Glossary

AIS

AIS, (American Iron & Steel Compliance)  is a partnership between the U.S. Environmental Protection Agency, (EPA) and States that provide loans via the CWSRF, (Clean Water State Revolving Fund) and/or the DWSRF, (Drinking Water State Revolving Fund). 

States receiving this assistance must use iron and steel products that are produced here in the United States. This requirement applies to projects for the construction, alteration, maintenance, or repair of a public water system or treatment works.

AISI

AISI is an acronym for American Iron and Steel Institute. AISI members make over 80% of the steel produced in North America. AISI sets standards for steel companies around the U.S. in a push to improve the industry.

ASTM

ASTM International, (formerly known as the American Society for Testing and Materials), is a global organization that develops and publishes voluntary consensus standards for a wide range of materials, products, systems, and services. The purpose of these standards is to improve performance and safety.

Acme Thread

An Acme thread is a type of American screw thread with a 29-degree angle that’s a cross between a square and V-shaped thread.  Acme threads are stronger and more durable than square threads and can withstand heavier loads. They’re also easier to manufacture and operate better in environments with dirt and debris.

All Thread

An All thread is a metal rod that has been threaded for its entire length. All thread is used for general purpose threaded fastening systems. All thread can be Rods, (12” or longer in length) or Studs, (less than 12” in length). 

Alloy Steel

Alloy steel is steel that is alloyed (mixed) with a variety of elements to improve its mechanical properties. Common alloyants include manganese (the most common), nickel, chromium, molybdenum, vanadium, silicon, and boron. Improved properties in alloy steel (as compared to carbon steel) are strength, hardness, toughness, wear resistance, corrosion resistance, hardenability, and hot hardness.

Aluminum

Aluminum is a lightweight corrosion-resistant, non-magnetic, ductile material commonly used in a wide range of applications including soda cans, kitchen foil, aircraft fuselage, and automobile frames

Anchor Bolt

An anchor bolt  is used to attach objects or structures to concrete. Anchor bolts consist of a threaded end, to which nut and washer can be attached for the external load. Usually, anchor bolts are bent at one end; however, they also can be straight. Anchor bolts are extensively used on all types of projects.

B7 Steel

B7 Steel is an Alloy steel that has been heat treated, quenched and tempered resulting in a higher strength and hardness. B7 steel is designed for bolting heavy joints, pressure vessels, and valves.  

Black Oxide

Black oxide, also known as gun bluing or blackening, is a chemical conversion coating that's applied to ferrous metals, stainless steel, copper, zinc, and other materials. The coating is created by 

immersing the material in an alkaline salt solution heated to around 285°F, which causes a reaction between the iron in the metal and the hot oxide bath. This reaction produces magnetite (Fe3O4) on the surface of the material, leaving a black coating.

Brass

Brass is a corrosion resistant alloy made of copper and zinc. It has good electrical and thermal conductivity and is often used also used where a more pleasing aesthetic is required because of its’ gold-like appearance.

Buy American Act (BAA)

The Buy American Act (BAA) of 1933, requires federal agencies to prioritize the purchase of domestic products and materials for contracts over a certain amount. The threshold is currently $10,000, but can be raised during emergencies. The BAA applies to goods, such as articles, materials, and supplies, that are purchased for public use. 

Chamfer

A chamfer is a transitional edge between two faces of an object. It is created by removing the corner or sharp edge at the end of a Rod or Stud, (often at a 45° angle).

Chromate

Chromate is a chemical coating that is applied during the Zinc plating process. Please see Zinc Electro Plating.

Coarse Threads

A coarse thread is primarily defined by the thread pitch, (the distance between two adjacent threads) and are a group of products also known as UNC, (Unified National Coarse).  Coarse threads are the most popular thread group produced by AATP. 

Coupling Nut

A Coupling Nuts, (also known as an Extension nut), is a longer than normal threaded nut used for joining two threads together. The outside of the Coupling Nut is usually hex, giving the ability to hold, tighten or loosen with a wrench.

