Welded Steel Tubing Glossary

SAE 4130 is a steel grade containing the alloying elements of chromium and molybdenum to help achieve higher strength levels than 1020 carbon steel without increasing the carbon content or wall thickness. For a listing of expected chemical and mechanical properties expected with 4130 steel, please visit our 4130 ERW Tubing page on our website.

Aluminized steel is steel that has been coated on both sides with an aluminum silicon alloy. Aluminized steel has a unique combination of properties possessed neither by carbon steel nor by aluminum alone. Aluminized steel shows a better behavior against corrosion and is used in various application where heat resistance is critical. For a listing of standard tubing sizes and gauges that Valmont produces in an aluminized finish, please visit our Steel Tubing Product Catalog. Valmont produces welded aluminized tubing that meets ASTM specification A787 Type 1.

ASTM is the abbreviation for the American Society for Testing & Materials which is the governing body that publishes specifications that cover the ordering of steel, types of testing required and types of tubing produced among others. The ASTM website has a complete listing of specifications that you can search for more information. For a full listing of ASTM specifications that Valmont produces welded steel tubing to, please click here.

ASTM A53 specification covers seamless and welded black and hot-dipped galvanized steel pipe in NPS (Nominal Pipe Sizes). Tubing produced to this specification is typically used for mechanical and pressure applications. Valmont produces tubing made to A53 Type E (electric resistance welded). To view a listing of round OD sizes produced to ASTM A53, please view the Steel Tubing Product Catalog on this website.

ASTM A135 specification covers electric resistance welded steel pipe that is used to convey gas, vapor or liquid. Hydrostatic testing may or may not be required depending upon customer requirements. Two different grades are specified - Grade A and Grade B under A135. The required grade should be specified at time of quotation or order placement. To see a full listing of steel tubing sizes that Valmont produces to meet ASTM A135 or to sort by a particular OD size, please visit our Steel Tubing Product Catalog.

ASTM A252 specifications covers welded and seamless steel pipe piles. Valmont produces 12.375", 14.00" and 16.00" OD tubing to this specification using as submerged arc welded tubes. ASTM A252 is standardly produced to three different grades (Grade 1, Grade 2, Grade 3) with differing yield and tensile strengths depending upon the grade. Please visit our Steel Tubing Product Catalog for a complete listing of OD sizes and the corresponding ASTM specifications for those sizes.

ASTM A268 is a specification covering stainless steel tubing used in high temperature applications and where corrosion resistance is importance. Valmont produces a limited range of sizes that conforms in a stainless 409 chemistry. Please contact one of our knowledgeable sales team members by calling 1-800-825-6668 or send an email to tubing@valmont.com to inquire about our specific capabilities.

ASTM A500 is a specification for cold formed welded and seamless carbon steel structural tubing. Rounds and shapes such as square and rectangle are covered under this specification. Valmont produces electric resistance welded structural tubing that meets ASTM A500. Available in different grades (Grade A, B, C or D), it is important for the grade to be specified at time of quotation or order placement or the corresponding yield and tensile strength requirement for an application. For a complete listing of sizes produced to ASTM A500, please see our Steel Tubing Product Catalog.

ASTM A513 specification covers electric resistance welded carbon and alloy tubing for use as mechanical tubing. Valmont produces three types of tubing covered under A513:
Type 1a: As welded from hot rolled steel
Type 1b: As welded from hot rolled pickled & oiled steel
Type 2: As welded from cold rolled steel

In general, A513 will provide tighter tolerances than other ASTM specification such as A500 and A135. For a complete listing of OD sizes standardly produced to A513 by Valmont, please visit our Steel Tubing Product Catalog.

ASTM A787 specification covers round, square, rectangle and special shape electric resistance welded tubing that is zinc-coated after welding (hot dipped galvanized) or coated in coil form (galvanized, aluminized, galvannealed, zinc-aluminum-magnesium). Valmont, as a standard, produces mechanical carbon tubing to the following types:
Type 1: aluminized
Type 2: galvanized
Type 3: post hot dipped galvanized
Type 4: galvannealed
Type 6: zinc-aluminum-magnesium alloy coating

For a complete listing of standard sizes produced by Valmont Tubing to ASTM A787, please visit our online Steel Tubing Product Catalog.

ASTM A847 specification covers cold-formed welded and seamless high-strength, low-alloy round, square, rectangular, or special shaped structural tubing where high strength and enhanced atmospheric corrosion resistance are required. Weathering steel is the most commonly referred to name given to this type of steel.ASTM A606 is a commonly ordered chemistry for this tube specification. To see the full listing of sizes standardly produced to ASTM A847, please visit our Steel Tubing Product Catalog.

ASTM A1046 is the specification for steel sheet produced with a zinc-aluminum-magnesium alloy coating. Produced with different coating thicknesses, ASTM A1046 steel is used frequently in applications requiring corrosion resistance and painting. For more information on testing results of the corrosion resistance and on tubing sizes that Valmont produces to ASTM A1046, please visit our Zinc-Aluminum-Magnesium Tubingpage.

