Straight Tee Dimensions
A straight tee takes a branch off the run at 90°, with the branch the same size as the run. It is the standard way to split or combine flow in welded pipe, and after the elbow it is the most-used fitting on most jobs.
Run and branch.
The run is the through path; the branch is the outlet at right angles to it. On a straight tee all three ends share the same nominal size, so the C dimension (center to run end) and M dimension (center to branch end) come straight from the table.
Full-size branching without a weldolet.
Where the branch is the same size as the header, a tee is the cleaner answer than a fabricated branch connection: a factory-made fitting to ASME B16.9 with a known rating, rather than a reinforcement calculation you have to defend.
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 Center R | Center to End B | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.622 | 0.109 | 1.00 | 1.00 | 40 | 0.35 |
| ¾ | 1.05 | 0.824 | 0.113 | 1.12 | 1.12 | 40 | 0.50 |
| 1 | 1.32 | 1.049 | 0.133 | 1.50 | 1.50 | 40 | 0.75 |
| 1¼ | 1.66 | 1.380 | 0.140 | 1.88 | 1.88 | 40 | 1.30 |
| 1½ | 1.90 | 1.610 | 0.145 | 2.25 | 2.25 | 40 | 1.90 |
| 2 | 2.38 | 2.067 | 0.154 | 2.50 | 2.50 | 40 | 3.20 |
| 2½ | 2.88 | 2.469 | 0.203 | 3.00 | 3.00 | 40 | 5.80 |
| 3 | 3.50 | 3.068 | 0.216 | 3.38 | 3.38 | 40 | 7.20 |
| 3½ | 4.00 | 3.548 | 0.226 | 3.75 | 3.75 | 40 | 9.50 |
| 4 | 4.50 | 4.026 | 0.237 | 4.12 | 4.12 | 40 | 12.70 |
| 5 | 5.56 | 5.047 | 0.258 | 4.88 | 4.88 | 40 | 20.80 |
| 6 | 6.62 | 6.065 | 0.280 | 5.62 | 5.62 | 40 | 33.10 |
| 8 | 8.62 | 7.981 | 0.322 | 7.00 | 7.00 | 40 | 56.50 |
| 10 | 10.75 | 10.020 | 0.365 | 8.50 | 8.50 | 40 | 90.90 |
| 12 | 12.75 | 12.000 | 0.375 | 10.00 | 10.00 | * | 136.00 |
| 14 | 14.00 | 13.250 | 0.375 | 11.00 | 11.00 | 30 | 162.00 |
| 16 | 16.00 | 15.250 | 0.375 | 12.00 | 12.00 | 30 | 206.00 |
| 18 | 18.00 | 17.250 | 0.375 | 13.50 | 13.50 | * | 272.00 |
| 20 | 20.00 | 19.250 | 0.375 | 15.00 | 15.00 | 20 | 350.00 |
| 24 | 24.00 | 23.250 | 0.375 | 17.00 | 17.00 | 20 | 508.00 |
| 30 | 30.00 | 29.250 | 0.375 | 22.00 | 22.00 | * | 835.00 |
| 36 | 36.00 | 35.250 | 0.375 | 26.50 | 26.50 | * | 1294.00 |
| 42 | 42.00 | 41.250 | 0.375 | 30.00 | 28.00 | * | 1495.00 |
| 48 | 48.00 | 47.250 | 0.375 | 35.00 | 33.00 | * | 2300.00 |
Schedule XS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center R | Center to End B | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.546 | 0.147 | 1.00 | 1.00 | 80 | 0.37 |
| ¾ | 1.05 | 0.742 | 0.154 | 1.12 | 1.12 | 80 | 0.58 |
| 1 | 1.32 | 0.957 | 0.179 | 1.50 | 1.50 | 80 | 0.87 |
| 1¼ | 1.66 | 1.278 | 0.191 | 1.88 | 1.88 | 80 | 1.60 |
| 1½ | 1.90 | 1.500 | 0.200 | 2.25 | 2.25 | 80 | 2.30 |
| 2 | 2.38 | 1.939 | 0.218 | 2.50 | 2.50 | 80 | 3.90 |
| 2½ | 2.88 | 2.323 | 0.276 | 3.00 | 3.00 | 80 | 6.50 |
| 3 | 3.50 | 2.900 | 0.300 | 3.38 | 3.38 | 80 | 9.00 |
| 3½ | 4.00 | 3.364 | 0.318 | 3.75 | 3.75 | 80 | 12.20 |
| 4 | 4.50 | 3.826 | 0.337 | 4.12 | 4.12 | 80 | 16.20 |
| 5 | 5.56 | 4.813 | 0.375 | 4.88 | 4.88 | 80 | 26.60 |
| 6 | 6.62 | 5.761 | 0.432 | 5.62 | 5.62 | 80 | 41.80 |
| 8 | 8.62 | 7.625 | 0.500 | 7.00 | 7.00 | 80 | 76.20 |
