Lead was one of the first metals known to man. Probably the oldest
lead artifact is a figure made about 3000 BC. All civilizations,
beginning with the ancient Egyptians, Assyrians, and Babylonians, have
used lead for many ornamental and structural purposes. Many magnificent
buildings erected in the 15th and 16th centuries still stand under their
original lead roofs.
Compositions and Grades
Bellow is listed the Unified Numbering System (UNS) designations for
various pure lead grades and lead-base alloys.
- Pure leads L50000 - L50099
- Lead - silver alloys L50100 - L50199
- Lead - arsenic alloys L50300 - L50399
- Lead - barium alloys L50500 - L50599
- Lead - calcium alloys L50700 - L50899
- Lead - cadmium alloys L50900 - L50999
- Lead - copper alloys L51100 - L51199
- Lead - indium alloys L51500 - L51599
- Lead - lithium alloys L51700 - L51799
- Lead - antimony alloys L52500 - L53799
- Lead - tin alloys L54000 - L55099
- Lead - strontium alloys L55200 - L55299
Grades of lead
Grades are pure lead (also called corroding lead) and common lead
(both containing 99.94% min lead), and chemical lead and acid-copper lead
(both containing 99.90% min lead). Lead of higher specified purity
(99.99%) is also available in commercial quantities. Specifications other
than ASTM B 29 for grades of pig lead include federal specification
QQ-L-171, German standard DIN 1719, British specification BS 334,
Canadian Standard CSA-HP2, and Australian Standard 1812.
Corroding Lead. Most lead produced in the United States is pure
(or corroding) lead (99.94% min Pb). Corroding lead which exhibits the
outstanding corrosion resistance typical of lead and its alloys.
Corroding lead is used in making pigments, lead oxides, and a wide variety
of other lead chemicals.
Chemical Lead. Refined lead with a residual copper content of
0.04 to 0.08% and a residual silver content of 0.002 to 0.02% is
particularly desirable in the chemical industries and thus is called
Copper-bearing lead provides corrosion protection comparable to
that of chemical lead in most applications that require high corrosion
resistance. Common lead, which contains higher amounts of silver and
bismuth than does corroding lead, is used for battery oxide and general
Because lead is very soft and ductile, it is normally used
Commercially as lead alloys. Antimony, tin, arsenic, and calcium are the
most common alloying elements. Antimony generally is used to give
greater hardness and strength, as in storage battery grids, sheet, pipe,
and castings. Antimony contents of lead-antimony alloys can range from
0.5 to 25%, but they are usually 2 to 5%.
Lead-calcium alloys have replaced lead-antimony alloys in a
number of applications, in particular, storage battery grids and casting
applications. These alloys contain 0.03 to 0.15% Ca. More recently,
aluminum has been added to calcium-lead and calcium-tin-lead alloys as a
stabilizer for calcium. Adding tin to lead or lead alloys increases
hardness and strength, but lead-tin alloys are more commonly used for
their good melting, casting, and wetting properties, as in type metals
and solders. Tin gives the alloy the ability to wet and bond with metals
such as steel and copper; unalloyed lead has poor wetting characteristics.
Tin combined with lead and bismuth or cadmium forms the principal
ingredient of many low-melting alloys.
Arsenical lead (UNS L50310) is used for cable sheathing. Arsenic is often
used to harden lead-antimony alloys and is essential to the production of
round dropped shot.
Properties of Lead
The properties of lead that make it useful in a wide variety of
applications are density, malleability, lubricity, flexibility,
electrical conductivity, and coefficient of thermal expansion, all of
which are quite high; and elastic modulus, elastic limit, strength,
hardness, and melting point, all of which are quite low. Lead also has
good resistance to corrosion under a wide variety of conditions. Lead is
easily alloyed with many other metals and casts with little
The high density of lead (11.35 g/cm3, at room temperature) makes it very
effective in shielding against x-rays and gamma radiation. The
combination of high density, high limpness (low stiffness), and high
damping capacity makes lead an excellent material for deadening sound and
for isolating equipment and structures from mechanical vibrations.
Malleability, softness, and lubricity are three related properties that
account for the extensive use of lead in many applications.
