It is often asked that I-beam and H-beam are similar in shape, how to choose in practical application?
Many people who have worked in the construction industry for many years cannot explain in detail.
Here’s a detailed explanation.
It can be seen from the shape that H-shaped steel and I-shaped steel are different, as shown in the following figure:
H-beam vs I-beam Steel
Through the above explanation of H-beam and I-beam, we have clearly understood the definition of H-beam and I-beam.
What is the difference between H-beam and I-beam?
Related reading: online H-beam & I-beam Weight Calculator
Difference #1
The moment of inertia of the section is quite different because the cross section size of I-beam is relatively high and narrow, no matter it’s ordinary I -beam or light-duty I beam.
Therefore, they generally can only be applied directly to the parts with bending in its web plane or to form lattice-type force-bearing parts.
It is not suitable for the axially-compressed structural parts or the bending parts perpendicular to the plane of the web, which makes it very limited in application.
Difference #2
H-beam steel belongs to high-efficiency economic cutting profile (others include cold-bent thin-walled section steel, profiled steel plates, etc.)
Due to the reasonable cross-section shape, they can make the steel function better and bear a higher load.
Different from the common I-beam, the flanges of H-beam steel are widened, and the inner and outer surfaces are usually parallel, which makes them strong in connecting high-strength bolts and other components.
With reasonable sizes and complete models, they are convenient for design and selection (except the I-beam steel for crane beams).
Difference #3
The flanges of H-beam steel are all of the equal thickness, with rolling sections.
H-beams also have a combined section consisting of 3 plates welded together.
I-beams are rolled section.
The inner edges of the inside flanges have a 1:10 slope because of the poor production technique.
The rolling of H-beam steel is different from that of ordinary I-beam which uses only one set of horizontal rolls.
Due to its wide flange and no slope (or very small slope), a set of the vertical roll must be added for simultaneous rolling.
As a result, the rolling process and equipment are more complicated than the ordinary rolling mill.
The max height of rolled H-beam that can be produced in China is 800mm, and if the higher height is required, it has to be welded.
Difference #4
In China, the national standard of hot-rolled H-beam steel (GB/ t11263-1998) divides H-beam steel into three categories whose codes are hz, hk and hu respectively:
- narrow flange
- wide flange
- steel pile
The narrow flange H-beam is suitable for the beams or bending parts, while the wide flange H-beam steel and H-beam steel pile are suitable for axial compression structural parts or bending parts.
Comparing I-beam with H-beam steel under the same weight, w, ix and iy of I-beam are not as good as H-beam steel.
Difference #5
I-beam is small in length, high in height and can only bear the force in one direction.
Difference #6
H-beam steel has a deep groove, large thickness and can withstand forces in two directions.
Difference #7
As the demand for steel structure building grows, I-beam alone can not meet the demand because even thicken I-beams are unstable when used in load-bearing columns.
Difference #8
I-beam can only be used for beams while H-beam steel can be used for load-bearing columns.
Difference #9
H-beam steel is economical section steel with better mechanical properties in section than I-beam.
It is so named because the shape of its cross-section is the same as the English letter “H”.
The flanges of hot-rolled H-beam steel are wider than that of I-beams, have greater lateral stiffness, and are more resistant to bending.
H-beams are lighter than I-beams under the same specifications.
Difference #10
The flange of I-beam is thick near the web while thin in the outsider.
The flange of H-beam steel is equal in cross-sections.
Difference #11
HW, HM, HN, H are the general names for H-beam steel.
H-beam steel is welded while HW, HM, HN are hot rolled.
Difference #12
HW refers to H-beam steel which basically has the same height and flange width, mainly used for steel core column in reinforced concrete frame column, also known as stiff steel column.
It’s mainly used for the column in the steel structure.
Difference #13
HM refers to H-beam steel with the ratio of the height to the width of flange is roughly 1.33~~1.75;
HM is mainly used in steel structure: as steel frame column or frame beam in the frame structure bearing dynamic load, for example: equipment platforms.
Difference #14
HN refers to H-beam steel whose height to flange width ratio is greater than or equal to 2;
HN is mainly used in beams, which is similar to the usage of I-beam steel.
How can I-beam and H-beam be distinguished?
- Distinguish by appearance:
As shown in the name, I-shaped steel is a “I” shaped section steel.
The inner surface of the upper and lower flanges has an inclination, generally 1:6, so that the flange is thin outside and thick inside;
H-section steel is a kind of economic section high-efficiency profile with more optimized section area distribution and more reasonable strength weight ratio.
It is named after its section is the same as the English letter “H”.
- Distinguish by flange:
The I-beam flange is thick near the web of the wearing surface and thin outside;
The flange of H-section steel is equal wearing surface.
- Distinguish by steel trough:
The side length of I-beam is small and the height is large, so it can only bear the force in one direction;
H-shaped steel groove is deep and thick, and can withstand forces in two directions.
How are I-beam and H-beam classified?
Classification of I-beam:
I-beam is mainly divided into ordinary I-beam, light I-beam and wide flange I-beam.