Cut Thread

A cut thread (also known as a machined thread) is created by removing material from a bar or blank to produce a thread profile. This process can be done using a single point tool, threaded dies, thread mills, or a tap to achieve the desired thread pitch. Please note that AATP do not manufacture products with a cut thread. Our manufacturing process uses a roll thread, (please see Roll Threading).

DFARS

DFARS, (Defense Acquisition Regulations System), outlines the US Government requirements for directly or indirectly supplying the Department of Defense. These requirements range from Audit and Assessment Control, Internal Process Control, Cybersecurity and Counterfeit electronic parts clauses to a more basic requirement that materials must originate from a specific list of countries. This list was originally based exclusively on NATO countries but has since been expanded to include additional countries.

Double End Rods and Studs

Double ended Rods and Studs have threads at both ends and a center section that is unthreaded. The length of threads can either be equal or unequal and they can be a left hand or right-hand thread. All AATP double end products are Specials.

Eye Bolt

An Eye Bolt is a bolt that has one end which is closed or open ring with a threaded section at the end. The threaded end is used to firmly attach a securing eye to a structure, so that ropes or cables may either be tied to it or passed through it.

F1554

F1554 references material specification ASTM F1554. This material was developed by the American Society for Testing and Materials (ASTM) for use in construction related projects such as Freeway signs, Street Lights and Traffic signals and replaces the former ASTM A307 Grade C material specification.  At AATP F1554 meets the material specification ASTM F1554 Grade 55 (S1), which is a weldable grade of material.

Fine Thread

A Fine Thread is primarily defined by thread pitch (the distance between two adjacent threads), this group of products is also known as UNF (Unified National Fine).  They have a greater number of threads per inch than UNC. 

GR8HT™

GR8HT™ ROD and GR8HT™ STUD are the brand names given to AATP’s range of Hight Tensile Threaded Rods and Studs certified to ASTM A354 Grade BD.

Galvanizing

Galvanizing is the process of applying a thick coating of Zinc Plating, please see Hot Dipped Galvanizing.

Grade 8

Grade 8 is a grade of High Strength steel from the SAE J429 Standard. It is almost identical in chemical and mechanical content to ASTM A354 Grade BD and offers the same tensile and yield strengths.

Grade BD

Grade BD is a grade of High Strength steel from  the ASTM A354 Standard. It is almost identical in chemical and mechanical content to SAE J429 Grade 8 and offers the same tensile and Yield strengths but is far more readily available.

Heat Treatment

Heat Treatment describes the process used to alter the physical properties of a material. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, in order to achieve a hardening or softening of material. 

Hot Dip Galvanizing (HDG)

Hot Dip Galvanizing, also known as HDG is the process of dipping steel products into a vat containing molten zinc. This type of Zinc Plating is inherently simple which provides an advantage over other corrosion protection method, and it generally provides a much thicker coating.  Please also see Mechanical Galvanizing.

J-Bolt

A J-Bolt is a bolt that is in the shape of the letter “J”. J-Bolts are most commonly used to suspend electrical wiring and sheet metal from wooden structures as well as to hold springs in the furniture industry.

Knurling

Knurling is a manufacturing process whereby a pattern of straight, angled, or crossed lines is cut or rolled into the material.

Lift

Threaded rod shipping on a “lift” refers to tubed All Thread rod, stacked and strapped to wooden blocks to raise or lift the goods off the ground by allowing a forklift to pick up from the side. 

Low Carbon Steel

Low Carbon steel, often referred to as mild steel, is the most common type of steel used for general purposes, in part because it is less expensive than other types of steel. Low carbon steel contains properties that work well in manufacturing a variety of goods.

Make and Hold Order

A “Make and Hold” order is a customer purchase order for multiple deliveries of the same item with delivery flexibility “built in”.  For example a customer uses 1,000 pieces a month and places an order for 6 months stock, (6,000 pieces). However, AATP gives the customer 12 months in which to consume them. 

