90 Degree Butt Weld Elbow Weight Formula
For carbon steel butt weld elbows, the weight is most commonly calculated on the basis of the 90 degree long radius (1.5D) elbow, because it is the most widely used type. The formula is:
W = 0.0387 × S × (D − S) × R / 1000 (kg per piece)
Where:
- W — weight in kilograms per piece
- S — wall thickness in millimetres
- D — outside diameter in millimetres
- R — bending radius, where LR (long radius) = 1.5 × D and SR (short radius) = 1 × D
For a 45 degree elbow, the weight is approximately 0.6 times the weight of a 90 degree elbow of the same size and schedule.
Carbon Steel 90° LR Elbow Weight Chart (kg/piece)
The table below lists reference weights for ASTM A234 WPB carbon steel 90 degree long radius butt weld elbows across common nominal sizes and schedule walls.
| DN | NPS | Sch 10 | STD / Sch 40 | XS / Sch 80 |
|---|---|---|---|---|
| 15 | 1/2" | 0.06 | 0.08 | 0.11 |
| 20 | 3/4" | 0.08 | 0.11 | 0.14 |
| 25 | 1" | 0.13 | 0.16 | 0.24 |
| 32 | 1-1/4" | 0.21 | 0.28 | 0.47 |
| 40 | 1-1/2" | 0.28 | 0.40 | 0.53 |
| 50 | 2" | 0.47 | 0.71 | 0.98 |
| 65 | 2-1/2" | 0.79 | 1.42 | 1.87 |
| 80 | 3" | 1.16 | 2.22 | 3.01 |
| 100 | 4" | 2.02 | 4.22 | 5.86 |
| 125 | 5" | 3.46 | 7.15 | 10.2 |
| 150 | 6" | 4.98 | 11.2 | 16.8 |
| 200 | 8" | 9.57 | 22.4 | 34.1 |
| 250 | 10" | 16.7 | 39.7 | 63.2 |
| 300 | 12" | 25.9 | 58.3 | 104 |
| 350 | 14" | 34.7 | 74.9 | 146 |
| 400 | 16" | 45.4 | 98.3 | 215 |
Values are reference figures in kg/piece and may vary slightly by manufacturer. Contact our team for the complete weight table up to DN1200 or for specific schedules.
Worked Example: 12" Sch 40 90° LR Elbow
Let us calculate the weight of a 90 degree long radius seamless elbow, 12" (DN300), Sch 40, ASTM A234 WPB.
- Outside diameter (D) = 323.9 mm
- Wall thickness (S) = 9.52 mm
- Radius (R) = 1.5 × 323.9 = 485.85 mm
W = 0.0387 × 9.52 × (323.9 − 9.52) × 485.85 / 1000 ≈ 56 kg/piece
This matches the reference table value for DN300 (58.3 kg), confirming the calculation method is accurate for estimating shipping weight and material cost.
Why Weight Matters for Your Order
Knowing the accurate fitting weight is essential for three practical reasons: it determines the freight cost for sea or air shipment, it lets you budget raw material accurately, and it helps you verify the wall thickness you specified. If you order in bulk, even a small difference per piece adds up to significant tonnage.
For carbon steel and stainless steel butt weld fittings, we supply elbows, tees, reducers, flanges and caps to ASME B16.9 elbow and related standards with full mill test certificates.
Frequently Asked Questions
How do I calculate the weight of a 45 degree elbow?
Multiply the weight of the equivalent 90 degree elbow by 0.6. For example, a 6" Sch 40 45° LR elbow weighs about 11.2 × 0.6 = 6.7 kg.
What is the difference between LR and SR elbow weight?
Short radius (1D) elbows use R = 1 × D instead of 1.5 × D, so they weigh roughly two-thirds of the equivalent long radius elbow.
Do you provide a complete weight chart up to DN1200?
Yes. Contact our team and we will send the full reference weight table for all sizes and schedules, including stainless steel grades 304/316.
Is the weight affected by material grade?
Yes. Stainless steel weighs slightly more than carbon steel (about 7.93 vs 7.85 g/cm³). For critical projects we recalculate using the exact material density.
Need custom sizes or a confirmed weight list for your project? Request a quote and our engineers will respond within 24 hours.