Tesco Steel & Engineering manufactures SAE J518 hydraulic flanges — Code 61 (3000 PSI) and Code 62 (6000 PSI) series, in both mono (single-piece) and split (4-bolt) configurations. Engineered for high-pressure hydraulic pump, motor, valve, and cylinder port connections. SS 316, Duplex, Carbon Steel, Inconel, Monel. Size 3/8" to 5" NB. 34–420 bar. ISO 9001:2015 certified. Made in India.
TES-LOK SAE J518 Flange
SAE Mono Flange (Single-Piece)
SAE Blind Mono Flange
SAE flanges are the dominant high-pressure connection method in mobile hydraulics, industrial hydraulic power units, and heavy machinery — they handle far higher pressures than threaded connections, resist vibration loosening, and allow connection/disconnection without rotating the pipe or hose. Tesco Steel & Engineering manufactures SAE flanges in mono (one-piece welded or threaded) and split (two-half clamp) configurations across the full material range.
| Criterion | Code 61 (Standard Pressure) | Code 62 (High Pressure) |
|---|---|---|
| SAE / ISO standard | SAE J518 Code 61 / ISO 6162-1 | SAE J518 Code 62 / ISO 6162-2 |
| Pressure rating | 3000–5000 PSI (207–345 bar) — size dependent | 6000 PSI (420 bar) — all sizes |
| Flange head diameter | Larger flange head for same port size | Smaller, thicker flange head |
| Bolt size | Smaller bolts (e.g. M8 / M10) | Larger bolts (e.g. M10 / M12) |
| Bolt spacing | Wider bolt-hole spacing | Closer bolt-hole spacing |
| Interchangeability | Not interchangeable with Code 62 — different bolt patterns | Not interchangeable with Code 61 — verify port code before ordering |
| Typical use | Hydraulic pump suction/return, medium-pressure circuits, mobile equipment | High-pressure hydraulic pump outlet, press circuits, heavy industrial hydraulics |
| Feature | Mono Flange (Single-Piece) | Split Flange (Two-Half Clamp) |
|---|---|---|
| Construction | One-piece flange head with the pipe connection (threaded / weld) integral or welded | Two semi-circular clamp halves bolted over a flange head / weld collar |
| Assembly | Flange bolts directly to the port; pipe connection on the back | The two clamp halves wrap around the captive weld-collar or flanged tube end |
| Bolt count | 4 bolts (or 2 for small split) | 4 bolts (2 per half) |
| Best for | Permanent connections; threaded or welded pipe-end to port | Field-serviceable connections; allows pipe to be removed without disconnecting from port |
| Sealing | O-ring in port face groove or flange groove | O-ring in flange head groove |
| Connection Type | Description | Best Application |
|---|---|---|
| Threaded NPT | Female NPT thread on the flange back for pipe-thread connection | Threaded hydraulic pipe systems; field adaptation |
| Threaded BSPP | Female BSPP (G) parallel thread with O-ring or bonded seal | European hydraulic systems with BSPP-threaded piping |
| Socket Weld (Weld-In) | Counter-bore socket — pipe slips in and is fillet welded | Welded hydraulic pipe systems; permanent connections |
| Butt Weld (Weld-On) | Bevelled or plain weld end butted to pipe and full-penetration welded | High-integrity welded hydraulic lines; large bore |
| Blind (Mono Blind) | No bore — solid flange head to blank off an unused SAE port | Capping unused pump / valve ports; pressure testing |
| Parameter | Details |
|---|---|
| Brand | TES-LOK (Tesco Steel & Engineering) |
| Size Range | 3/8" to 5" NB |
| Pressure Series | Code 61 — 3000 PSI | Code 62 — 6000 PSI |
| Working Pressure | 34 bar to 420 bar (depending on size and code) |
| Configuration | Mono Flange (single-piece) | Split Flange (two-half clamp) | Blind Mono Flange |
| Connection Types | Threaded NPT, Threaded BSPP, Socket Weld (Weld-In), Butt Weld (Weld-On), Blind |
| Standards | SAE J518 | ISO 6162-1 (Code 61) | ISO 6162-2 (Code 62) | ISO 6164 (high-pressure 4-bolt) |
| O-Ring Material | NBR (standard), Viton (FKM), EPDM — by hydraulic fluid type |
| Certifications | ISO 9001:2015 | EN 10204 3.1 MTC | PMI (XRF) on request | Hydrostatic test cert |
| Material Family | Grades / ASTM Spec |
|---|---|
| Stainless Steel SAE Flanges | ASTM A182 F304 / 304H / 304L / 316 / 316H / 316L / 316Ti, 309, 310, 317L, 321, 347, 904L |
| Duplex & Super Duplex SAE Flanges | ASTM A182 F51 (2205), F53 (2507), F55 (Zeron 100) |
| Alloy Steel SAE Flanges | ASTM A182 F5, F9, F11, F21, F22, F91 |
| Carbon Steel SAE Flanges | ASTM A105 (standard hydraulic flange material) |