Mechanical Galvanizing

Mechanical galvanizing (ASTM B695) is a process in which fasteners are tumbled in a barrel with a mixture of water, zinc powder, other chemicals, and glass impact beads. AATP does not offer this type of plating.

Metric

Metric is the European measurement system that is based on the power of ten. Examples would be, Lengths & Distances = millimeters, centimeters, meters and kilometers, i.e. Ten millimeters = a Centimeter. Ten Centimeters = a Decimeter. Ten Decimeters = a Meter. Ten Meters = a Dekameter. There are ten Dekameters to 100 meters and 1,000 meters to a Kilometer. 

Pallet

Pallet shipping refers to the transportation of goods using pallets as a standardized unit of loading and handling. A pallet is a flat, portable platform typically made of wood.

Passivation

Passivation is a chemical process that coats a material's surface to make it more resistant to corrosion. The process removes free iron particles from the material and creates a thin, protective layer of oxide. This layer prevents further oxidation and corrosion and can also improve the material's appearance.

Pitch Diameter

The Pitch diameter is a fundamental measurement of a screw, threaded hole, or tap and represents the diameter of an imaginary cylinder that passes through the thread at approximately halfway between the major and minor diameters.

REACH

Reach is a set of regulations that are part of the European Union's (EU) Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation. The regulation aims to protect human health and the environment from chemicals by requiring manufacturers to ensure their products are safe and provide detailed information on the substances they contain. Please also see Restriction of Hazardous Substances, (RoHS).

Restriction of Hazardous Substances

Restriction of Hazardous Substances generally referred to as RoHS, [pronounced Ro-Hass] pertains to the plating of steel products and aims to restrict certain dangerous substances commonly used in electronic and electronic equipment such as lead, cadmium, mercury, hexavalent chromium etc.

Rockwell Hardness

Rockwell Hardness is a measurement of hardness just as feet and inches is a measurement of height.  There are three commonly used scales of Rockwell hardness, A,B & C. or HRA, HRB & HRC. These designations are followed by a number, the higher the number the harder the material. 

• HRA applies to the hardness testing of thin steels. 
• HRB applies to the hard ness testing of Copper Alloys, soft Steels, Aluminum Alloys and malleable iron etc.
• HRC applies to the hardness testing of Steel, Hard cast irons, Titanium, deep case-hardened materials and all materials where the hardness is expected to exceed HRB100.

Roll Threading

Roll Threading is a process by which steel is extruded to form the threaded portion of a fastener, instead of being removed as in cut threading. So instead of cutting away material to produce a thread, the base material is passed through a set of thread rolling dies, it is this action that displaces the parent material and forms the threads.

Rounds

Rounds are pieces of unthreaded steel that have been straightened and cut to length.

SAE International

SAE International was initially established as the Society of Automotive Engineers and has evolved into an organization that sets specification standards for engineering professionals. 

Single-End Rods and Studs

Single-End Rods and Studs have threads at one end and the balance of the rod unthreaded and can be produced as either a right hand or left-hand thread. All AATP single end products are Specials.

Specials (SP)

Specials are parts that AATP manufactures to a customer’s specifications and are generally unique to that customer. These parts are made to order and typically would include left hand threads, (standard threads are right hand threads), non-standard lengths,   non-standard material and parts to a customer drawing. 

Stainless Steel

Stainless Steel refers to a steel that contains chromium (12% +) and is much more resistant to corrosion, rust and stain than Low Carbon steels. There are several different types of stainless steel. AATP produces products from SS304 (the most common) which is also known as 18-8 and also SS316, sometimes referred to as marine grade Stainless.

The primary difference between 304 Stainless and 316 Stainless is that 316 Stainless contains 2% molybdenum making it more resistant to corrosion caused by chlorides, such as sea water and de-icing salts. 

Studs

Studs are threaded rods that are less than 12 inches in length. (Threaded Rods that are 12 inches or longer in length are referred to as Rods). Studs can be “all thread” or threaded at one end, (Single end), or at both ends, (Double end).

