Industrial Fasteners
Bolting and fasteners for flanged joints and structures — stud bolts, hex bolts, nuts, washers, anchor and U-bolts — to ASTM A193/A194/A320 and metric standards, in carbon, alloy, stainless and nickel grades.
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Each type links to grades, coatings, standards and a product-specific enquiry.
Bolts & Stud Bolts
B7 · full-thread / hexStud bolts and hex bolts for flanged joints and structures, to ASTM A193.
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Nuts
Heavy hex · 2H / 2HMHeavy hex and standard nuts to ASTM A194, matched to the bolt grade.
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Washers
Plain · spring · structuralPlain, spring and structural washers to suit the bolting assembly.
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Studs & Threaded Rod
Continuous threadContinuously threaded studs and rod in bolting and structural grades.
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Anchor Bolts
J / L / headedFoundation anchor bolts (J, L and headed) for structural fixing.
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U-Bolts
Pipe supportU-bolts for pipe support and clamping, sized to the pipe OD.
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| Parameter | Specification |
|---|---|
| Product | Bolting & fasteners (stud bolts, hex bolts, nuts, washers, anchor & U-bolts) |
| Dimensional standard | ASME B18.2.1 (bolts) · B18.2.2 (nuts) · B18.22.1 (washers) |
| Threads | UNC / 8-UN (ASME B1.1) · metric ISO 261 / 262 with ISO 965 tolerances |
| Class / grade | A193 B7 / B16 · A320 L7 / L43 · A194 nut grades · stainless property class (ISO 3506 / A193 B8 / B8M) |
| Size range | M6 – M64 / 1/4" – 4" (family envelope; per-product diameter, pitch & length confirmed) |
| Material specifications | ASTM A193, A194, A320, A307, A563, F593 / F594, F1554 (anchors) |
| Coatings | PTFE / xylan · hot-dip galvanised · zinc (coating system, thickness & thread allowance per order) |
| Documentation | EN 10204 3.1 / 3.2, PMI, TPI |
How it is made
Bolting is hot- or cold-forged and threaded — cut or rolled in the sequence qualified for the grade — from bar, then heat treated: alloy grades (B7, L7, B16) quenched & tempered; austenitic stainless (B8/B8M) solution treated (Class 1) or strain-hardened (Class 2). Nuts are hot-forged or machined and hardness-controlled to A194 by grade. Threads are cut or rolled to ASME B1.1 (UN) or ISO 261 (metric) with the specified tolerance class. Bolt and nut grades are matched for strength and hardness for the service, and coatings (PTFE, hot-dip galvanising, zinc) are applied with the thread allowance and friction factor stated where torque control matters.
Grades & materials
Representative bolting and fastener grades, with representative chemistry. Exact grade, class and condition are confirmed per order; availability is by verified capability — not every grade in every product, size and finish.
| Material family | Grades | UNS | Standard | Service |
|---|---|---|---|---|
| Alloy bolting | A193 B7 / B7M / B16 | — | ASTM A193 | General / high-temp |
| Low-temp bolting | A320 L7 / L7M / L43 | — | ASTM A320 | Low temperature |
| Austenitic stainless | A193 B8 / B8M Cl.1 & Cl.2 (304/316) | — | ASTM A193 | Corrosion |
| Carbon bolting | A307 Gr.A / Gr.B | — | ASTM A307 | General fixing |
| Nuts | A194 2H / 2HM / 4 / 7 / 7M / 8 / 8M | — | ASTM A194 | Matched to bolt |
| Stainless fasteners | F593 / F594 Group 1, 2, 3 (by alloy & condition) | — | ASTM F593 / F594 | Corrosion |
| Nickel alloys | B564 / B637 — N04400 (400), N06625 (625), N07718 (718) | — | ASTM B564 / B637 | Severe corrosion / high strength |
Chemical composition (representative)
| Grade | C | Mn | Cr | Ni | Mo | Other |
|---|---|---|---|---|---|---|
| A193 B7 | 0.37–0.49 | 0.65–1.10 | 0.75–1.20 | — | 0.15–0.25 | — |
| A193 B16 | 0.36–0.47 | 0.45–0.70 | 0.80–1.15 | — | 0.50–0.65 | V 0.25–0.35 |
| A320 L7 | 0.37–0.49 | 0.65–1.10 | 0.75–1.20 | — | 0.15–0.25 | — |
| A193 B8 (304) | 0.08 max | 2.00 max | 18.0–20.0 | 8.0–11.0 | — | — |
| A193 B8M (316) | 0.08 max | 2.00 max | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
Standards & specifications
Dimensional & thread
- ASME B18.2.1 / B18.2.2 hex bolts & nuts
- ASME B1.1 UN / 8-UN threads; ISO 261 metric
- ASME B18.22.1 washers
- ISO 4014 / 4017 / 4032 metric (legacy DIN 931/934 by contracted edition)
Product & service
- ASTM A193 / A194 / A320 pressure-temperature bolting & nuts
- ISO 898-1/-2 metric carbon/alloy · ISO 3506-1/-2 metric stainless
- ASTM A307 / A563, F593 / F594, F1554 anchors, F436 structural washers
- NACE MR0175 / ISO 15156 sour service by grade & condition
Mechanical properties (representative grades)
Representative grades — full MTC values on request. Values are ASTM/ASME specification minima or ranges at room temperature and vary with the diameter band and condition; verify the grade, class, diameter and edition per order.
