Email:
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Phone:
+91 93135 43530
Address:
133/1 Ground, Mansuri Block, Opp. Dudheshwar Water Tank, Ahmedabad-380004, Gujarat, India
A193 B7 Stud Bolt with A194 2H Heavy Hex Nut supplier in Ahmedabad, Gujarat. ASTM A193 Grade B7 (Cr-Mo alloy steel, 125 ksi tensile, -45°C to +450°C) stud bolt — ASTM A194 Grade 2H heavy hex nut (175 ksi proof…
Stud Bolt — ASTM A193 B7 — 2H Nut
Price on Request
About Company
- KRISHNA INDUSTRIES
- GST No. : 24AKLPP6499B1ZT
- Ahmedabad, Gujarat, India
- Manufacturer, Traders & Wholesale Supplier
- Year of Establishment : Since 1985
- Annual Turnover : Below Rs. 25 Crore Approx.
- Banker : APANI SAHAKARI BANK LIMITED
- Company CEO : Ruchin Panchal
- Constitution of Business : Proprietorship
- Leading Valve Supplier in India covering Maharashtra, Gujarat, Tamil Nadu, Karnataka, Telangana, Delhi NCR, West Bengal, Rajasthan, Madhya Pradesh, Uttar Pradesh, Punjab, Haryana, Andhra Pradesh, Odisha, Chhattisgarh, Jharkhand, Bihar, Kerala, Assam.
- Major Industrial Supply Cities: Ahmedabad, Vadodara, Rajkot, Surat, Mumbai, Pune, Thane, Nashik, Nagpur, Chennai, Coimbatore, Bengaluru, Hyderabad, Delhi, Noida, Gurugram, Faridabad, Kolkata, Jaipur, Indore, Bhopal, Lucknow, Kanpur, Ludhiana, Visakhapatnam.
Description
A193 B7 Stud Bolt with A194 2H Heavy Hex Nut Supplier India | ASME B18.2 | Plain / HDG / Zinc | All Sizes | Flanged Joint Bolting Class 150–2500 | KELOR
Supplier: Krishna Industries (KELOR) – Ahmedabad, Gujarat, India
Established: 2017 | GSTIN: 24AKLPP6499B1ZT | IEC: AKLPP6499B
MOQ: 100 Nos | Stud: ASTM A193 Grade B7 | Nut: ASTM A194 Grade 2H
Standard: ASME B18.2 | Thread: UNC ASME B1.1 | Finish: Plain / HDG / Zinc
A193 B7 Stud Bolt Supplier in India
Krishna Industries (KELOR), based in Ahmedabad, Gujarat, supplies A193 B7 Stud Bolts with A194 2H Heavy Hex Nuts — ASTM A193 Grade B7 Cr-Mo alloy steel stud — ASTM A194 Grade 2H heavy hex nut — ASME B18.2 dimensions — UNC thread (ASME B1.1) — plain (black) / yellow zinc plated / hot dip galvanised (HDG ASTM A153) — all standard sizes — supplied as matched B7/2H set — GST invoice — MOQ 100 Nos — Pan India dispatch from Ahmedabad.
A193 B7 with A194 2H is the most widely specified stud bolt grade for Indian process plant flanged joints — from Class 150 utility piping to Class 2500 high pressure oil and gas. Furthermore, this pairing is not just conventional practice — it is a requirement of ASME PCC-1 and ASME B31.3, which mandate that nut proof load must exceed bolt yield strength to ensure the bolt is always the weaker element in the joint. Consequently, substituting a non-2H nut on a B7 stud creates a code non-conformance and a leakage risk.
Why B7 Must Be Paired with 2H — The Code Requirement
The A193 B7 / A194 2H pairing is not arbitrary. ASME PCC-1 (Guidelines for Pressure Boundary Bolted Flange Joint Assembly) requires that the nut proof load exceed the bolt minimum yield strength. This ensures the bolt yields before the nut strips — maintaining preload integrity in the flanged joint throughout the bolting cycle.