| Low-Temp Carbon Steel (LTCS) | ASTM A350 LF2 — cryogenic / low-temperature service |
| Copper-Nickel SAE Flanges | C70600 (90/10), C71500 (70/30), C71640 |
| Nickel SAE Flanges | UNS N02200, UNS N02201 |
| Monel SAE Flanges | UNS N04400, UNS N05500, Alloy 20 |
| Inconel SAE Flanges | UNS N06600, N06601, N06625, N08800, N08810, N08825 |
| Hastelloy SAE Flanges | UNS N10276, N06022, N10665, N06455 |
| Titanium SAE Flanges | Gr. 1, Gr. 2, Gr. 3, DTH 3.7035, DTH 3.7055 |
Download the full TES-LOK SAE flange dimension tables for the 3000 PSI (Code 61) and 6000 PSI (Code 62) series — bolt circle, flange head diameter, bolt size, and bore dimensions for each NB size:
📄 3000 PSI SAE Flange Dimensions (PDF) 📄 6000 PSI SAE Flange Dimensions (PDF) 📄 Split Flange Dimensions (PDF) 📄 Blind Mono Flange Dimensions (PDF)| O-Ring Material | Temperature Range | Compatible Hydraulic Fluid | Avoid With |
|---|---|---|---|
| NBR (Nitrile) — Standard | −40°C to +100°C | Mineral oil hydraulic fluids (ISO HM / HV), diesel | Phosphate ester, skydrol, hot water |
| Viton (FKM) | −20°C to +200°C | High-temperature mineral oils, fire-resistant HFD fluids | Skydrol (phosphate ester), hot water/steam |
| EPDM | −40°C to +150°C | Phosphate ester (Skydrol) fire-resistant fluids, water-glycol (HFC) | Mineral oils, petroleum-based fluids |
Flange head diameter, bolt circle, bolt hole size, and O-ring groove dimensions are machined to SAE J518 / ISO 6162 tolerances for both Code 61 and Code 62 series — ensuring direct interchangeability with hydraulic pumps, motors, and valves from any OEM worldwide.
From standard Carbon Steel A105 (most common hydraulic flange material) to SS 316, Duplex, Inconel, Monel, and Hastelloy for corrosive and marine hydraulic systems. Single-source supply across the full alloy spectrum with EN 10204 3.1 MTC.
Complete SAE flange family — mono (single-piece), split (4-bolt clamp), and blind (port-capping) — all to the same dimensional standard, with threaded, socket-weld, and butt-weld pipe-end options. One supplier for the entire hydraulic flange bill of material.
Code 62 (6000 PSI / 420 bar) flanges manufactured for high-pressure hydraulic press circuits, heavy machinery, and mobile equipment outlet ports — where threaded connections cannot reliably hold pressure and vibration resistance is critical.
Full dimensional data for 3000 PSI and 6000 PSI series available as downloadable PDF charts — bolt circle, flange OD, bolt size, and bore for every NB size. Specify and verify before ordering, or share with your design team for hydraulic circuit layout.
SAE flanges are manufactured on the same CNC machining centres and to the same QA/QC discipline that govern our full range of ASME, DIN, and EN flanges. ISO 9001:2015 certified, with material traceability and hydrostatic testing on every batch.
| Industry | Typical Use Point | Why SAE Flange Preferred |
|---|---|---|
| Mobile & Construction Equipment | Excavator, loader, crane hydraulic pump and motor port connections | 4-bolt clamp resists vibration and shock; high pressure with no thread loosening |
| Industrial Hydraulics | Hydraulic power unit pump outlet, manifold block port connections, press circuits | Code 62 handles 6000 PSI press circuits; compact connection where threaded fittings fail |
| Marine & Offshore | Deck machinery hydraulics, winch and crane circuits, steering gear hydraulics | SS 316 / Duplex SAE flange resists marine corrosion; bolted joint reliable under wave-induced vibration |
| Oil & Gas | BOP hydraulic control, drilling rig hydraulic circuits, top-drive hydraulics | High-pressure Code 62; corrosion-resistant alloys for offshore environment |
| Steel & Metals | Rolling mill hydraulics, continuous casting hydraulic systems | Heavy-duty connection withstands high-pressure cyclic loading in steel plant hydraulics |
| Mining | Heavy haul truck, shovel, and drill rig hydraulic systems | 4-bolt SAE flange survives extreme shock and vibration in mining equipment |
| Plastics & Injection Moulding | Injection moulding machine hydraulic clamp and injection circuits | Code 62 high-pressure connection for the high-pressure injection and clamping hydraulics |
| Wind Energy | Wind turbine pitch and yaw hydraulic systems, brake hydraulics | Vibration-resistant flange connection in nacelle hydraulic circuits subject to constant motion |
Q1. What is the difference between SAE Code 61 and Code 62 flanges?
