With a wealth of knowledge in the fasteners and fixings
industry, we offer all our clients a level of service
second to none, ensuring they receive the right products,
on time, fit for purpose and for minimal outlay. We have
been supplying fasteners for a number of years now and can
supply all threads and all types of fasteners. We can also
supply or manufacture in any material, from Plastics &
Polymers through to Aluminium & Titanium Alloys, but
most commonly in Quality Assured Carbon Alloys, Stainless
Steels, and Nickel Based Superalloys & Heat Resisting
steels. If you just require regular deliveries or a more
urgent service for your sites critical plant outages or
shutdown events, we can provide the delivery solution to
suit your needs.
Studbolts are generally used in the Petrochemical and Oil & Gas industry for flange connections. The studbolt is a threaded rod with 2 heavy hexagon nuts, while the hex bolt has a head with one nut. Both the nuts and the head are six sided.
The material qualities for studs are defined in the different ASTM standards, and are indicated by Grade. Frequently used grades are A193 for thread rods and A194 for the nuts. ASTM A193 covers alloy and stainless steel bolting material for pressure vessels, Valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications. ASTM A194 covers a variety of carbon, alloy, and martensitic and austenitic stainless steel nuts. These nuts are intended for high-pressure or high-temperature service, or both. This specification includes fasteners intended for use in pressure vessels, valves, flanges, and fittings. Although this material is often available in national coarse (UNC) thread pitches, if being used in traditional applications, threads are specified 8 threads per inch (tpi) for diameters above one inch. ASTM A193 covers a number of other standard specifications not covered in this description including B5, B6, and B16.
Fastener Specifications & Details
For over 10 years, Specialised Engineering Products has been satisfying your studbolts and fastener requirements. We specialise in fasteners of every size, shape and material, and can even manufacture to your specific needs. Our sales team are here to help you and offer value added services tailored to your specific requirements.
STUDBOLT GRADES WE SUPPLY
We stock B7's in a variety of lengths,
and can supply cut-to-order studs
immediately in special sizes. SEP
supplies B7 studbolts both
individually and assembled with ASTM
A194 2H Heavy Hex Nuts. The ASTM A193
B7 stud is our most common fastener
for process piping applications in the
Oil & Gas
ASTM A193, Grade B16 - heat-treated chromium molybdenum
vanadium steel for high-pressure,
high-temperature service. It has the
same physical properties as B7 however added vanadium
allows it to hold it’s strength to 1100° F.
B8 Class 1
Grade B8 Class 1 studbolts are manufactured from 304 grade stainless steel and are carbine solution treated. They are non
magnetic, provide good corrosion resistance and offer 75,000
PSI tensile strength.
B8 Class 2
Grade B8 Class 2 studbolts are manufactured from 304 grade stainless steel, are carbine solution treated with the addition of strain hardening. Strain hardening is a cold working process
which increases physical properties meaning an increase from 75,000 PSI tensile strength the 90-000 - 125,000 PSI. They are non
magnetic, provide good corrosion resistance.
Grade B8M. These are similar to B8 fasteners
except with added Molybdenum. They offer better
corrosion resistance than B8. Hex Bolts,
studs and other fasteners are common to the
ASTM A193 B8C is 347 SS (UNS S34700). It
is a high-alloy austenitic stainless steel used
in extreme applications. It differs from
standard B8 with the addition of tantalum and
ASTM A193 Grade B8T 18-8 grade of stainless
with additional element of Titanium. Same
as type 321 Stainless Steel.
ASTM A320 Grade L7 Bolts, studs, and
other fasteners under the L7 grade have
the same chemical and physical
properties as B7. An additional
requirement is that a Charpy Test
at 150° F is needed. Such
fasteners are commonly used for low
FASTENERS WE SUPPLY
Our fasteners come in various sizes and
material types, varying from Hex Head
to Round Head, Zinc Plated to
Stainless Steel to Zirconium. We pride
ourselves on being able to supply any
fastener that you require, quickly and
at a very competitive price. Our sales
team are happy to take your call and
answer any questions you might have
regarding your fastener requirements.
Basic steel grade designations for
category 1 steels consist of a single
letter (designating application) then a
number signifying the mechanical
property (often yield strength)
dictated in the standard for that
For some application designations
another letter is included before the
property value, this number is used to
indicate any special requirements or
conditions. These additional letters
and values depend entirely on the
application of the steel and are
specified in the standard and far too
numerous to mention here.
Delivery condition codes are also
relatively common, the most common
Hex bolts have hexagonal heads and machine
threads for use with a nut or in a tapped hole.
These are allso known as hex cap screws or machine
Carriage and Timber bolts have no drive, and
machined threads for use with a nut.
Socket screws have an allen wrench drive.
Socket caps have a small cylindrical head
with tall vertical sides. Allen drives are
six sided recesses for use with an allen
Socket Flat Head Flat heads are countersunk
(cone shaped under the head) with a flat
top. Allen drives are six sided recesses
for use with an allen wrench.
Nuts have internal machine threads, for use
with machine thread bolts and screws. We can
supply all sizes and all materials and threads
to suit your requirements.
Machine screws have machine threads for use
with a nut or in a tapped hole. Also referred
to as a stove bolt.
Pan heads are slightly rounded with short
vertical sides. Phillips drives are X shaped
for a phillips screw driver.
Flat heads are countersunk (cone shaped under
the head) with a flat top. Slotted drives are
simple slots for a flat bladed screw
Oval heads are
countersunk (cone shaped under the head) with a
rounded top. Slotted drives are simple slots
for a flat bladed screw driver.
How To Correctly Measure A Studbolt
Studbolt length is defined in ASME B16.5 standard. The length in inches is equal to the effective thread length measured parallel to the axis, from the first to the last thread, without chamfers (points). The first thread is defined as the intersection of the major diameter of the thread with the base of the point.
Studbolts & Fasteners
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selection of products from SEP related to the Studbolts
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