ASTM A354 is an ASTM International

ASTM International

ASTM International, known until 2001 as the American Society for Testing and Materials , is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services...

 standard that defines chemical and mechanical properties for alloy steel bolts, screw

Screw

A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...

s, studs

Threaded rod

A threaded rod, also known as a stud, is a relatively long rod that is threaded on both ends; the thread may extend along the complete length of the rod. They are designed to be used in tension...

, and other externally threaded fastener

Fastener

A fastener is a hardware device that mechanically joins or affixes two or more objects together.Fasteners can also be used to close a container such as a bag, a box, or an envelope; or they may involve keeping together the sides of an opening of flexible material, attaching a lid to a container,...

s. It is officially titled: Standard Specification for Quenched and Tempered Alloy Steel Bolts, Studs, and Other Externally Threaded Fasteners.

This is a standard set by the standards organization ASTM International

ASTM International

ASTM International, known until 2001 as the American Society for Testing and Materials , is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services...

, a voluntary standards development organizations that sets technical standards for materials, products, systems, and services.

Mechanical properties

This standard defines the properties for fasteners up to 4 inches in diameter. They are not to be used in applications where they are tensioned to more than 50% of their tensile strength. In those applications structural heavy hex bolts are to be used, as defined by ASTM A490

ASTM A490

ASTM A490 and ASTM A490M are ASTM International standards for heavy hex structural bolts made from alloy steel. The imperial standard is officially titled Standard Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength, while the metric standard is titled...

, even though they have the same strength.

Head markings and mechanical properties

Head marking	Grade	Nominal size range [in]	Proof strength [ksi]	Yield strength (min) [ksi]	Tensile strength (min) [ksi]	Core hardness [Rockwell]
	Grade BC	–2- (inc.)	105	109	125	C26–36
		2-–4	95	99	115	C22–33
	Grade BD	–2- (inc.)	120	130	150	C33–39
		2-–4	105	115	140	C31–39

Recommended nuts

The standard also specifies what nuts are recommended for use with the defined fasteners. Note that nuts of a greater strength can also be used.

Fastener grade & surface finish	Nut grade & style
BC; plain or a coating of insufficient thickness to require over-tapped nuts	C; heavy hex
BC; zinc-coated or a coating that requires over-tapped nuts	DH; heavy hex
BD; all finishes	DH; heavy hex