The low tensile strength and low creep strength of lead must always be
considered when designing lead components. The principal limitation on
the use of lead as a structural material is not its low tensile strength
but its susceptibility to creep. Lead continuously deforms at low
stresses and this deformation ultimately results in failure at stresses
far below the ultimate tensile strength. The low strength of lead does
not necessarily preclude its use. Lead products can be designed to be
self-supporting, or inserts or supports of other materials can be
provided. Alloying with other metals, notably calcium or antimony, is a
common method of strengthening lead for many applications. In general,
consideration should always be given to supporting lead structures by
lead-covered steel straps. When lead is used as a lining in a structure
made of a stronger material, the lining can be supported by bonding it
to the structure. With the development of improved bonding and adhesive
techniques, composites of lead with other materials can be made.
Composites have improved strength yet also retain the desirable
properties of lead.
Products and Applications
The most significant applications of lead and lead alloys are
lead-acid storage batteries (in the grid plates, posts, and connector
straps), ammunition, cable sheathing, and building construction materials
(such as sheet, pipe, solder, and wool for caulking). Other important
applications include counterweights, battery clamps and other cast
products such as: bearings, ballast, gaskets, type metal, terneplate, and
foil. Lead in various forms and combinations is finding increased
application as a material for controlling sound and mechanical
vibrations. Also, in many forms it is important as shielding against
x-rays and, in the nuclear industry, gamma rays. In addition, lead is
used as an alloying element in steel and in copper alloys to improve
machinability and other characteristics, and it is used in fusible
(low-melting) alloys for fire sprinkler systems.
Battery Grids. The largest use of lead is in the manufacture of
lead-acid storage batteries. These batteries consist of a series of grid
plates made from either cast or wrought calcium lead or antimonial lead
that is pasted with a mixture of lead oxides and immersed in sulfuric
Type metals, a class of metals used in the printing industry,
generally consist of lead-antimony and tin alloys. Small amounts of
copper are added to increase hardness for some applications.
Cable Sheathing. Lead sheathing extruded around electrical
power and communication cables gives the most durable protection against
moisture and corrosion damage, and provides mechanical protection of the
insulation. Chemical lead, 1% antimonial lead, and arsenical lead are
most commonly employed for this purpose.
Sheet. Lead sheet is a construction material of major
importance in chemical and related industries because lead resists attack
by a wide range of chemicals. Lead sheet is also used in building
construction for roofing and flashing, shower pans, flooring, x-ray and
gamma-ray protection, and vibration damping and soundproofing. Sheet for
use in chemical industries and building construction is made from either
pure lead or 6% antimonial lead. Calcium-lead and calcium-lead-tin alloys
are also suitable for many of these applications.
Pipe. Seamless pipe made from lead and lead alloys is readily
fabricated by extrusion. Because of its corrosion resistance and
flexibility, lead pipes finds many uses in the chemical industry and in
plumbing and water distribution system. Pipe for these applications is
made from either chemical lead or 6% antimonial lead.
Solders in the tin-lead system are the most widely used of all
joining materials. The low melting range of tin-lead solders makes them
ideal for joining most metals by convenient heating methods with little
or no damage to heat-sensitive parts. Tin-lead solder alloys can be
obtained with melting temperatures as low as 182 °C and as high as 315 °C.
Except for the pure metals and the eutectic solder with 63% Sn and 37%
Pb, all tin-lead solder alloys melt within a temperature range that
varies according to the alloy composition.
Lead-base bearing alloys, which are called lead-base babbitt
metals, vary widely in composition but can be categorized into two
- Alloys of lead, tin, antimony, and, in many instances, arsenic
- Alloys of lead, calcium, tin, and one or more of the alkaline
Ammunition. Large quantities of lead are used in ammunition for
both military and sporting purposes. Alloys used for shot contain up to
8% Sb and 2% As; those used for bullet cores contain up to 2% Sb.
Terne Coatings. Long terne steel sheet is carbon steel sheet
that has been continuously coated by various hot dip processes with
terne metal (lead with 3 to 15% Sn). Its excellent solderability and
special corrosion resistance make the product well-suited for this
Lead foil, generally known as composition metal foil, is
usually made by rolling a sandwich of lead between two sheets of tin,
producing a tight union of the metals.
Fusible Alloys. Lead alloyed with tin, bismuth, cadmium,
indium, or other elements, either alone or in combination, forms alloys
with particularly low melting points. Some of these alloys, which melt
at temperatures even lower than the boiling point of water, are referred
to as fusible alloys.
Anodes made of lead alloys are used in the electrowinning and
plating of metals such as manganese, copper, nickel, and zinc. Rolled
lead-calcium-tin and lead-silver alloys are the preferred anode
materials in these applications, because of their high resistance to
corrosion in the sulfuric acid used in electrolytic solutions. Lead
anodes also have high resistance to corrosion by seawater, making them
economical to use in systems for the cathodic protection of ships and