With all nationally and internationally approved standards and specifications met, in terms of grade, quality, weight,
packing and other aspects, we manufacture and supply the plain round steel bars, deformed steel bars and binding
wires as follows;
• British Standards - BS 4449:1997 Grade 460B & BS 4449:2005 Grade B 500B
• American Standards - ASTM A 615 Grade 40/Grade 60
• National Iran Standard – ISIRI
Regrettably, mild steel bars produced in some African countries and other Non-African countries exhibit abysmally
low strength characteristics of Yield Strength (MPa) as follows;
As the main building materials in many construction work, our round and deformed bar range will assist any
construction and engineering project with the product quality assurance of Round/Deformed bar also commonly
known as Steel Reinforcing bars are produced by pouring molten steel into casters and then running it through a
series of standards in the mill, which shape the steel into reinforcing bars. The cross hatchings, called “deformations,”
help transfer the load between concrete and steel.
A deformed steel bar is an item that widely is used in construction in many countries in the world over. A deformed
steel bar is a reinforcing bar that normally is made from carbon steel. Typically, a deformed steel bar is utilized in
order to reinforce concrete. It is also utilized in the general reinforcement of masonry structures.
The standard deformed steel bar normally is designed with ridges that allow it to be more firmly anchored within concrete or masonry. In the construction industry, the standard deformed steel bar is also referred as reinforcing
In short, the deformed steel bar is an economical way of strengthening and improving the safety and durability of
concrete and masonry structures.
PURPOSES AND TYPES OF REINFORCING STEEL
Reinforced concrete was designed on the principle
that steel and concrete act together in resisting force.
Concrete is strong in compression but weak in tension.
The tensile strength is generally rated about 10 percent
of the compression strength. For this reason, concrete
works well for columns and posts that are compression
members in a structure. But, when it is used for tension
members, such as beams, girders, foundation walls,
or floors, concrete must be reinforced to attain the
necessary tension strength. Steel is the best material for reinforcing concrete because the properties of expansion for both steel and concrete
are considered to be approximately the same; that is, under normal conditions, they will expand and contract at an
almost equal rate.
NOTE: At very high temperatures, steel expands more rapidly than concrete and the two materials will separate.
Another reason steel works well as reinforcement for concrete
is because it bonds well with concrete. This bond strength is
proportional to the contact surface of the steel to the concrete.
In other words, the greater the surface of steel exposed to the
adherence of concrete, the stronger the bond. A deformed
reinforcing bar adheres better than a plain, round, or square
one because it has a greater bearing surface. In fact, when
plain bars of the same diameter are used instead of deformed
bars, approximately 40 percent more bars must be used.
The rougher the surface of the steel, the better it adheres to concrete. Thus steel with a light, firm layer of rust is
superior to clean steel; however, steel with loose or scaly rust is inferior. Loose or scaly rust can be removed from the
steel by rubbing the steel with burlap or similar material. This action leaves only the firm layer of rust on the steel to
adhere to the concrete.
NOTE: Reinforcing steel must be strong in tension and, at the same time, be ductile enough to be shaped or bent
Reinforcing steel can be used in the form of bars or rods that are either plain or deformed or in the form of expanded
metal, wire, wire fabric, or sheet metal. Each type is useful for different purposes, and engineers design structures
with those purposes in mind.
Plain bars are round in cross section. They are used in concrete
for special purposes, such as dowels at expansion joints, where
bars must slide in a metal or paper sleeve, for contraction joints in
roads and runways, and for column spirals. They are the least used
of the rod type of reinforcement because they offer only smooth,
even surfaces for bonding with concrete.
Deformed bars differ from the plain bars in that they have either
indentation in them or ridges on them, or both, in a regular pattern. The twisted bar, for example, is made by
twisting a plain, square bar cold. The spiral ridges, along the surface of the deformed bar, increase its bond strength
with concrete. Other forms used are the round and square corrugated bars. These bars are formed with projections
around the surface that extend into the surrounding concrete and prevent slippage. Another type is formed with
longitudinal fins projecting from the surface to prevent twisting. In the United States, deformed bars are used almost
exclusively; while in Europe, both deformed and plain bars are used.
Eleven standard sizes of
reinforcing bars are in use
today. Remember that bar
numbers are based on the
nearest number of one-eighth
inch included in the nominal
diameter of the bar. To measure
rebar, we must measure across
the round/square portion
where there is no deformation.
The raised portion of the
deformation is not measured
when measuring the rebar
Reinforcing bars are hot-rolled from a variety of steels in several different strength grades. Most reinforcing bars are
rolled from new steel billets, but some are rolled from used railroad-car axles or railroad rails that have been cut into
rollable shapes. Assortments of strengths are available.