Both are 4-bolt SAE J518 hydraulic flanges, but Code 61 is the standard-pressure series (3000–5000 PSI / 207–345 bar) and Code 62 is the high-pressure series (6000 PSI / 420 bar). For the same nominal port size, Code 62 has a smaller, thicker flange head, larger bolts, and closer bolt-hole spacing to handle the higher pressure. They are not interchangeable — a Code 61 flange will not fit a Code 62 port and vice versa. Always confirm the code stamped on the equipment port before ordering.
Q2. What is the difference between a mono flange and a split flange in SAE connections?
A mono flange is a single-piece flange head where the pipe connection (threaded, socket weld, or butt weld) is integral or welded to one body. A split flange uses two semi-circular clamp halves that bolt over a flange head or weld collar on the pipe. The split design allows the pipe to be removed without disconnecting from the port (and is easier to install in tight spaces); the mono design is a simpler, single-piece permanent connection. Both seal with an O-ring and use 4 bolts.
Q3. What standard governs SAE flanges?
SAE flanges are governed by SAE J518 "Hydraulic Flanged Tube, Pipe, and Hose Connections, Four-Bolt Split Flange Type." The equivalent international standard is ISO 6162-1 (Code 61) and ISO 6162-2 (Code 62). A related higher-pressure 4-bolt standard is ISO 6164, used for very high pressure (up to 420+ bar) in some European hydraulic systems. TES-LOK manufactures to all these standards.
Q4. What pressure can an SAE flange handle?
Code 61 flanges are rated 3000–5000 PSI (207–345 bar) depending on size — smaller sizes carry higher pressure. Code 62 flanges are rated 6000 PSI (420 bar) across all sizes. The actual working pressure for a specific size is given in the dimension charts. For pressures above 420 bar, ISO 6164 or special heavy-duty flange designs are required — contact TES-LOK for high-pressure special applications.
Q5. Why are SAE flanges preferred over threaded connections in hydraulics?
SAE flanges handle far higher pressure than threaded fittings, do not loosen under the vibration and pressure pulsation common in hydraulic systems, and can be connected/disconnected without rotating the pipe or hose (important where space is tight). The O-ring face seal is more reliable than thread sealing, and the 4-bolt clamp distributes the load evenly. Above about 1" NB and 3000 PSI, SAE flanges are the standard hydraulic connection method worldwide.
Q6. What O-ring material should I use for Skydrol (phosphate ester) hydraulic fluid?
Use EPDM. Skydrol and other phosphate ester fire-resistant hydraulic fluids attack NBR (nitrile) and Viton (FKM) O-rings, causing rapid swelling and seal failure. EPDM is compatible with phosphate ester fluids. Conversely, EPDM must NOT be used with mineral-oil hydraulic fluids — for those, use NBR (standard) or Viton (high temperature). Always match the O-ring elastomer to the specific hydraulic fluid.
Q7. Can TES-LOK supply SAE flanges in stainless steel or duplex for marine hydraulics?
Yes. SAE flanges are available in SS 304, SS 316 / 316L, Duplex 2205, and Super Duplex 2507 for marine, offshore, and corrosive-environment hydraulic systems. These are supplied with EN 10204 3.1 material test certificates and PMI on request. SS 316 and Duplex resist the chloride-induced corrosion that attacks standard Carbon Steel flanges in marine atmospheres and seawater-adjacent installations.
Q8. Do you provide SAE flange dimension charts?
Yes. Full dimension charts for the 3000 PSI (Code 61) and 6000 PSI (Code 62) series, including split and blind flange dimensions, are available as downloadable PDF documents on this page. These give bolt circle diameter, flange head OD, bolt size, bolt-hole spacing, and bore dimensions for every NB size. For any size or configuration not in the standard charts, contact our technical team for custom dimensional data.