Fitting Torque Specifications
To ensure leak-proof connections, hydraulic couplings must be tightened with precision. Applying torque values that exceed the maximum recommendation of your coupling manufacturer can distort or crack the fitting; conversely, if under-tightened,
a connection may still fail to produce an airtight seal. The tables below provide minimum and maximum recommended torques regulated by SAE J514 standards – these are designed for qualification testing only so make sure you set up production
environment based on specific recommendations from your supplier. Remember: when tightening any type of coupling it’s essential to focus on both accuracy and finesse!
Torque Adjustments
Proper torque readings are undeniably essential when using a crowfoot wrench with a torque wrench. To obtain the most reliable and accurate results, it’s imperative to factor in the distance ‘E’ that crooks exist between the center
of the drive socket and center of the crowfoot. To guarantee accuracy, all you have to do is add ‘E’ onto your decided setting. Following this simple process will guarantee that you can trust your reading and actually avoid over-tightening
any bolts
The following equation can be used to make these adjustments:
Actual Torque = (E + L) ÷ L (torque wrench reading) where:
L is in inches, feet or meters
E is in inches, feet or meters
Torque is in lb.-in., lb.-ft. or Newton-Meters
Example: Torque Wrench Reading = 45 lb.-ft.
E = 1.5″
L = 12″
Actual Torque = [(1.5 + 12) ÷ 12]* 45 = 50.6 lb.-ft.
Although indicated readings may appear to be accurate, this example highlights that actual torque is up to 10% higher. Our recommendation for achieving optimal performance: lubricate all O-rings prior to installing in flange heads
and grooves; This precaution reduces the risk of damaging the sealant during insertion and also has a potential maximum recommended torque reduction of 25%.
Coupling and Adapter Torque Recommendation
For 37° & 45° (Machined or Flared)
JIC
| Size | Steel | Brass | |||||||
| Ft. Lbs. | Newton-Meters | Ft. Lbs. | Newton-Meters | ||||||
| Dash | Inches | Min | Max | Min | Max | Min | Max | Min | Max |
| -4 | 1/4 | 10 | 11 | 13 | 15 | 5 | 6 | 6-3/4 | 9 |
| -5 | 5/16 | 13 | 15 | 18 | 20 | 7 | 9 | 10 | 13 |
| -6 | 3/8 | 17 | 19 | 23 | 26 | 12 | 15 | 17 | 20 |
| -8 | 1/2 | 34 | 38 | 47 | 52 | 20 | 24 | 27-2/3 | 33 |
| -10 | 5/8 | 50 | 56 | 69 | 76 | 34 | 40 | 46-1/3 | 55 |
| -12 | 3/4 | 70 | 78 | 96 | 106 | 53 | 60 | 72-1/3 | 82 |
| -16 | 1 | 94 | 104 | 127 | 141 | 74 | 82 | 100-1/2 | 111 |
| -20 | 1-1/4 | 124 | 138 | 169 | 188 | 75 | 83 | 101-1/2 | 113 |
| -24 | 1-1/2 | 156 | 173 | 212 | 235 | 79 | 87 | 107 | 118 |
| -32 | 2 | 219 | 243 | 296 | 329 | 158 | 175 | 214 | 237 |
For Flat-Face O-Ring Seal (Steel)
FACE SEAL
| Size | Newton-Meters | ||
| Dash | Inches | Min | Max |
| -4 | 1/4 | 14 | 16 |
