• studbolts and fasteners
  • studbolts and fasteners
  • nuts fasteners


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.

Products Overview


studbolts

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

Bolt Nut Mechanical Properties
Grade Bolt Spec Material Grade Nut Spec Temperature Ratings Service Environment Nominal Stud Size (in) Yield Strength Tensile Strength
KSI Mpa KSI Mpa
B5 ASTM A193 AISI 501 Any ASTM A194 -50 to 1200°F
(-45 to 649°C)
High Temperature Service 1/4 thru 4 80 550 100 125
B6 AISI 410 Any -50 to 900°F
(-45 to 482°C)
1/4 thru 4 85 585 110 758
B7 CrMo Alloy Steel AISI 4140, 4142 or 4105 2H, 4, 7 or 8 1/4 thru 2 1/2 105 720 125 862
Over 2 1/2 thru 4 95 655 115 793
Over 4 thru 7 75 515 100 690
B7M 2HM, 4M, 7M, 19, 8M 1/4 thru 2 1/2 80 550 100 690
Over 2 1/2 thru 4 80 550 100 690
Over 4 thru 7 75 515 100 690
B8 Class 1 AISI 304 8 Cryogenic to 1500°F (815°C) All 30 205 75 515
B8 Class 2 to 3/4 100 690 125 862
Over 3/4 to 1 80 550 115 793
Over 1 to 1 1/2 50 345 100 690
B8M Class 1 AISI 316 All 30 205 75 515
B16 CrMoVa Alloy Steel 4, 7 or 8 -50 to 1100°F
(-45 to 593°C)
1/4 thru 2 1/2 105 720 125 862
Over 2 1/2 thru 4 95 655 110 758
Over 4 thru 7 85 585 100 690
307 Grade A ASTM A307 Carbon Steel Grades A, B, C, D, DH, DH3 ASTM A563 Amb. to 450°F (232°C) 60 KSI (414 Mpa) Tensile Strength   - - 60 414
307 Grade B 36 248 60-100 414-690
L7 ASTM A320 CrMo Alloy Steel AISI 4140, 4142 or 4105 4 or 7 ASTM A194 -50 to 1100°F
(-45 to 593°C)
Low Temperature Service 1/4 thru 2 1/2 105 720 125 862
L7M 7M 1/4 thru 1 1/2 80 550 100 690
L43 NiCrMo Alloy Steel AISI 4340 4 or 7   1/4 thru 4 105 720 125 862
L1 Low Carbon Boron 4 or 7   1/4 thru 1 105 720 125 862
B8 Class 1 AISI 304 8 Cryogenic to 1500°F
(815°C)
All 30 205 75 515
B8 Class 1A All 30 205 75 515
B8 Class 2 3/4 and under 100 690 125 862
Over 3/4 to 1 80 550 115 793
Over 1 to 1 1/4 65 450 105 720
1 1/4 to 1 1/2 50 345 100 690
B8M Class 2 AISI 316 3/4 and under 95 655 110 758
Over 3/4 to 1 80 550 100 690
Over 1 to 1 1/4 65 450 95 655
1 1/4 to 1 1/2 50 345 90 620
Type 1,2,3 ASTM A325   2 or 2H/C3, D, DH, DH3 ASTM A194 or A563 Ambient to 650°F
(343°C)
120/105 KSI Min. Tensile 1/2 to 1 92 634 120 827
Over 1 to 1 1/2 81 558 105 720
Grade BC ASTM A354   C3, D, DH, DH3 ASTM A563 Quenched and Tempered 1/4 to 2 1/2 109 752 125 862
Over 2 1/2 99 683 115 793
Grade BD   1/4 to 2 1/2 130 896 150 1034
Over 2 1/2 115 793 140 965
Type 1 ASTM A449   Ambient to 650°F
(343°C)
1/4 to 1 92 634 120 827
  Ambient to 700°F
(371°C)
Over 1 to 1 1/2 81 558 105 720
Ambient to 650°F
(343°C)
Over 1 1/2 to 3 58 400 90 620
Grade 660 ASTM A453     ASTM A453 -50 to 1000°F
(-45 to 538°C)
High Temperature Service A, B and C 85 585 130 896
Grade 651       Class A (3 and Under) 70 483 100 690
      Over 3 0 414 100 690
      Class B (3 and Under) 60 414 95 655
      Over 3 50 345 95 655
Grade 662       Class A 85 585 130 896
Grade 665       Class B 80 550 125 862
      Class A 120 827 170 1172
      Class B 120 827 155 1069
Grade 1 ASTM A490   DH, DH3, 2H ASTM A563 or A194     1/2 to 1/2 130 896 150-170 1034-1172
Grade 2         1/2 to 1 130 896 150-170 1034-1172
Grade 3         1/2 to 1 1/2 130 896 150-170 1034-1172
B21, 23 & 24 CL1 ASTM A540     ASTM A540 Ambient to 700°F
(371°C)
Special Applications 1/4 to 4 150 1034 115-165 793-1138
B21, 23 & 24 CL2     1/4 to 4 140 965
B21-24 CL3     1/4 to 6 130 896
B21, 23 & 24 CL4     1/4 to 6 120 827
B21, 23 & 24 CL5     1/4 to 2 105 720
    2 1/8 to 8 100 690
Grade 1 SAE J429   2 SAE J995   Bolts, Screws, Studs 1/4 to 1 1/2 36 248 60 414
Grade 2   2   1/4 3/4 57 393 74 510
Over 3/4 to 1 1/2 36 248 60 414
Grade 4   2, 5   1/4 to 1 1/2 100 690 115 793
Grade 5   5, 8            
Grade 7   5, 8            
Grade 8   8            

——— Click here to reveal the entire table ———

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 and Petrochemical sectors..

b7 stud bolts
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.
b7 stud bolts
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.

b7 stud bolts
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.

b7 stud bolts
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.

b7 stud bolts
ASTM A193 Grade B8T 18-8 grade of stainless with additional element of Titanium. Same as type 321 Stainless Steel.

b7 stud bolts
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.

b7 stud bolts

FASTENERS WE SUPPLY

fasteners
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.

materials codes
Delivery condition codes are also relatively common, the most common being:
codes
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.

HEX BOLTS
Carriage and Timber bolts have no drive, and machined threads for use with a nut.

carriage bolts
socket products
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 drawing
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.

NUTS
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.

flat head screws
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.
oval head screws

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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