The American Society for Testing Materials (ASTM) has
established a standard branding for deformed reinforcing bars.
There are two general systems of bar branding. Both systems
serve the basic purpose of identifying the marker size, type of
steel, and grade of each bar. In both systems an identity mark
denoting the type of steel used is branded on every bar by
engraving the final roll used to produce the bars so as to leave
raised symbols between the deformations. The manufacturer’s
identity mark that signifies the mill that rolled the bar is usually
a single letter or, in some cases, a symbol. The bar size follows the manufacturer’s mark and is followed by a symbol
indicating new billet steel (-N-), rolled rail steel (-I-), or rolled axle steel (-A-). Figure 7-2 shows the two-grade
The lower strength reinforcing bars show
only three marks: an initial representing
the producing mill, bar size, and type of
steel. The high strength reinforcing bars
use either the continuous line system or
the number system to show grade marks.
In the line system, one continuous line is
rolled into the 60,000 psi bars, and two
continuous lines are rolled into the 75,000
psi bars. The lines must run at least five
deformation spaces, In the number system,
a “60” is rolled into the bar following the
steel type of mark to denote 60,000 psi
bars, and a “75” is rolled into the 75,000
Expanded Metal and Wire Mesh Reinforcement
Expanded metal or wire mesh is also used for reinforcing
concrete. Expanded metal is made by partly shearing a
sheet of steel, as shown in view A. The sheet steel has
been sheared in parallel lines and then pulled out or
expanded to form a diamond shape between each parallel
cut. Another type is square, rather than diamond shaped,
as shown in view B. Expanded metal is customarily used
during plastering operations and light reinforcing concrete
construction, such as sidewalks and small concrete pads
that do not have to bear substantial weight, such as
transformer and air-conditioner pads.
Welded Wire Fabric
Welded wire fabric is fabricated from a series of wires
arranged at right angles to each other and electrically
welded at all intersections. Welded wire fabric, referred to as
WWF within the NCF. has various uses in reinforced concrete
construction. In building construction, it is most often used
for floor slabs on well-compacted ground. Heavier fabric,
supplied mainly in flat sheets, is often used in walls and for
the primary reinforcement in structural floor slabs. Additional
examples of its use include road and runway pavements, box
culverts, and small canal linings.
Four numbers are use-d to designate the style of wire mesh; for example, 6 by 6-8 by 8 (sometimes written
6x6x8x8or6x6-W2.1xW2.1).The first number (in this case, 6) indicates the lengthwise spacing of the wire in inches;
the second number (in this case, 6) indicates the crosswise spacing of the wire in inches; the last two numbers (8
by 8) indicate the size of the wire on the Washburn and Moen gauge. More recently the last two numbers are a W
number that indicates the size of the cross-sectional area in the wire in hundredths of an inch. WWF is currently
available within the Navy stock system using the four-digit system, 6 by 6-8 by 8, as of this writing, but if procured
through civilian sources, the W system is used.
Light fabric can be supplied in either rolls
or flat sheets. Fabric made of wire heavier
than W4 should always be furnished in flat
sheets. Where WWF must be uniformly flat
when placed, fabric furnished in rolls should
not be fabricated of wire heavier than W 2.9.
Fabricators furnish rolled fabric in complete
rolls only. Stock rolls will contain between 700
to 1,500 square feet of fabric determined by
the fabric and the producing location. The
unit weight of WWF is designated in pounds
per one hundred square feet of. Five feet, six
feet, seven feet, and seven feet six inches are
the standard widths available for rolls, while
the standard panel widths and lengths are
seven feet by twenty feet and seven feet six
inches by twenty feet.
Sheet-metal reinforcement is used mainly in floor slabs and in stair and roof construction. It consists of annealed
sheet steel bent into grooves or corrugations about one-sixteenth inch (1.59 mm) in depth with holes punched at
Tension in Steel
Steel bars are strong in tension. Structural grade is capable of safely carrying up to 18,000 psi and intermediate, hard,
and rail steel, 20,000 psi. This is the SAFE or WORKING STRESS; the BREAKING STRESS is about triple this.
When a mild steel bar is pulled in a testing machine, it stretches a very small amount with each increment of load. In
the lighter loadings, this stretch is directly proportional to the amount of load. The amount is too small to be visible
and can be measured only with sensitive gauges.
At some pull (known as the YIELD POINT), such as 33,000 psi for mild steel, the bar begins to neck down (view B) and
continues to stretch perceptibly with no additional load.
Then, when it seems the bar will
snap like a rubber band it recovers
strength (due to work hardening).
Additional pull is required (view C)
to produce additional stretch and
final failure (known as the ULTIMATE
STRENGTH) at about 55,000 psi for