| Grade / class | Type | Tensile min (MPa) | Yield min (MPa) | Elong min (%) | Hardness |
|---|---|---|---|---|---|
| A193 B7 (≤2½") | Alloy stud/bolt | 860 | 720 | 16 | ≤ 35 HRC |
| A193 B7 (2⅝–4") | Alloy stud/bolt | 795 | 655 | 16 | ≤ 35 HRC |
| A193 B7M | Alloy (sour) | 690 | 550 | 18 | ≤ 235 HBW |
| A193 B16 (≤2½") | Alloy high-temp | 860 | 725 | 18 | ≤ 35 HRC |
| A320 L7 (≤2½") | Low-temp alloy | 860 | 720 | 16 | ≤ 35 HRC |
| A320 L7M | Low-temp (sour) | 690 | 550 | 18 | ≤ 235 HBW |
| A320 L43 | Low-temp alloy | 860 | 720 | 16 | ≤ 35 HRC |
| A193 B8 Cl.1 (304 ST) | Austenitic SS | 515 | 205 | 30 | ≤ 223 HBW |
| A193 B8 Cl.2 (304 SH, ≤¾") | Austenitic SS | 860 | 690 | 12 | — |
| A193 B8M Cl.1 (316 ST) | Austenitic SS | 515 | 205 | 30 | ≤ 223 HBW |
| A193 B8M Cl.2 (316 SH, ≤¾") | Austenitic SS | 655 | 450 | 15 | — |
| A307 Gr.A / B | Carbon | 414 / 414–690 | — | — | — |
| A194 2H (nut) | Carbon/alloy nut | — | — | — | 24–38 HRC |
| A194 2HM (nut) | Alloy nut (sour) | — | — | — | ≥ 159 HBW, ≤ 235 HBW |
| A194 7 / 7M (nut) | Alloy nut | — | — | — | ≥ 159 HBW |
| A194 8 / 8M (nut) | Austenitic nut | — | — | — | ≤ 223 HBW |
Testing, inspection & documentation
| Test / document | Detail |
|---|---|
| Chemical / PMI | Composition to the ASTM spec; PMI on alloy / stainless grades (PMI does not establish every element or the final heat treatment) |
| Tensile / proof load | Tensile, yield or proof load and elongation per grade; nut grades by proof load to A194 |
| Hardness | Rockwell/Brinell; NACE MR0175 hardness for sour service (B7M/L7M ≤ 235 HBW) |
| Impact (Charpy) | A320 L7 / L43 at the grade’s specified impact-test temperature (a test temperature, not a minimum service temperature) |
| Dimensional / marking | Thread gauging, head / nut / washer dimensions, grade marking & lot traceability |
| Coating | Coating system, thickness & adhesion; thread allowance; friction factor where torque-controlled |
| Certification | EN 10204 3.1 as standard; 3.2 where the contracted inspection responsibilities are met |
Applications & industries served
Available forms, sizes & range
Standard forms and the family supply envelope. Exact diameter, pitch, length, grade / class and finish are confirmed per order; the ranges below are not a per-product capacity.
| Parameter | Range |
|---|---|
| Types | Stud bolts · hex bolts · nuts · washers · threaded rod · anchor & U-bolts |
| Size range | M6 – M64 / 1/4" – 4" (family envelope) |
Frequently asked questions
Which bolt and nut grades pair together?
ASTM A193 B7 studs commonly pair with A194 2H nuts; A320 low-temperature bolting with the matching A194 low-temperature nut; and B8 / B8M stainless with A194 8 / 8M nuts. We supply matched, correctly hardened assemblies, and the exact pairing is confirmed for the temperature, service and any sour requirement rather than assumed.
Do you supply coated fasteners?
Yes — PTFE / xylan, hot-dip galvanised and zinc coatings to the project specification, with the coating system, thickness and thread allowance stated, and the friction factor where torque control matters. A salt-spray figure is an identification test, not a guaranteed field life.
Are low-temperature and sour-service grades available?
Yes — A320 L7 / L43 for low temperature, impact-tested at the grade's specified test temperature, and NACE MR0175 / ISO 15156 hardness-controlled bolting where sour service requires it. Sour suitability depends on the material condition, stress and environment, not hardness alone.
What is the difference between a stainless grade and a property class?
A 304 or 316 material certificate identifies the alloy, not the finished-fastener strength. Stainless bolts and studs are supplied to a property class — for example ISO 3506-1 A2 or A4 with a strength class, or ASME A193 B8 / B8M Class 1 or Class 2 — which is confirmed per order.
Do you supply metric as well as inch fasteners?
Yes. Inch fasteners follow ASME B1.1 threads and the ASME B18 dimensional standards; metric fasteners follow ISO threads with ISO 898-1 / -2 (carbon and alloy) or ISO 3506-1 / -2 (stainless). Legacy DIN drawings are checked against the contracted edition, as dimensions can differ.
What documentation and testing is provided?
EN 10204 3.1 as standard and 3.2 where the contracted third-party inspection responsibilities are met, with tensile or proof-load, hardness and (for low-temperature grades) impact tests, plus coating and PMI checks as specified. PMI does not establish every element or the final heat treatment.
Request a quote
Send your requirement to Sagiant Piping Industries and our team responds with grade, material selection, availability and pricing for fasteners. Attach a BOQ, line list or drawing for a faster, more accurate quotation.
- Fast RFQ response with grade & material-selection support
- EN 10204 3.1 / 3.2 certification, PMI & third-party inspection
- BOQ & line-list project supply — India & export
Mechanical & chemical values shown are ASTM/ASME specification figures; certified heat-specific values appear on the MTC. Availability is confirmed with the quotation.
