SAE Flanges

SAE Flanges are made to SAE J518/ISO 6162 standards and are designed for hydraulic applications.

SAE Flanges are also known as code 61 flanges or code 62 flanges. These 4 bolt flange connections are proven, leak-free connections, especially suitable for large size high pressure applications. Because of the o-ring seal design, SAE flanges provide connections with reasonable assemble torque range.



SAE Flanges are made of ferrous material. The materials usually used are carbon steel ST52.3 or stainless steel AISI SS316L.


Size Range:

SAE Code 61 flange are available in sizes ranging from 3/8"NB (DN 10) to 5"NB (DN 125). For SAE Code 62, flanges are available in sizes ranging from 3/8"NB (DN 10) to 3"NB (DN 80).


Connection Types:

SAE Flanges Connection types include socket welding (S/W) type, butt welding (B/W) type, British Standard Pipe Parallel thread (BSPP) and American National Pipe Tapered Thread (NPT) connection types. The most commonly used are socket welding type and butt welding type.


Yield Strength and Elongation at fracture:

For nominal size 13, the minimum yield strength is 220 MPa and minimum elongation at fracture is 3%. For all other sizes, the minimum yield strength is 415 MPa and minimum elongation at fracture is 3%.


O-Ring Seals:

The minimum o-rings seals quality is as per grade N of ISO 3601-3. Unless specified, the o-rings shall be of NBR material with hardness 90 +/- 5 IRHD measured as per ISO 48.

O-Ring Dimensions are as per below:


Pressure Rating:

In general, the working pressure for Code 61 SAE Flanges is up to 345 Bar. For Code 62 SAE Flanges, the maximum working pressure is up to 414 Bar.

Various Sizes have different working pressures and the table below illustrates the standard pressure.

Note that the pressure rating of connected equipment and SAE flanges may vary from each other. For example: if a valve connected to the flange has a lower maximum working pressure, the overall working pressure of the system will be based on the valve pressure. Therefore in a system, the item with the lowest pressure will be the maximum working pressure of the system.


Temperature Range:

The working pressure of the steel flanges is for when used between -40°C and +120°C.

The working pressure of stainless steel flanges is between -60°C and +50°C. Working Pressure for SAE Flanges made from stainless steel and used at elevated temperatures shall be reduced by:

4%: +50°C to < +100°C
11%: +100°C to < +200°C
20%: +200°C to < +250°C


Assembly Instruction of SAE Flange:

Step 1: Make sure sealing surfaces are clean and free of scratches and contamination.

Step 2: Place lock washers and bolts through the flanges.

Step 3: Hand tighten the bolts in a cross order. Do not tighten the bolts in a clock or anticlockwise manner.

Step 4: Tighten the bolts according to the torque chart.