| -6 | 3/8 | 24 | 27 |
| -8 | 1/2 | 43 | 54 |
| -10 | 5/8 | 60 | 75 |
| -12 | 3/4 | 90 | 110 |
| -14 | 7/8 | 90 | 110 |
| -16 | 1 | 125 | 240 |
| -20 | 1-1/4 | 170 | 190 |
| -24 | 1-1/2 | 200 | 245 |
For SAE O-Ring Boss (Steel)
O-RING BOSS
| Size |
Ft.Lbs. Working Pressures
4,000 psi (27.5 Mpa) and below
|
Newton-Meters Working Pressures 4,000 psi (27.5 Mpa) and below | Ft.Lbs. Working Pressures Above 4,000 psi (27.5 Mpa) |
Newton-Meters Working Pressures
Above 4,000 psi (27.5 Mpa)
|
|||||
| Dash | Inches | Min | Max | Min | Max | Min | Max | Min | Max |
| -3 | 3/16 | – | – | – | – | 8 | 10 | 11 | 13 |
| -4 | 1/4 | 14 | 16 | 20 | 22 | 14 | 16 | 20 | 22 |
| -5 | 5/16 | – | – | – | – | 18 | 20 | 24 | 27 |
| -6 | 3/8 | 24 | 26 | 33 | 35 | 24 | 26 | 33 | 35 |
| -8 | 1/2 | 37 | 44 | 50 | 60 | 50 | 60 | 68 | 78 |
| -10 | 5/8 | 50 | 60 | 68 | 81 | 72 | 80 | 98 | 110 |
| -12 | 3/4 | 75 | 83 | 101-1/2 | 113 | 125 | 135 | 170 | 183 |
| -14 | 7/8 | – | – | – | – | 160 | 180 | 215 | 245 |
| -16 | 1 | 111 | 125 | 150 | 170 | 200 | 220 | 270 | 300 |
| -20 | 1-1/4 | 133 | 152 | 180 | 206 | 210 | 280 | 285 | 380 |
| -24 | 1-1/2 | 156 | 184 | 212 | 250 | 270 | 360 | 370 | 490 |
For BSP 30° Inverted Cone
BSPP 60°
BRITISH
| Size | Ft.-Lbs. | Newton-Meters | |||
| Dash | Inches | Min | Max | Min | Max |
| -2 | 1/8 | 7 | 9 | 9 | 12 |
| -4 | 1/4 | 11 | 18 | 15 | 24 |
| -6 | 3/8 | 19 | 28 | 26 | 38 |
| -8 | 1/2 | 30 | 36 | 41 | 49 |
| -10 | 5/8 | 37 | 44 | 50 | 60 |
| -12 | 3/4 | 50 | 60 | 68 | 81 |
| -16 | 1 | 79 | 95 | 107 | 129 |
| -20 | 1-1/4 | 127 | 152 | 172 | 206 |
| -24 | 1-1/2 | 167 | 190 | 226 | 258 |
| -32 | 2 | 262 | 314 | 355 | 426 |
For DIN 2353 30° and Universal Inverted Cone
METRIC
| Size | Ft.-Lbs. | Newton-Metres | ||
| Light Series Tube O.D. (mm) | Min | Max | Min | Max |
| -6 | 7 | 15 | 10 | 20 |
| -8 | 15 | 26 | 20 | 35 |
| -10 | 18 | 30 | 25 | 40 |
| -12 | 22 | 33 | 30 | 45 |
| -14 | 26 | 37 | 35 | 50 |
| -15 | 30 | 52 | 40 | 70 |
| — | 30 | 52 | 40 | 70 |
| -18 | 44 | 74 | 60 | 100 |
| -22 | 59 | 89 | 80 | 120 |
| -28 | 74 | 111 | 100 | 150 |
| — | 74 | 162 | 150 | 220 |
| -35 | 133 | 184 | 180 | 250 |
| -42 | 148 | 221 | 200 | 300 |
Maximum Recommended Torque for Dry NPTF (Tapered) Pipe Threads
NPT
| Size | Ft-Lbs. | Newton-Meters |
| -2 | 20 | 25 |
DIN 24° Cone
HEAVY OIN
METRIC
| Tube O.D. (mm) | Ft.-Lbs. | Newton-Meters | |||
| Light Series | Heavy Series | Min | Max | Min | Max |
| -6 | – | 7 | 15 | 10 | 20 |
| -8 | – | 15 | 26 | 20 | 35 |
| -10 | -8 | 18 | 30 | 25 | 40 |
| -12 | -10 | 22 | 33 | 30 | 45 |
| -14 | -12 | 26 | 37 | 35 | 50 |
| -15 | -14 | 30 | 52 | 40 | 70 |
| – | -16 | 30 | 52 | 40 | 70 |
| -18 | – | 44 | 74 | 60 | 100 |
| -22 | -20 | 59 | 89 | 80 | 120 |
| -28 | -25 | 74 | 111 | 100 | 150 |
| – | -30 | 74 | 162 | 150 | 220 |
| -35 | – | 133 | 184 | 180 | 250 |
| -42 | -38 | 148 | 221 | 200 | 300 |
