45° Long Radius Elbow Dimensions
The 45° long radius elbow makes a half turn on the same 1.5D centerline radius as its 90° counterpart. It is the fitting that lets a line change direction gradually: offsetting around an obstruction, easing into a rack, or splitting the difference on a run that does not turn square.
Two 45s versus one 90.
A pair of 45° elbows creates a dogleg offset with less pressure loss and a gentler flow path than a square turn, which is why offsets around structural steel and equipment are usually built this way.
Reading the A dimension.
A is measured from the centerline intersection to the face of either end. Unlike the 90° elbow it is not simply 1.5 × NPS, because the geometry of the half turn changes the number, so take it from the table rather than calculating it.
How To Read These Dimensions
ASME B16.9 dimensions the 45 degree elbow on the same 1.5D centerline radius as the 90, but the half turn gives it its own center-to-end. That is the A column below, and it is a tabulated figure rather than a multiple of the nominal size.
- O.D.
- Outside diameterOutside diameter at the welding end, matching the pipe it welds to.
- I.D.
- Inside diameterBore through the fitting, set by the wall thickness.
- T
- Wall thicknessNominal wall at the welding end, matched to the pipe schedule.
- A
- Center to endFrom the intersection of the centerlines to the welding face on the half turn. It is not a simple multiple of the nominal size, so read it from the table.
121 sizes across 6 schedules · dimensions in inches, weights in pounds · ASME B16.9
Schedule STD
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End A | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.622 | 0.109 | 0.62 | 40 | 0.09 |
| ¾ | 1.05 | 0.824 | 0.113 | 0.75 | 40 | 0.10 |
| 1 | 1.32 | 1.049 | 0.133 | 0.88 | 40 | 0.22 |
| 1¼ | 1.66 | 1.380 | 0.140 | 1.00 | 40 | 0.33 |
| 1½ | 1.90 | 1.610 | 0.145 | 1.12 | 40 | 0.43 |
| 2 | 2.38 | 2.067 | 0.154 | 1.38 | 40 | 0.85 |
| 2½ | 2.88 | 2.469 | 0.203 | 1.75 | 40 | 1.70 |
| 3 | 3.50 | 3.068 | 0.216 | 2.00 | 40 | 2.50 |
| 3½ | 4.00 | 3.548 | 0.226 | 2.25 | 40 | 3.40 |
| 4 | 4.50 | 4.026 | 0.237 | 2.50 | 40 | 4.50 |
| 5 | 5.56 | 5.047 | 0.258 | 3.12 | 40 | 7.50 |
| 6 | 6.62 | 6.065 | 0.280 | 3.75 | 40 | 11.70 |
| 8 | 8.62 | 7.981 | 0.322 | 5.00 | 40 | 23.30 |
| 10 | 10.75 | 10.020 | 0.365 | 6.25 | 40 | 40.90 |
| 12 | 12.75 | 12.000 | 0.375 | 7.50 | * | 61.40 |
| 14 | 14.00 | 13.250 | 0.375 | 8.75 | 30 | 78.10 |
| 16 | 16.00 | 15.250 | 0.375 | 10.00 | 30 | 101.00 |
| 18 | 18.00 | 17.250 | 0.375 | 11.25 | * | 128.00 |
| 20 | 20.00 | 19.250 | 0.375 | 12.50 | 20 | 159.00 |
| 24 | 24.00 | 23.250 | 0.375 | 15.00 | 20 | 231.00 |
| 30 | 30.00 | 29.250 | 0.375 | 18.50 | * | 358.00 |
| 36 | 36.00 | 35.250 | 0.375 | 22.25 | * | 518.00 |
| 42 | 42.00 | 41.250 | 0.375 | 26.00 | * | 707.00 |
| 48 | 48.00 | 47.250 | 0.375 | 29.88 | * | 1000.00 |
Schedule XS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End A | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.546 | 0.147 | 0.62 | 80 | 0.15 |
| ¾ | 1.05 | 0.742 | 0.154 | 0.75 | 80 | 0.16 |
| 1 | 1.32 | 0.957 | 0.179 | 0.88 | 80 | 0.28 |
| 1¼ | 1.66 | 1.278 | 0.191 | 1.00 | 80 | 0.45 |
| 1½ | 1.90 | 1.500 | 0.200 | 1.12 | 80 | 0.61 |
