst |
|---|---|---|---|---|---|---|---|---|
| −8 | 1/2″ | 13 | M8 | 25 mm | 16 mm | 32 | 35 MPa / 350 bar | 140 MPa |
| −12 | 3/4″ | 19 | M10 | 30 mm | 18 mm | 70 | 35 MPa / 350 bar | 140 MPa |
| −16 | 1″ | 25 | M10 | 30 mm | 18 mm | 70 | 32 MPa / 320 bar | 128 MPa |
| −20 | 1¼″ | 32 | M10 | 30 mm | 18 mm | 70 | 28 MPa / 280 bar | 112 MPa |
| −24 | 1½″ | 38 | M12 | 35 mm | 23 mm | 130 | 21 MPa / 210 bar | 84 MPa |
| −32 | 2″ | 51 | M12 | 35 mm | 23 mm | 130 | 21 MPa / 210 bar | 84 MPa |
| −40 | 2½″ | 64 | M12 | 40 mm | 23 mm | 130 | 17.5 MPa / 175 bar | 70 MPa |
| −48 | 3″ | 76 | M16 | 50 mm | 30 mm | 295 | 16 MPa / 160 bar | 64 MPa |
| −56 | 3½″ | 89 | M16 | 50 mm | 30 mm | 295 | 3.5 MPa / 35 bar | 14 MPa |
| −64 | 4″ | 102 | M16 | 50 mm | 30 mm | 295 | 3.5 MPa / 35 bar | 14 MPa |
| −80 | 5″ | 127 | M16 | 55 mm | 30 mm | 295 | 3.5 MPa / 35 bar | 14 MPa |
6000 series · Code 62 — pressure, screws & torque metric screws, class 10.9
| Dash | Size | DN | Screw | Length | Min thread | Torque (Nm) | Max working pressure | Min burst |
|---|---|---|---|---|---|---|---|---|
| −8 | 1/2″ | 13 | M8 | 30 mm | 16 mm | 32 | 42 MPa / 420 bar | 168 MPa |
| −12 | 3/4″ | 19 | M10 | 35 mm | 18 mm | 70 | 42 MPa / 420 bar | 168 MPa |
| −16 | 1″ | 25 | M12 | 45 mm | 23 mm | 130 | 42 MPa / 420 bar | 168 MPa |
| −20 | 1¼″ | 32 | M12 | 45 mm | 23 mm | 130 | 42 MPa / 420 bar | 168 MPa |
| −24 | 1½″ | 38 | M16 | 55 mm | 27 mm | 295 | 42 MPa / 420 bar | 168 MPa |
| −32 | 2″ | 51 | M20 | 70 mm | 35 mm | 550 | 42 MPa / 420 bar | 168 MPa |
Torque at a glance: Code 61 — M8/32 Nm (1/2″) · M10/70 Nm (3/4″–1¼″) · M12/130 Nm (1½″–2½″) · M16/295 Nm (3″–5″). Code 62 — M8/32 · M10/70 · M12/130 (1″–1¼″) · M16/295 (1½″) · M20/550 (2″) · M24/550 (2½″) · M30/650 Nm (3″).