Tensile Strength

Tensile strength, also known as ultimate tensile strength (UTS), is a material's maximum stress capacity before breaking or deforming when stretched or pulled. (See also Yield Stress).

Thread Classes

The term “Thread Class” describes the form and fit, (looseness or tightness of fit),  between an external thread and an internal thread.  

• For Inch threads there are three designations classes 1A, 2A and 3A. AATP produce low carbon steel parts with a 1A Class Thread before plating, and a 2A Class Thread on B7, SS304, SS316, GR8HT Rod, GR8HT Studs, Aluminum and Brass. 
• There two common designations for metric threads  6H/6g = General purpose. 6H/5g6g = Closer fit.
• Upper case = Internal Thread
• Lower case = External threads. 
• Smaller numbers indicate a tighter thread fit.

AATP produce metric parts with a 6g class of fit. We do not make metric parts with a 5g6g fit.

Thread Pitch

Thread pitch is the distance between the same point on two adjacent threads of a screw or nut. That distance corresponds to how far the fastener will “travel” when turned 360 degrees.

Thread Rolling

Please see Roll Threading

Thread Size Designations

Unified/Imperial/Inch size threads are described by the diameter followed by the  TPI, (Threads Per Inch). e.g.   A 1/2” Unified Coarse thread is 1/2”-13 as there are 13 threads for every inch of length, whereas as 1/2” Unified Fine thread  is 1/2”-20 as there are 20 threads for every inch of length.

Metric Thread sizes are described by the diameter in mm followed by the Thread Pitch, (the distance  between the same point on two adjacent threads). e.g. A 4mm thread is M4 x 0.7. as there is 0.7mm between each thread.

Please Note: Metric threads as standard are coarse. A Fine metric thread is available but tends to be manufactured to order.     

Threaded Rod

Threaded Rods are defined as straight rod that has been threaded and is 12 inches or longer in length. (Threaded Rods below 12 inches are referred to as Studs). AATP produces threaded rod up to 12 feet in length. Threaded rod can be all thread, double-end or single-end thread.

U-Bolt

A U-Bolt is a type of bolt shaped in the letter “U” with screw threads on each end. U-bolts can have either square or round shapes. U-bolts are often used to support water and gas pipes.

USS Flat Washer

USS Flat Washer is a thin plate (typically disk-shaped) with a hole (typically in the middle) that is normally used to distribute the load of a threaded as a screw or nut. Common materials include steel, stainless steel, and plastic.

V-Bolt

A V-Bolt is a bolt in the shape of the letter “V”. Each end on the V-bolt is threaded. V-bolts are most often used to hold pipes and telecommunication wires.

Wire Size Threaded Rod & Studs

Wire Size Threaded Rods & Studs are made from wire with a  diameter that is less than 1/4”. Small wire is designated with a number (0 through 12, with 0 being the smallest and 12 the largest diameters). Wire size Threaded Rods & Studs use that number plus the threads per inch, (TPI) to designate the diameter and thread pitch, i.e. 2-56 or 12-24.

Yield Stress

Yield stress, also known as yield point, is a material property that measures the minimum amount of stress required to make a material deform plastically and flow. It's the point at which a solid will transition from elastic to plastic behavior, and some of the deformation becomes permanent and irreversible. (See also Tensile Strength). 

Zinc Electro Plating

Zinc Electro Plating is where a thin Zinc coating is applied to finished products. Zinc’s excellent corrosion resistance in most environments’ accounts for its successful use as a protective coating in many exposure conditions. The plating process includes cleaning, rinsing and then bathing in a zinc solution where an electrical current is introduced, this helps to bond the zinc ions to the metal surface being plated. 

Zinc Plating is often applied with a Clear or Yellow Chromate, this adds an additional level of corrosion resistance to the Zinc plating. If yellow chromate is applied the resulting finish will have a rainbow or iridescent appearance with dominant yellow tones.