| 2 | 2.38 | 1.939 | 0.218 | 1.38 | 80 | 1.20 |
| 2½ | 2.88 | 2.323 | 0.276 | 1.75 | 80 | 2.00 |
| 3 | 3.50 | 2.900 | 0.300 | 2.00 | 80 | 3.30 |
| 3½ | 4.00 | 3.364 | 0.318 | 2.25 | 80 | 4.50 |
| 4 | 4.50 | 3.826 | 0.337 | 2.50 | 80 | 6.20 |
| 5 | 5.56 | 4.813 | 0.375 | 3.12 | 80 | 10.50 |
| 6 | 6.62 | 5.761 | 0.432 | 3.75 | 80 | 17.00 |
| 8 | 8.62 | 7.625 | 0.500 | 5.00 | 80 | 34.30 |
| 10 | 10.75 | 9.750 | 0.500 | 6.25 | 60 | 53.50 |
| 12 | 12.75 | 11.750 | 0.500 | 7.50 | * | 77.60 |
| 14 | 14.00 | 13.000 | 0.500 | 8.75 | * | 100.00 |
| 16 | 16.00 | 15.000 | 0.500 | 10.00 | 40 | 134.00 |
| 18 | 18.00 | 17.000 | 0.500 | 11.25 | * | 170.00 |
| 20 | 20.00 | 19.000 | 0.500 | 12.50 | 30 | 209.00 |
| 24 | 24.00 | 23.000 | 0.500 | 15.00 | * | 302.00 |
| 30 | 30.00 | 29.000 | 0.500 | 18.50 | 20 | 475.10 |
| 36 | 36.00 | 35.000 | 0.500 | 22.25 | 20 | 686.10 |
| 42 | 42.00 | 41.000 | 0.500 | 26.00 | * | 936.10 |
| 48 | 48.00 | 47.000 | 0.500 | 29.88 | * | 1250.00 |
Schedule 40
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End A | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.622 | 0.109 | 0.62 | 40 | 0.09 |
| ¾ | 1.05 | 0.824 | 0.113 | 0.75 | 40 | 0.10 |
| 1 | 1.32 | 1.054 | 0.133 | 0.88 | 40 | 0.22 |
| 1¼ | 1.66 | 1.380 | 0.140 | 1.00 | 40 | 0.33 |
| 1½ | 1.90 | 1.610 | 0.145 | 1.12 | 40 | 0.43 |
| 2 | 2.38 | 2.072 | 0.154 | 1.38 | 40 | 0.85 |
| 2½ | 2.88 | 2.474 | 0.203 | 1.75 | 40 | 1.70 |
| 3 | 3.50 | 3.068 | 0.216 | 2.00 | 40 | 2.50 |
| 3½ | 4.00 | 3.548 | 0.226 | 2.25 | 40 | 3.40 |
| 4 | 4.50 | 4.026 | 0.237 | 2.50 | 40 | 4.50 |
| 5 | 5.56 | 5.044 | 0.258 | 3.12 | 40 | 7.50 |
| 6 | 6.62 | 6.060 | 0.280 | 3.75 | 40 | 11.70 |
| 8 | 8.62 | 7.976 | 0.322 | 5.00 | 40 | 23.30 |
| 10 | 10.75 | 10.020 | 0.365 | 6.25 | 40 | 40.90 |
| 12 | 12.75 | 11.938 | 0.406 | 7.50 | 40 | 65.00 |
| 14 | 14.00 | 13.124 | 0.438 | 8.75 | 40 | 80.00 |
| 16 | 16.00 | 15.000 | 0.500 | 10.00 | 40 | 105.00 |
| 18 | 18.00 | 16.876 | 0.562 | 11.25 | 40 | 130.00 |
| 20 | 20.00 | 18.812 | 0.594 | 12.50 | 40 | 165.00 |
| 24 | 24.00 | 22.624 | 0.688 | 15.00 | 40 | 235.00 |
Schedule 80
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End A | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.546 | 0.147 | 0.62 | 80 | 0.15 |
| ¾ | 1.05 | 0.742 | 0.154 | 0.75 | 80 | 0.16 |
| 1 | 1.32 | 0.962 | 0.179 | 0.88 | 80 | 0.28 |
| 1¼ | 1.66 | 1.278 | 0.191 | 1.00 | 80 | 0.45 |
| 1½ | 1.90 | 1.500 | 0.200 | 1.12 | 80 | 0.61 |
| 2 | 2.38 | 1.944 | 0.218 | 1.38 | 80 | 1.20 |
| 2½ | 2.88 | 2.328 | 0.276 | 1.75 | 80 | 2.00 |
| 3 | 3.50 | 2.900 | 0.300 | 2.00 | 80 | 3.30 |
| 3½ | 4.00 | 3.364 | 0.318 | 2.25 | 80 | 4.50 |
| 4 | 4.50 | 3.826 | 0.337 | 2.50 | 80 | 6.20 |
| 5 | 5.56 | 4.810 | 0.375 | 3.12 | 80 | 10.50 |
| 6 | 6.62 | 5.756 | 0.432 | 3.75 | 80 | 17.00 |
| 8 | 8.62 | 7.620 | 0.500 | 5.00 | 80 | 34.30 |
| 10 | 10.75 | 9.562 | 0.594 | 6.25 | 80 | 55.00 |
| 12 | 12.75 | 11.374 | 0.688 | 7.50 | 80 | 80.00 |
| 14 | 14.00 | 12.500 | 0.750 | 8.75 | 80 | 100.00 |
| 16 | 16.00 | 14.312 | 0.844 | 10.00 | 80 | 135.00 |
| 18 | 18.00 | 16.124 | 0.938 | 11.25 | 80 | 175.00 |
| 20 | 20.00 | 17.938 | 1.031 | 12.50 | 80 | 210.00 |
| 24 | 24.00 | 21.562 | 1.219 | 15.00 | 80 | 305.00 |
Schedule 160