According to the height ratio of flange to web, it can be divided into wide, medium, narrow and wide flange I-beam.
The specification of the wide and medium wide flange I-beam is #10-60, that is, the corresponding height is 10 cm-60 cm.
At the same height, the light I-beam flange is narrow, the web is thin, and the weight is light.
Wide flange I-beam, also known as H-beam, is characterized by two parallel legs and no inclination inside the legs.
It belongs to economic section steel and is rolled on four high universal mill, so it is also called “universal I-beam”.
Ordinary I-beam and light I-beam have formed national standards.
Classification of H-section steel:
(1) According to the flange width of the product, it is divided into wide flange, middle flange and narrow flange H-beam.
The flange width B of wide flange and middle flange H-beam steel is greater than or equal to the web height H.
The flange width B of the narrow flange H-beam steel is about half of the web height H.
(2) It is divided into H-shaped steel beam, H-shaped steel column, H-shaped steel pile and H-shaped steel beam with extremely thick flange according to product use.
What Is I-beam Steel?
I-beam steel, as shown in the name, is a type of steel with cross-section looks like the character “I”.
The inner surface of the upper and lower flanges of the I-beam has a slope, generally 1: 6, which makes the flanges thin outside and thick inside.
As a result, the cross-section characteristics of I-beams in the two main planes are greatly different, and it is difficult to exert the strength in practical applications.
Although there is thicker I-beam in the I-beam steel market, the structure of I-beam has already determined its shortage in torsion resistance.
What is H-beam Steel?
H-section steel is widely used section steel in today’s steel structure buildings. It has many differences compared to I-beams.
The first is the flange difference and the second is that it has no inclination inside the flange and the upper and lower surfaces are parallel.
The cross-section characteristic of H-beam steel is significantly better than that of traditional I-beam, channel steel and angle steel.
H-beam steel, which is named after the alphabet “H” because its cross-section shape is similar to this letter, is an economical section steel with more optimized section area distribution, more reasonable strength-to-weight ratio.
It’s also been called W-beam, which means wide flange beam.
There is no slant between the two outside beams of H-beam steel, namely, they are straight.
This makes the welding of H-beam steel simpler than that of I-beam.
H-beam steel has better mechanical properties per unit weight, which can save a lot of material and construction time.
The cross-section of I-beam steel has better direct pressure bearing and tensile-resistant. However, the section size is too narrow to resist twisting. H-beam steel is the opposite.
They both have advantages and disadvantages.
Which of H-beam steel and I-beam steel bears better load?
H steel is better for load-bearing.
Whether I-shaped steel is ordinary or light, due to the relatively high and narrow cross-sectional dimensions, the inertia moments of the two main axes on the cross-section differ greatly.
Therefore, it can only be directly used for the members subjected to bending in the plane of their webs, or it can be formed into lattice stress-bearing members.
It is not suitable for axial compression members or members with bending perpendicular to the plane of the web, which makes it very limited in the scope of application.
H-section steel is a kind of high-efficiency and economical profile. Due to the reasonable section shape, they can make the steel more effective and improve the cutting capacity.
Different from the ordinary I-shape, the flange of H-shaped steel is widened, and the inner and outer surfaces are usually parallel, so it is convenient to connect with other members with high-strength bolts.
Its size constitutes a reasonable series, and its models are complete, which is convenient for design and selection.
You can click below link to download steel beam load bearing calculator.
It’s Free.
Features of H beam steel
The inner and outer sides of the flange of H-shaped steel are parallel or nearly parallel, and the end of the flange is at right angles, so it is named parallel flange I-beam.
The web thickness of H-shaped steel is smaller than that of ordinary I-beam with the same height as the web, and the flange width is larger than that of ordinary I-beam with the same height as the web, so it is also called wide edge I-beam.
Determined by the shape, the section modulus, inertia moment and corresponding strength of H-beam are obviously better than those of ordinary I-beam with the same single weight.
When used in metal structures with different requirements, it shows its superior performance in terms of bending moment, pressure load and eccentric load.
It can greatly improve the bearing capacity and save 10% ~ 40% of metal compared with ordinary I-beam.
How to calculate load bearing of I-beam?
The bending bearing capacity formula is:
Mu=b’*h’*f*(0.5*h-0.5*h’)+(0.5*h-h’)*b*f*0.5*(0.5*h-h’)
F – design value of yield strength
b – web thickness
b ‘- flange width
h – high
h ‘- flange thickness
As for the bearing capacity of tension and compression, I think it is not necessary for me to explain here. As for eccentric tension and compression, it is not very difficult to calculate by yourself.
For example:
How much can I-beam #25 bear when the span is 4m and the load is evenly distributed?
Calculation:
For #25 I-beam, W = 401.4cm3, [σ]=210N/mm2, overall stability coefficient φb=0.93
Bending moment formula M = QL2/8
Strength formula σ = M/W
According to the formula:
q=8σW/L2=8*210*401400/4*4=42.1kN/m
Overall stability requirement: 42.1 * 0.93 = 39.2kn/m
Partial factor requirement (safety factor): 39.2 / 1.4 = 28kN/m
Safe use: 28kN/m
The above calculation does not consider the self weight and deflection checking calculation of I-beam.