| 10 | 10.75 | 9.750 | 0.500 | 8.50 | 8.50 | 60 | 115.00 |
| 12 | 12.75 | 11.750 | 0.500 | 10.00 | 10.00 | * | 169.00 |
| 14 | 14.00 | 13.000 | 0.500 | 11.00 | 11.00 | * | 237.00 |
| 16 | 16.00 | 15.000 | 0.500 | 12.00 | 12.00 | 40 | 284.00 |
| 18 | 18.00 | 17.000 | 0.500 | 13.50 | 13.50 | * | 353.00 |
| 20 | 20.00 | 19.000 | 0.500 | 15.00 | 15.00 | 30 | 442.00 |
| 24 | 24.00 | 23.000 | 0.500 | 17.00 | 17.00 | * | 625.00 |
| 30 | 30.00 | 29.000 | 0.500 | 22.00 | 22.00 | 20 | 1065.00 |
| 36 | 36.00 | 35.000 | 0.500 | 26.50 | 26.50 | 20 | 1610.00 |
| 42 | 42.00 | 41.000 | 0.500 | 30.00 | 28.00 | * | 1788.00 |
| 48 | 48.00 | 47.000 | 0.500 | 35.00 | 33.00 | * | 2300.00 |
Schedule 40
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center R | Center to End B | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.622 | 0.109 | 1.00 | 1.00 | 40 | 0.35 |
| ¾ | 1.05 | 0.824 | 0.113 | 1.12 | 1.12 | 40 | 0.50 |
| 1 | 1.32 | 1.054 | 0.133 | 1.50 | 1.50 | 40 | 0.75 |
| 1¼ | 1.66 | 1.380 | 0.140 | 1.88 | 1.88 | 40 | 1.30 |
| 1½ | 1.90 | 1.610 | 0.145 | 2.25 | 2.25 | 40 | 1.90 |
| 2 | 2.38 | 2.072 | 0.154 | 2.50 | 2.50 | 40 | 3.20 |
| 2½ | 2.88 | 2.474 | 0.203 | 3.00 | 3.00 | 40 | 5.80 |
| 3 | 3.50 | 3.068 | 0.216 | 3.38 | 3.38 | 40 | 7.20 |
| 3½ | 4.00 | 3.548 | 0.226 | 3.75 | 3.75 | 40 | 8.50 |
| 4 | 4.50 | 4.026 | 0.237 | 4.12 | 4.12 | 40 | 9.50 |
| 5 | 5.56 | 5.044 | 0.258 | 4.88 | 4.88 | 40 | 12.70 |
| 6 | 6.62 | 6.060 | 0.280 | 5.62 | 5.62 | 40 | 20.80 |
| 8 | 8.62 | 7.976 | 0.322 | 7.00 | 7.00 | 40 | 33.10 |
| 10 | 10.75 | 10.020 | 0.365 | 8.50 | 8.50 | 40 | 56.50 |
| 12 | 12.75 | 11.938 | 0.406 | 10.00 | 10.00 | 40 | 90.90 |
| 14 | 14.00 | 13.124 | 0.438 | 11.00 | 11.00 | 40 | 165.00 |
| 16 | 16.00 | 15.000 | 0.500 | 12.00 | 12.00 | 40 | 210.00 |
| 18 | 18.00 | 16.876 | 0.562 | 13.50 | 13.50 | 40 | 275.00 |
| 20 | 20.00 | 18.812 | 0.594 | 15.00 | 15.00 | 40 | 355.00 |
| 24 | 24.00 | 22.624 | 0.688 | 17.00 | 17.00 | 40 | 510.00 |
Schedule 80
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center R | Center to End B | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.546 | 0.147 | 1.00 | 1.00 | 80 | 0.37 |
| ¾ | 1.05 | 0.742 | 0.154 | 1.12 | 1.12 | 80 | 0.58 |
| 1 | 1.32 | 0.962 | 0.179 | 1.50 | 1.50 | 80 | 0.87 |
| 1¼ | 1.66 | 1.278 | 0.191 | 1.88 | 1.88 | 80 | 1.60 |
| 1½ | 1.90 | 1.500 | 0.200 | 2.25 | 2.25 | 80 | 2.30 |
| 2 | 2.38 | 1.944 | 0.218 | 2.50 | 2.50 | 80 | 3.90 |
| 2½ | 2.88 | 2.328 | 0.276 | 3.00 | 3.00 | 80 | 6.50 |
| 3 | 3.50 | 2.900 | 0.300 | 3.38 | 3.38 | 80 | 9.00 |
| 3½ | 4.00 | 3.364 | 0.318 | 3.75 | 3.75 | 80 | 12.20 |
| 4 | 4.50 | 3.826 | 0.337 | 4.12 | 4.12 | 80 | 16.20 |
| 5 | 5.56 | 4.810 | 0.375 | 4.88 | 4.88 | 80 | 26.60 |
| 6 | 6.62 | 5.756 | 0.432 | 5.62 | 5.62 | 80 | 41.80 |
| 8 | 8.62 | 7.620 | 0.500 | 7.00 | 7.00 | 80 | 76.20 |
| 10 | 10.75 | 9.562 | 0.594 | 8.50 | 8.50 | 80 | 120.00 |
| 12 | 12.75 | 11.374 | 0.688 | 10.00 | 10.00 | 80 | 175.00 |
| 14 | 14.00 | 12.500 | 0.750 | 11.00 | 11.00 | 80 | 240.00 |
| 16 | 16.00 | 14.312 | 0.844 | 12.00 | 12.00 | 80 | 290.00 |
| 18 | 18.00 | 16.124 | 0.938 | 13.50 | 13.50 | 80 | 360.00 |
| 20 | 20.00 | 17.938 | 1.031 | 15.00 | 15.00 | 80 | 450.00 |
