
Hex Nuts
Hexagon nuts in standard and heavy series for general and pressure bolting.
Materials: stainless, carbon, alloy steel and more, subject to enquiry
ASME B18.2.2
View ProductDouble-ended and fully threaded studs for flanged joints, pressure vessels and heavy equipment. Common configurations: full thread, equal thread both ends, reduced shank.

Double-ended and fully threaded studs for flanged joints, pressure vessels and heavy equipment. Common configurations: full thread, equal thread both ends, reduced shank.
A stud bolt is a headless fastener threaded on both ends or along its full length, used with two nuts in flanged and pressure joints. Studs are standard for flange bolting in oil, gas and power service because both nuts can be tightened and replaced independently.
| Product Name | Stud Bolts |
| Product Type | Studs |
| Material | Stainless steel, carbon steel, alloy steel, duplex, super duplex, nickel alloys, brass, titanium, high tensile (subject to enquiry) |
| Grade | B7, B7M, B16, B8, B8M, L7, 304, 316 |
| Size Range | Available as per customer specification |
| Head / Drive | Double-ended or fully threaded |
| Thread Type | Metric (ISO 261) or UNC/8UN (ASME B1.1) |
| Manufacturing / Dimensional Standard | ASTM A193 B7/B7M/B16/B8/B8M, ASTM A320 L7, ASTM A194 (nuts), ASME B18.31.2, ASME B16.5, DIN 975, DIN 976-1, DIN 938/939 (applicable standard confirmed against your order) |
| Finish / Coating | Plain, zinc plated, hot dip galvanized, black oxide, passivated, electro galvanized, nickel plated, or customer specified |
| Mechanical Properties | Per material grade and standard; see table below |
| Testing / Inspection | Dimensional, visual, thread, mechanical and chemical checks as agreed with the order |
| Certification | Material Test Certificate on request; EN 10204 3.1 where requested |
Standards commonly associated with Stud Bolts: ASTM A193 B7/B7M/B16/B8/B8M, ASTM A320 L7, ASTM A194 (nuts), ASME B18.31.2, ASME B16.5, DIN 975, DIN 976-1, DIN 938/939. The governing standard is confirmed against your purchase specification; not every standard is stocked or supplied in every size or grade.
Dimensions are manufactured according to the applicable dimensional standard and customer requirements. Share your drawing or size list for confirmation.
| Material | Typical grades | Standards |
|---|---|---|
| Stainless Steel | 304, 304L, 316, 316L, 321 | ASTM F593, F594, A193 B8/B8M/B6, A194 Gr 8/8M, A276, ISO 3506-1/-2 |
| Carbon Steel | Class 4.6, ASTM A307 Gr A / B, Class 8.8 / SAE Gr 5 | ASTM A307, A563, ISO 898-1/-2, SAE J429, DIN/ISO dimensional standards |
| Alloy Steel | B7, B16, L7, 4340, A354 BD | ASTM A193 B7/B7M/B16, A194 2H/4, A320 L7, A354 BD, A574, ISO 898-1 10.9/12.9 |
| Duplex Steel | S31803 / S32205, S32304 | ASTM A276, A479, A182 F51/F60, NACE MR0175 / ISO 15156 where specified |
| Super Duplex Steel | S32750, S32760, S32550 | ASTM A276, A479, A182 F53/F55, NACE MR0175 / ISO 15156 where specified |
| Nickel Alloys | Alloy 600 (N06600), Alloy 625 (N06625), Alloy 718 (N07718), Alloy 825 (N08825), Monel 400 (N04400) | ASTM B166, B446, B637, B425, B164, B865, B574, F467/F468 |
| Brass | C26000, C28000, C36000, C46400 | ASTM B16, B21, B134, F467/F468, DIN/ISO dimensional standards |
| Titanium | Grade 1, Grade 2, Grade 5, Grade 9, Grade 12 | ASTM B348, B381, F467/F468, ASME SB-348 |
| High Tensile | Class 8.8, Class 10.9, Class 12.9, SAE Gr 5 / Gr 8 | ISO 898-1/-2, ASTM A193 B7, A354 BD, A325, A490, SAE J429 Gr 5/8 |
General industry information. Availability of a given grade is confirmed at enquiry stage. See individual material pages.
| Grade | Tensile (MPa) | Yield (MPa) | Hardness |
|---|---|---|---|
| ASTM A193 B7 (≤2½ in) | 860 min | 725 min | 35 HRC max |
| ASTM A193 B7M | 690 min | 550 min | 99 HRB max |
| ASTM A193 B16 (≤2½ in) | 860 min | 725 min | 321 HBW max |
| ASTM A193 B8 / B8M Cl.1 | 515 min | 205 min | 96 HRB max |
| ASTM A193 B8 / B8M Cl.2 (≤¾ in) | 860 min | 690 min | – |
| ASTM A320 L7 | 860 min | 725 min | Impact tested |
Minimum or typical values per cited standards; they vary by grade, diameter, heat treatment and applicable standard.
| Finish | Notes |
|---|---|
| Plain | Uncoated; typical for stainless steel and non-ferrous |
| Zinc Plated / Electro Galvanized | Thin zinc layer for indoor and mild environments |
| Hot Dip Galvanized | Thick zinc coating for outdoor and structural use; allowances needed on mating threads |
| Black Oxide | Mild corrosion resistance with oil, low reflectivity |
| Passivated | Removes free iron from stainless steel to restore the passive film |
| Nickel Plated | Corrosion and wear resistance, appearance |
| Customer specified | Other coatings on request |
Typical process route for this product type (general information; actual route depends on size, material and order):
See the Quality page. Documentation scope is agreed at the quotation stage.
Stud Bolts can be quoted to your drawing, sample or specification, including non-standard sizes, lengths, threads, materials and finishes. Send details through the enquiry form.
Stud Bolts can be quoted in stainless steel, carbon steel, alloy steel, duplex, super duplex, nickel alloys, brass, titanium and high tensile grades, subject to size and standard.
Typical references are ASTM A193 B7/B7M/B16/B8/B8M, ASTM A320 L7, ASTM A194 (nuts), ASME B18.31.2, ASME B16.5, DIN 975, DIN 976-1, DIN 938/939. The governing standard is confirmed against your specification.
Size range depends on product, material and standard. Share diameter, length and quantity for confirmation.
Yes, to customer drawing or specification, subject to technical review.
Plain, zinc plated, hot dip galvanized, black oxide, passivated, electro galvanized, nickel plated or customer specified finishes.
Material Test Certificates, including EN 10204 3.1 where requested, can be requested with the order. Scope is agreed at quotation.

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Materials: stainless, carbon, alloy steel and more, subject to enquiry
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