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End A | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.464 | 0.188 | 0.62 | 160 | 1.80 |
| ¾ | 1.05 | 0.612 | 0.219 | 0.75 | 160 | 2.00 |
| 1 | 1.32 | 0.820 | 0.250 | 0.88 | 160 | 3.00 |
| 1¼ | 1.66 | 1.160 | 0.250 | 1.00 | 160 | 3.50 |
| 1½ | 1.90 | 1.338 | 0.281 | 1.12 | 160 | 3.70 |
| 2 | 2.38 | 1.692 | 0.344 | 1.38 | 160 | 5.00 |
| 2½ | 2.88 | 2.130 | 0.375 | 1.75 | 160 | 3.70 |
| 3 | 3.50 | 2.624 | 0.438 | 2.00 | 160 | 5.60 |
| 4 | 4.50 | 3.438 | 0.531 | 2.50 | 160 | 5.60 |
| 5 | 5.56 | 4.310 | 0.625 | 3.12 | 160 | 15.00 |
| 6 | 6.62 | 5.182 | 0.719 | 3.75 | 160 | 28.00 |
| 8 | 8.62 | 6.808 | 0.906 | 5.00 | 160 | 48.00 |
| 10 | 10.75 | 8.500 | 1.125 | 6.25 | 160 | 72.00 |
| 12 | 12.75 | 10.126 | 1.312 | 7.50 | 160 | 98.00 |
| 14 | 14.00 | 11.188 | 1.406 | 8.75 | 160 | 130.00 |
| 16 | 16.00 | 12.812 | 1.594 | 10.00 | 160 | 180.00 |
| 18 | 18.00 | 14.438 | 1.781 | 11.25 | 160 | 260.00 |
| 20 | 20.00 | 16.062 | 1.969 | 12.50 | 160 | 390.00 |
| 24 | 24.00 | 19.312 | 2.344 | 15.00 | 160 | 560.00 |
Schedule XXS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End A | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.252 | 0.294 | 0.62 | * | 1.80 |
| ¾ | 1.05 | 0.434 | 0.308 | 0.75 | * | 2.00 |
| 1 | 1.32 | 0.604 | 0.358 | 0.88 | * | 3.00 |
| 1¼ | 1.66 | 0.896 | 0.382 | 1.00 | * | 3.50 |
| 1½ | 1.90 | 1.100 | 0.400 | 1.12 | * | 3.70 |
| 2 | 2.38 | 1.508 | 0.436 | 1.38 | * | 5.00 |
| 2½ | 2.88 | 1.776 | 0.552 | 1.75 | * | 3.70 |
| 3 | 3.50 | 2.300 | 0.600 | 2.00 | * | 6.00 |
| 4 | 4.50 | 3.152 | 0.674 | 2.50 | * | 10.40 |
| 5 | 5.56 | 4.060 | 0.750 | 3.12 | * | 19.20 |
| 6 | 6.62 | 4.892 | 0.864 | 3.75 | * | 30.00 |
| 8 | 8.62 | 6.870 | 0.875 | 5.00 | * | 50.00 |
| 10 | 10.75 | 8.750 | 1.000 | 6.25 | 140 | 75.00 |
| 12 | 12.75 | 10.750 | 1.000 | 7.50 | 120 | 95.00 |
Materials We Supply
45° Long Radius Elbow to ASME B16.9 in the grades below. Tell us the service and we will confirm the right one.
| Material | Specification | Typical Service |
|---|---|---|
| Carbon Steel | ASTM A234 WPB / WPC | General process, steam, oil and gas gathering and utility lines |
| Low-Temp Carbon Steel | ASTM A420 WPL6 | Cold service to −50°F; LNG and northern pipeline work |
| Chrome-Moly Alloy | ASTM A234 WP11 / WP22 / WP91 | Elevated temperature; refinery heaters, power plant steam |
| Stainless Steel | ASTM A403 WP304/304L, WP316/316L | Corrosive service, chemical, food and beverage, water treatment |
| Duplex & Super Duplex | ASTM A815 UNS S31803 / S32750 | Chloride and seawater service, offshore, desalination |
Common Questions
What is a 45 degree elbow used for?
Changing direction by a half turn, typically to offset a line around an obstruction, to ease into or out of a pipe rack, or to follow a grade. Two 45° elbows in series create a smooth dogleg with less pressure loss than a pair of 90s.
What is the center-to-end of a 45 degree elbow?
It follows from the 1.5D bend radius and the half turn, and it is not 1.5 × NPS the way a 90° elbow is. Use the A column in the table above for the exact figure at your size and schedule.
Can I use two 45s instead of a 90?
Yes, and it is common practice for offsets. The flow path is gentler and the pressure loss lower than a single square turn, at the cost of one extra weld and more overall length.
