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

STUDBOLT GRADES WE SUPPLY

• B7 STUDBOLTS
• B16 STUDBOLTS
• B8 STUDBOLTS
• B8M STUDBOLTS
• B8C STUDBOLTS
• B8T STUDBOLTS
• L7 STUDBOLTS

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 and Petrochemical sectors..

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
ASTM A193 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
ASTM A193 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.

ASTM A193 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 B8M spec.

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 columbium.

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 temperature service.

FASTENERS WE SUPPLY

• FASTENERS
• MATERIAL GRADES
• HEX BOLTS
• CARRIAGE BOLTS
• SOCKET PRODUCTS
• NUTS
• MACHINE SCRES

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 application designation.

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 being:

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 bolts.

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 wrench.

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
Machine screws have machine threads for use with a nut or in a tapped hole. Also referred to as a stove bolt.

Pan Heads
Pan heads are slightly rounded with short vertical sides. Phillips drives are X shaped for a phillips screw driver.

Flat Heads
Flat heads are countersunk (cone shaped under the head) with a flat top. Slotted drives are simple slots for a flat bladed screw driver.


Oval heads 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

Studbolts

Stainless Steel & C/S

Hex Head

Fasteners

Nuts

All Sizes & Materials

Washers

To Suit any fitting

8.8

High tensile

Coated Fasteners

Painted / Galvanised