Steel is classified as carbon steel when its properties are defined by the various percentage of carbon without substantial amounts of other alloying elements. As carbon content increases, the steel becomes harder and stronger while the ductility of the steel decreases. Valmont produces welded carbon steel chemistries that include 1006, 1008, 1010, 1015, 1020, 1021, 1026 and 1030. Please visit the Finishes & Chemistries page for additional steel chemistries available.

A Charpy test, also known as the Charpy v-notch test, is a high strain test that determines the amount of energy absorbed by a sample of material during fracture. A free swinging pendulum is allowed to strike and break a notched sample. The position of the pendulum before and after the pendulum swings is compared. The energy absorbed is a measure of the the impact strength or notch toughness. ASTM standard E23 outlines the testing requirements.

Chemical properties are the mimimum and maximum limites of chemical elements as established by ASTM and SAE specifications.

Steel coils are sheets of steel that have been wound up by a steel mill. Large coils are slit or cut down to smaller widths desired in order to produce tubing. Once unwound, the flat coil is then formed to produce the mechanical tubing that Valmont produces.

Colled rolled steel is hot rolled sheet that has been cold reduced. Cold rolled steel provides tighter wall thickness tolerances and better surface condition than hot rolled steel. For a listing of standard tubing sizes and gauges that Valmont produces in a cold rolled finish, please visit our Steel Tubing Product Catalog. Valmont produces welded cold rolled tubing that meets ASTM specification A513 Type 2.

A test performed that exerts compressive force that is perpendicular to the diameter of the tube that is placed on end.

A secondary cold working process done to ERW tubing in order to obtain a special shape or tighter OD, ID, or wall thickness tolerances. An intermediate and less costly option to DOM would be to order ERW tubing to tighter than standard A513 tolerances. Please contact Valmont for specific options that can be offered. For a listing of standard tubing sizes and gauges produced by Valmont, please visit our Steel Tubing Product Catalog.

Eddy Current testing is a non-destructive testing method that utilizes an eddy current flow to detect a discontinuity in the weld area of the tubing.

Elongation is the amount of permanent extension in the vicinity of the fracture in a tension test. It is expressed as a percentage of the original gauge length.

Electric resistance weld tubing (ERW) is a method of tubing production where slit coils of steel are put through a gradual cold forming operation until the two edges of the steel are joined together in a tubular form. The heat for the continuous weld is generated at the seam by the resistance to the flow of electric current applied through an induction coil. Valmont produces round ERW tubing in sizes up to 12.75" OD along with square and rectangle sized tubing up to 6.00". For a complete listing of sizes that Valmont produces, please visit our Steel Tubing Product Catalog.

Finish refers to the type of surface and end condition desired in the finished product to suit the customer's need. Common finishes that Valmont produces tubing to include: hot rolled (HR), hot rolled pickled & oiled (P&O), cold rolled (CR), cold rolled matte, cold rolled bright, aluminized (AL), galvanized (GAL), hot dip galvanized (HDG), galvalume, weathering steel, along with 409 stainless (SS). Finish capabilities will vary by size. For a complete listing of tubing sizes produced along with our standard finishes available for each size, please visit our Steel Tubing Product Catalog.

A destructive test performed that tests the weld suitability of a piece of tube when it is expanded over a cone at various degrees of expansion.

Flash control refers to the different limits that the flash left from the ID weld bead can be controlled to during the ERW tube production process. For example, flash control to .015" means that the maximum ID weld bead that can remain is .015". Flash control requirements will vary by end use application. When placing a request for quote and order, it is important for the customer to make mention of the flash control requirements so that the tubing can be produced accordingly to those requirements.

"Flash in" refers to when the flash from the weld is left on the inside of the tubing and is not removed or controlled during the ERW tube production process. If flash is required or not, please make mention of that at the time of quotation and order placement.

A destructive test performed in the tube production process where a sample tube is flattened to a specified height. The weld is positioned at a predetermined location. Examination is made during the test for signs of cracking.

Refers to the thin layer of zinc finish that is applied to steel. Galvanized steel is used in applications where rust resistance is needed. It is identified by a crystalization patttern on the surface called "spangle". Galvanized tubing can be supplied in two ways: "pregalvanized" meaning that the steel is galvanized at the steel mill or as "hot-dipped galvanized" meaning that the tubing is produced from a hot rolled steel and then hot dipped after welding. For a listing of standard tubing sizes and gauges that Valmont produces in galvanized and hot-dip galvanized finishes, please visit our Steel Tubing Product Catalog. Valmont produces welded galvanized tubing that meets ASTM specification A787 Type 2 and Type 3.

A measurement of wall thickness of the steel. The Birmingham Wire Gauge terminology is commonly used in the tubing industry. For each gauge, there is a corresponding wall thickness to match that. For example an 18 gauge can also be referred to .049" wall thickness. For a complete listing of standard tubing sizes and gauges/wall thicknesses produced for that size, please refer to our Steel Tubing Product Catalog.