| 24 | 24.00 | 21.562 | 1.219 | 17.00 | 17.00 | 80 | 630.00 |
Schedule 160
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center R | Center to End B | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.464 | 0.188 | 1.00 | 1.00 | 160 | 0.46 |
| ¾ | 1.05 | 0.612 | 0.219 | 1.12 | 1.12 | 160 | 0.73 |
| 1 | 1.32 | 0.820 | 0.250 | 1.50 | 1.50 | 160 | 1.09 |
| 1¼ | 1.66 | 1.160 | 0.250 | 1.88 | 1.88 | 160 | 2.00 |
| 1½ | 1.90 | 1.338 | 0.281 | 2.25 | 2.25 | 160 | 2.88 |
| 2 | 2.38 | 1.692 | 0.344 | 2.50 | 2.50 | 160 | 4.88 |
| 2½ | 2.88 | 2.130 | 0.375 | 3.00 | 3.00 | 160 | 8.13 |
| 3 | 3.50 | 2.624 | 0.438 | 3.38 | 3.38 | 160 | 11.25 |
| 4 | 4.50 | 3.438 | 0.531 | 4.12 | 4.12 | 160 | 20.25 |
| 5 | 5.56 | 4.310 | 0.625 | 4.88 | 4.88 | 160 | 33.25 |
| 6 | 6.62 | 5.182 | 0.719 | 5.62 | 5.62 | 160 | 52.25 |
| 8 | 8.62 | 6.808 | 0.906 | 7.00 | 7.00 | 160 | 95.25 |
| 10 | 10.75 | 8.500 | 1.125 | 8.50 | 8.50 | 160 | 143.75 |
| 12 | 12.75 | 10.126 | 1.312 | 10.00 | 10.00 | 160 | 211.25 |
| 14 | 14.00 | 11.188 | 1.406 | 11.00 | 11.00 | 160 | 296.25 |
| 16 | 16.00 | 12.812 | 1.594 | 12.00 | 12.00 | 160 | 355.00 |
| 18 | 18.00 | 14.438 | 1.781 | 13.50 | 13.50 | 160 | 441.25 |
| 20 | 20.00 | 16.062 | 1.969 | 15.00 | 15.00 | 160 | 552.50 |
| 24 | 24.00 | 19.312 | 2.344 | 17.00 | 17.00 | 160 | 781.25 |
Schedule XXS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center R | Center to End B | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.252 | 0.294 | 1.00 | 1.00 | * | 0.51 |
| ¾ | 1.05 | 0.434 | 0.308 | 1.12 | 1.12 | * | 0.80 |
| 1 | 1.32 | 0.604 | 0.358 | 1.50 | 1.50 | * | 1.20 |
| 1¼ | 1.66 | 0.896 | 0.382 | 1.88 | 1.88 | * | 2.20 |
| 1½ | 1.90 | 1.100 | 0.400 | 2.25 | 2.25 | * | 3.16 |
| 2 | 2.38 | 1.508 | 0.436 | 2.50 | 2.50 | * | 5.36 |
| 2½ | 2.88 | 1.776 | 0.552 | 3.00 | 3.00 | * | 8.94 |
| 3 | 3.50 | 2.300 | 0.600 | 3.38 | 3.38 | * | 12.38 |
| 4 | 4.50 | 3.152 | 0.674 | 4.12 | 4.12 | * | 22.28 |
| 5 | 5.56 | 4.060 | 0.750 | 4.88 | 4.88 | * | 36.58 |
| 6 | 6.62 | 4.892 | 0.864 | 5.62 | 5.62 | * | 57.48 |
| 8 | 8.62 | 6.870 | 0.875 | 7.00 | 7.00 | * | 104.78 |
| 10 | 10.75 | 8.750 | 1.000 | 8.50 | 8.50 | 140 | 158.13 |
| 12 | 12.75 | 10.750 | 1.000 | 10.00 | 10.00 | 120 | 232.38 |
Materials We Supply
Straight Tee 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 the difference between a straight tee and a reducing tee?
Branch size. On a straight tee all three ends are the same nominal size. On a reducing tee the branch is smaller than the run, which is the more common case when you are tapping a small line off a large header.
What do the C and M dimensions mean on a tee?
C is center-to-end along the run, and M is center-to-end on the branch. Both are measured from the intersection of the centerlines to the welding face, and both are listed in the table above by size and schedule.
Is a tee better than a weldolet for a full-size branch?
For a full-size branch, generally yes. A tee is a factory fitting made to ASME B16.9 with an established pressure rating, whereas a fabricated branch connection needs a reinforcement calculation. Branch fittings make more sense when the branch is much smaller than the header.