| Aspect | ST52.3 / S355 — carbon steel | SS316L — stainless |
|---|---|---|
| Strength | Higher tensile — the default | Lower, adequate for the ratings |
| Corrosion | Needs coating; galvanising available | Molybdenum austenitic; resists chlorides |
| Weldability | Good — butt/socket weld routine | Good; low carbon limits sensitisation |
| Standard bolts | Grade 8.8 yellow zinc | SS304 · SS316 on request |
| Chosen when | Pressure/stress govern | Marine, washdown, chemical plant |
O-ring size by flange size AS568
| Flange size | 1/2″ | 3/4″ | 1″ | 1¼″ | 1½″ | 2″ | 2½″ | 3″ | 3½″ | 4″ | 5″ |
|---|---|---|---|---|---|---|---|---|---|---|---|
| AS568 dash | 210 | 214 | 219 | 222 | 225 | 228 | 232 | 237 | 241 | 245 | 253 |
Seal materials — Viton 90 vs NBR 70/90
| Description | Viton 90 | NBR 70 / 90 |
|---|---|---|
| Equivalent | FKM | BUNA-N |
| Temperature range | −26 °C to +205 °C | −34 °C to +121 °C |
| Recommended applications | Petroleum oils & fluids · aromatic hydrocarbons · cold water · aliphatic hydrocarbons · fuels with methanol content · silicone grease & oils | Petroleum oils & fluids · diesel fuel & fuel oils · vegetable oil · cold water · silicone oil & grease · mineral oil & grease |
| Non-recommended | Low-molecular organic acids · glycol-based brake fluids · superheated steam · ammonia gas, amines, alkalis | Phosphate ester fluids · aromatic hydrocarbons · automotive brake fluid · strong acids |
The limiting part for fluid compatibility is the O-ring, not the metal — state the fluid on the enquiry and we select the compound.
On the long side — that one dimension gives you the size and the code together. Match it to the bolt-pattern table above.
An M marking indicates metric screws; look for the manufacturer’s name on the body too.
The AS568 dash number on the old O-ring is fixed per size — 228 means a 2″ flange.
Send a photo of the marking or your measurement on WhatsApp — we confirm the size and code.
For damage and contamination — grooves are leak paths.
Seat the O-ring in the groove, place the washers and cap screws.
Until the O-ring is seated evenly.
To the value for the size & code. Lightly torque every screw before applying the final value — work across the pattern, not around it, to avoid breaking a flange clamp.
Full dimension tables are in the catalogues, as printed. More catalogues in the catalogue library.
A four-bolt flange conforming to SAE J518 and ISO 6162, used to connect hydraulic components — a leak-free connection suited to high pressure and larger sizes, where threads become impractical.
Code 61 (3000 series) covers 1/2″–5″ at 34–345 bar. Code 62 (6000 series) covers 1/2″–3″ at a flat 414 bar, with more robust construction and slightly larger dimensions. They are not interchangeable — the bolt-hole spacing differs at every size (1/2″: 38.10 vs 40.49 mm), widening with size.
It depends on the size and the code — examples: 2″ Code 61 takes M12 at 130 Nm; 2″ Code 62 takes M20 at 550 Nm. The full tables for both codes are above. Torque compresses the O-ring and pulls the faces into contact.
NBR 70/90: −34…+121 °C, suits petroleum and diesel oils. Viton 90: −26…+205 °C, suits aromatic hydrocarbons. Neither works with glycol brake fluid or superheated steam. Sizes follow AS568 — see the table above.
Normalised forgings in carbon steel ST52.3/S355 (good weldability, structural strength) or stainless SS316L (corrosion resistance for harsh environments). Galvanised available on request.
Grade 8.8 yellow zinc as standard with carbon steel; SS304 with stainless. Grade 10.9 and SS316 available on request.
Four types: threaded NPT, threaded BSPP, socket weld and butt weld — plus split flange, flange adaptor and blind flange configurations.
Measure the bolt-hole centres on the long side — that one dimension gives you the size and the code together. Look for the M marking (metric screws) and the maker’s name, and read the AS568 dash number on the old O-ring.
Yes, if undamaged. Replace the O-ring rather than reusing it — the seal is the consumable, the flange is not.
Yes — 1/2″ to 5″ in both codes and both materials, as complete sets, in our regional warehouses in Singapore and Malaysia; goods leave within 24 hours of your PO. State the size, code, end connection, material and quantity via WhatsApp ★ Google reviews ▶ YouTube channel or the contact form — a quote comes back within 2 working hours.
See also all flanges, split flanges, blind flanges, JIS square flanges, and hydraulic steel tubes — or read this page in Bahasa Indonesia.