What are the applications of I-beam and H-beam?
Purpose of I-beam:
Ordinary I-beam and light I-beam have relatively high and narrow cross-sectional dimensions, so the inertia moment of the two main sleeves on the cross-section differs greatly, which makes it very limited in the application range.
I-beam is not suitable for axial compression members or members that are bent perpendicular to the web plane, which makes its application scope very limited.
I-beam is widely used in buildings and other metal structures.
Purpose of H-beam:
Mainly used for various civil and industrial building structures;
Various large-span industrial plants and modern high-rise buildings, especially those in areas with frequent seismic activities and under high-temperature working conditions;
Large bridges with large bearing capacity, good section stability and large span, heavy equipment, highways, ship skeleton, mine support, foundation treatment and embankment engineering, and various machine components are required.
- Various civil and industrial building structures;
- Various large-span industrial plants and modern high-rise buildings, especially those in areas with frequent seismic activities and under high-temperature working conditions;
- Heavy equipment;
- Expressway;
- Ship skeleton;
- Various machine components.
What are the characteristics of I-beam and H-beam?
Characteristics of I-beam:
I-beam has the characteristics of narrow flange, thin web and light weight.
Characteristics of H-beam:
The inner and outer sides of the flange of H-shaped steel are parallel or nearly parallel, and the end of the flange is at right angles, so it is named parallel flange I-beam.
The web thickness of H-shaped steel is smaller than that of ordinary I-beam with the same height as the web, and the flange width is larger than that of ordinary I-beam with the same height as the web, so it is also called wide flange I-beam.
Determined by the shape, the section modulus, inertia moment and corresponding strength of H-beam are obviously better than those of ordinary I-beam with the same single weight.
Very informative and technical comparison between the two steel sections which are most commonly used in the industry.
Glad to hear that and thanks for your comments.
As a historian who regularly deals with technology and industrial-related artifacts, I found this piece to be quite informative. Thank you. But a quick question…. I understand the structural differences between an H-beam vs an I-beam (i.e., tapered flanges on the I-beam), but is there an expectation regarding the width of the flange on an H-beam? Which, more specifically, is to ask if the flange needs to be as wide as the web is deep? Or can the flange width be less than the depth of the web? Thanks very much!
Well, the different types of H beam got different standard, for W-section, web:flange almost 1:1, for M-section, web:flange=1.33 – 1.75, for N-section, web:flange≥2. So, yes, flange can be less than the depth of the web.
im afraid the expanation ist not quite correct.
I-beam ist the definition of the din (germany) for many decades and replaced the older term doppel-t. its used for the closed calibre products and the open calibres as well. (paralell and sloped). the newer term “h” ist a european definition for the closed calibres, for the open calibres (sloped) remains the i-term (less important in use).
there is no connection between the shape of the letter and the shape of the form (sloped, paralell flanges).
for me the i-termination is the logical one for all series because theese beams are nearly for 99,9 % used as a “i” (upright), extremely seldom as a “h” horizontally because of the “widerstandsmoment” (don´t know the correct translation) ;-)
hello from cologne, thomas müller, dipl.-ing.
Thanks Thomas, hope your explanation can help more readers of this article.
Dear Sir
Im looking for H beam steel material alloy steel or recomended steel for manufacuring plat foarm for truck
heavy eweight
Our sales team will contact you.
#1. H beams are welded.
#2. I beams are not welded
#3. H beams are heavier
#4. I beams are lighter
#5. When the heavy H beams are used horizontally to support cantilevered concrete, unnecessary weight is being placed on the structures foundation which could create loading bearing issues in the foundation. While H beams are good for load bearing columns, they wreak havoc when used horizontally due to their sheer wieght alone.
Brian, many thanks for your kindly answer.
Building a small “over a creek” bridge. Width 12 feet. Crossing length 10 1/2 feet.
Need 2 I-beams 12 feet long by 2 to 3″ high, AND 5 crossing beams 10 1/2″ long by 4″ or 6″ high…topping will be 3″ x12″ wide x 12″ long center cut oak planks.
Your suggestions, and quote, please. Bob Heltman [email protected]
HI
WE WANT TO BUILD 16 MTR X 60MTR X 7 MTR HEIGHT SHEAD WITH H BEAM AND TRI -ANGLE
WHICH KIND OF H-BEAM AND ANGLE SUGGEST BY YOU.?
AND TOTAL HOW MANY KG STEEL NEEDED?
I am wanting to replace a header for a garage door (18’ door). Presently the header is 2” x 12” lumber sandwiched together.
It is 11.5” tall I need something 4” to 5” tall that will support the load.
I am thinking H or I beams
What are your thoughts??
We have to barns 45′ apart, we want to connect them with a roof only using a H-Beam 45′ long, what size H-Beam would we need ? It will carry trusses, lath & metal roofing.