Mild Steel Angle Size Chart: Dimensions, Weight Formula & Standard Sizes Explained
In this blog, we’ll break down the properties, applications, and advantages of oxygen-free copper, helping you understand why it’s preferred over standard copper in various industries.
Introduction
Mild Steel (MS) angles, also called angle iron or L-angles, are among the most versatile structural steel sections used across construction, fabrication, and manufacturing. But choosing the correct size — and accurately calculating its weight — requires understanding how the standard MS Angle size chart is structured.
This guide walks through MS angle types, standard dimensions, the weight calculation formula, and how to interpret a size chart so you can order the right material the first time.
What Is an MS Angle?
An MS angle is an L-shaped structural steel section with two legs set at 90 degrees to each other. Angles are manufactured in two main configurations:
- Equal Angles — both legs are the same length (e.g., 50mm x 50mm)
- Unequal Angles — legs are of different lengths (e.g., 75mm x 50mm)
MS angles are produced according to IS 808:1989, the same standard governing channels and beams, and are typically designated by their leg lengths and thickness, e.g., ISA 50x50x6.
Common Applications of MS Angles
- Structural framing and support brackets
- Tower and transmission line structures
- Racking, shelving, and storage systems
- Machine bases and equipment frames
- Cross-bracing in trusses and platforms
- Gate and grill fabrication
How to Read an MS Angle Size Chart
A standard MS angle chart lists the following details for each size:
| Parameter | Description |
|---|---|
| Designation | e.g., ISA 40x40x5, ISA 65x65x6 |
| Leg Length (A x B) | Length of each leg in mm |
| Thickness (t) | Thickness of the angle section in mm |
| Sectional Area | Cross-sectional area (cm²) |
| Weight per Meter | Mass per running meter (kg/m) |
| Centre of Gravity (Cx, Cy) | Used in structural calculations |
Sample MS Angle Weight Chart (Equal Angles)
| Designation | Size (mm) | Thickness (mm) | Approx. Weight (kg/m) |
|---|---|---|---|
| ISA 25×25 | 25×25 | 3 | ~1.1 |
| ISA 40×40 | 40×40 | 5 | ~2.9 |
| ISA 50×50 | 50×50 | 6 | ~4.5 |
| ISA 65×65 | 65×65 | 6 | ~5.9 |
| ISA 75×75 | 75×75 | 8 | ~9.0 |
| ISA 90×90 | 90×90 | 8 | ~10.9 |
| ISA 100×100 | 100×100 | 10 | ~15.0 |
| ISA 130×130 | 130×130 | 10 | ~19.8 |
Note: These are indicative reference values based on standard IS 808 tables. Always verify final figures with your supplier’s current mill certificate, as thickness variants (e.g., ISA 50x50x5 vs 50x50x6) change the weight significantly.
MS Angle Weight Formula
The theoretical weight of an MS angle is calculated using this standard formula:
Weight (kg/m) = 0.00785 × t × (A + B − t)
Where:
- t = thickness of the angle (mm)
- A = length of leg 1 (mm)
- B = length of leg 2 (mm)
- 0.00785 = density factor for mild steel (derived from 7.85 g/cm³)
For equal angles, A and B are the same value. This formula gives a close theoretical approximation; actual rolled weight may vary marginally due to manufacturing tolerances.
Worked Example
For an ISA 50x50x6 angle:
Weight = 0.00785 × 6 × (50 + 50 − 6) Weight = 0.00785 × 6 × 94 Weight ≈ 4.43 kg/m
Equal vs Unequal Angles: Which One to Choose?
- Equal angles are typically used where symmetrical load distribution is needed — bracing, frames, and general fabrication.
- Unequal angles are chosen when one direction needs more strength or stiffness than the other, such as in certain truss or support applications where load paths are asymmetric.
Tips for Accurate Angle Selection
- Match thickness to load requirements — don’t just pick by leg length; thickness has a major effect on strength and weight.
- Account for corrosion allowance — for outdoor or humid environments, factor in a slightly higher thickness or opt for galvanised angles.
- Cross-check with IS 808 — especially for structural design submissions, since approximate online charts can vary slightly between sources.
- Confirm weight tolerance — IS standards typically allow a small percentage variation from theoretical weight; ask your supplier for their tested tolerance range.
Frequently Asked Questions
1. What is the difference between equal and unequal MS angles? Equal angles have both legs of the same length (e.g., 50x50mm), giving symmetrical strength in both directions. Unequal angles have legs of different lengths (e.g., 75x50mm), which is useful when one direction of a structure needs more stiffness than the other.
2. How do I calculate the weight of an MS angle without a chart? Use the formula: Weight (kg/m) = 0.00785 × t × (A + B − t), where t is thickness and A, B are the leg lengths in mm. This gives a close theoretical estimate of the weight per meter.
3. Does angle thickness affect weight more than leg length? Both matter, but thickness has a disproportionate effect since it’s multiplied directly in the formula. Two angles with the same leg length but different thickness can have noticeably different weights per meter.
4. Can MS angles be used for load-bearing structures? Yes, MS angles are commonly used in bracing, brackets, and lighter structural framing. However, for primary load-bearing members in larger structures, beams (ISMB) or channels (ISMC) are typically preferred due to higher bending resistance.
Conclusion
Understanding the MS angle size chart — and knowing how to independently verify weight using the standard formula — puts you in a much stronger position when planning procurement, costing, or structural design. Whether you’re building a rack system or reinforcing a structural frame, getting the right angle size and thickness combination is key to both safety and cost efficiency.
Browse our [MS Angle Weight Chart] for the complete range of equal and unequal angle sizes, or head to our [Angle Products] page for live stock and pricing.
FAQ's
Need Help?
We're Here for You!
Feel free to contact us any time. we will get back to you as soon as we can!
Ask Anything
Do you have any questions?
A: Carbon steel relies on carbon content alone for its properties. Alloy steel adds elements like chromium, nickel, molybdenum, and vanadium to achieve specific improvements — higher strength, better low-temperature toughness, creep resistance, or corrosion resistance — giving it a far broader performance range than carbon steel.
A: For ambient to 400°C service, ASTM A516 Grade 70 is the standard choice. For high-temperature refinery or power plant use (up to 600°C), ASTM A387 Grade 11 or 22 (chrome-moly) applies. For cryogenic service down to -196°C, 9% nickel steel (ASTM A553) is required.
A: Wear-resistant grades like AR400/AR500 are quenched to martensitic hardness of 370–500 HB — 3–4× harder than structural grades like A572-50. They resist abrasive wear in mining and construction equipment but have limited weldability and are not suitable as primary structural members.
A: CE (= C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15) predicts susceptibility to hydrogen-induced cold cracking during welding. Sheets with CE above ~0.40 require preheating to slow cooling and allow hydrogen diffusion, preventing weld cracking. Always develop a qualified WPS based on the specific CE value.
