When selecting fastener materials for flange connection, factors such as pipe operating pressure, operating temperature, media type, and Gasket type should be considered.

The type of gasket, as well as the operating pressure and operating temperature, directly impose requirements on the strength of the fastener material. For example, the flange connection of a low-pressure, highly toxic medium pipe sealed with a wound gasket, although the operating pressure and temperature of the pipe are not high, because the specific pressure required to form the wound gasket into the initial seal is large, thereby The fasteners are required to bear a large load, and therefore, in this case, the fastener is required to be made of a high-strength alloy steel material.

Alloy steel studs should be made of high-quality steel. That is, the material grade should be followed by the letter A, such as 35CrMoA, 25CrMoVA.

Depending on the type of construction, bolts can be divided into hexagonal bolts and Stud Bolts (also known as studs), while stud bolts are divided into two types: wire and non-wire.

Hex head bolts: often used with flat welded flanges and non-metallic gaskets for milder operation. Common materials for hexagon bolts are BL3 or Q235B;

Stud Bolt: It is often used in conjunction with a butt weld flange under severe operating conditions. Among them, because the wire-type stud bolt has no change in cross-sectional shape, its load-bearing capacity is strong. The non-passing type studs are relatively weak in carrying capacity.

The nut material is often determined by the bolt material to which it is mated, and these combinations are specified in the general standard. Under normal circumstances, the nut material should be slightly lower than the bolt material, and ensure that the hardness of the nut is lower than the bolt hardness by about HB30.

Stud bolts, a term used for cut-to-length all thread rod, are used for: bolting together flanges, anchor bolting, as well as general fastening. 
Bangdong is a stud bolt distributor, offering stud bolts in carbon, stainless, along with several special alloys. With stud bolt diameters ranging from 1/2" to 4", Bangdong can provide the stud bolts required for virturally any project.

INVENTORY

Bangdong Supply stocks Grade B7 Stud  from 1/2" - 2" diameter in: Plain (black) finish, Teflon Blue, and Cad Plating.  Bangdong also stocks B8 and B8M stud bolts from ¼ - 1-1/2".  we can also provide larger stud bolts, stud bolts made from different materials (B8, B8M, Alloy 20, Monel, Hastelloy, Inconel, Titanium, etc), as well as different coatings. While many of the larger diameter items can be made available for a next-day delivery, some of the special alloys and coatings may be subject to a longer lead time.  The table below shows a look at not just the stud bolts bandong has in inventory, but what bangdong is capable of providing.

THREAD PITCH

Thread pitch refers to the steepness of the angle of thread, which is measured in threads per inch.  Thread Pitch Chart shows the unified screwed thread for coarse and fine thread, as well as the thread pitch for stud bolts. Stud Bolt covered under the A193 or A320 ASTM Specifications utilize 8UN for all diameters 1" and above, meaning there are 8 threads per inch for these sizes. All other materials should be specified by the purchaser unless noted in the ASTM spec given.

LENGTH

Length can be measured one of two ways, either overall length (OAL) or first useable thread to first useable thread (FTF). Industry standard and  stock is measured OAL. To find FTF measurement from OAL, simply subtract a quarter of an inch.

MATERIAL

Stud bolts can be made from many different grades of material, but the most common materials are listed below.  The A193 and A320 pages provide the chemical and mechanical properties of these material grades below.  

CARBON STEEL

A193 B7 – This is the most common grade for which stud bolts are produced.  B7 is a Chrome-moly, Alloy steel that is made to AISI 4140/4142, and it is quenched and tempered.

A193 B7M – The [M" here stands for Modified (heat treated) B7 material

A193 B16 - Chrome-moly-vanadium, Alloy steel, AISI 4140/4142 quenched and tempered

A320 L7 - AISI 4140/4142 quenched and tempered Alloy steel

A320 L43 - AISI 4340 quenched and tempered Alloy Steel

STAINLESS STEEL

A193 B6 – Heat treated 410 stainless (410HT)

A193 B8 – Produced to grade AISI 304, carbide solution treated, standardly available in class 1

A193 B8M – Produced to grade AISI 316, carbide solution treated, standardly available in class 1

A193 B8C- Grade 347 stainless material

A193 B8T – Grade 321 stainless material

A320 B8 - Produced to grade AISI 304, carbide solution treated, standardly available in class 1

A320 B8M - Produced to grade AISI 316, carbide solution treated, standardly available in class 1

RELATED HARDWARE

This chart shows the nuts and washers that accompany the stud bolts outlined here.  These items are required for proper installation.

COATING AND PLATING STUD BOLTS

Stud bolts are most commonly available with a plain finish, which is also referred to as Black.  However, there are also numerous applications that call for coating/plating, with the most common Teflon Blue coating.  Teflon, or Xylan, coating provides for increased corrosive resistance, which is favorable that require increased corrosion resistance as well as the strength of B7 material.

We have below Bolts & Nuts :

A193 GR b7 Stud Bolt

Fasteners Stud Bolt 
Stud Bolts 
Heavy Nuts 
Stud Bolts With 2 Nuts 
Hex Bolts