| Bolting Combination | Nut Proof Load | B7 Stud Yield | Code Compliant? | Risk |
|---|---|---|---|---|
| A193 B7 + A194 2H ✅ | 175 ksi | 105 ksi (≤2½”) | ✅ Yes — 2H exceeds B7 yield by 67% | None — bolt yields before nut strips — correct behaviour |
| A193 B7 + IS 1367 Grade 8 | ~116 ksi | 105 ksi | ❌ Marginal — Grade 8 nut barely exceeds B7 yield — not ASME compliant | Nut galling under high preload torque — joint may not achieve required bolt load — leakage at operating pressure |
| A193 B7 + IS 1367 Grade 5 | ~85 ksi | 105 ksi | ❌ No — Grade 5 nut weaker than B7 bolt | Nut strips before adequate bolt preload — joint leaks immediately under operating pressure — common cause of Indian site flanged joint leakage |
| A193 B8M + A194 2H | 175 ksi | B8M yield ~30 ksi | ❌ Incorrect pairing — galvanic corrosion between CS nut and SS stud in wet service | Galvanic attack on SS stud at nut contact — SS stud corrosion — seizure — specify A194 8M nut with B8M stud |
Stud Bolt vs Hex Bolt — Which to Specify for ASME B16.5 Flanged Joints
| Feature | Stud Bolt (Correct for ASME B16.5) | Hex Bolt (Not standard for ASME B16.5) |
|---|---|---|
| Construction | Full-threaded rod — nut on both ends — no head | Head on one end — nut on other end |
| Load Distribution | ✅ Both flanges engaged via nuts — uniform preload on both flange faces — consistent gasket compression | Head bears on one flange face — less uniform — head can damage raised face gasket seating area |
| Tensioning | ✅ Both nuts accessible for hydraulic tensioner or torque wrench — standard for ASME PCC-1 controlled bolting | One side is head — hydraulic tensioner applies to nut side only — less precise preload control |
| ASME B16.5 Compliance | ✅ ASME B16.5 Table E1.1 specifies stud bolts for all pressure class flanged joints — standard for Indian process plant valve and pipe flanging | Not specified in ASME B16.5 for pressure boundary flanged joints — acceptable for structural, equipment mounting, non-pressure service only |
| Specify When | ✅ Always — for all ASME B16.5 Class 150–2500 flanged valve, flange, heat exchanger, and pressure vessel joints | Structural steel, equipment base plate, non-pressure service — never for process plant flanged pipe and valve joints |
Technical Specifications
| Parameter | A193 B7 Stud Bolt | A194 2H Heavy Hex Nut |
|---|---|---|
| ASTM Grade | ASTM A193 Grade B7 | ASTM A194 Grade 2H |
| Material | Chromium-Molybdenum alloy steel (4140/4142 Cr-Mo) — quenched and tempered | Medium carbon steel — quenched and tempered |
| Tensile Strength | 125 ksi (860 MPa) for dia ≤2½” | — |
| Yield Strength | 105 ksi (720 MPa) for dia ≤2½” | — |
| Proof Load | — | 175 ksi (1207 MPa) |
| Hardness | 35 HRC max | C24–C34 Rockwell |
| Temperature Range | -45°C to +450°C | Matched to B7 stud service range |
| Thread | UNC — ASME B1.1 (coarse thread standard) | UNC — ASME B1.1 |
| Dimensions | ASME B18.2.1 | ASME B18.2.2 — Heavy Hex |
| Size Range | M12 to M48 / ⅜” to 2″ standard | Matching heavy hex to stud size |
| Finish Options | Plain (black oxide) / Yellow zinc plated / Hot dip galvanised HDG ASTM A153 | Matching finish to stud |
| Certification | Mill test certificate — chemical composition + mechanical properties | Mill test certificate |
| MOQ | 100 Nos per size | Supplied with stud as matched set |
| HSN Code | 73181590 | 73182900 |
Coating Selection Guide
| Finish | Specify For | Not For |
|---|---|---|
| Plain (Black Oxide) | ✅ Indoor process plant — dry or oil-coated storage — standard for Indian refinery, chemical plant, and power plant indoor bolting — lowest cost | Outdoor, coastal, or wet service — plain B7 corrodes rapidly when exposed to rain and salt air |
| Yellow Zinc Plated | ✅ Mild corrosion protection — indoor plant with occasional moisture — storage before installation — general industrial warehouse stock | Coastal and offshore — zinc plating insufficient for continuous salt spray exposure |
| Hot Dip Galvanised (HDG) ASTM A153 | ✅ Outdoor pipe racks — coastal industrial — water treatment plants — outdoor valves and flanges — 45–85 micron zinc coating provides 10–25 year corrosion protection in industrial outdoor environments | High temperature above 250°C — zinc coating embrittlement risk at elevated temperature — specify plain B7 for high temp service |
Applications in Indian Industries
Flanged Valve and Pipe Joint Bolting — Process Plant
A193 B7 / A194 2H plain or zinc plated — all standard ASME B16.5 flange sizes Class 150 to 2500. The default bolting specification on every Indian process plant piping class document for carbon steel service — chemical plants, refineries, power plants, CGD networks. Furthermore, stud length is specified per ASME B16.5 Table — two thread pitches protruding beyond nut at each end is the standard assembly requirement per ASME PCC-1.
Pressure Vessel and Heat Exchanger Bolting
A193 B7 / A194 2H for ASME VIII Div 1 pressure vessel flange bolting — shell and channel flanges, manhole cover bolting, nozzle flange bolting. MTC (mill test certificate) mandatory for all pressure vessel bolting per ASME VIII Div 1 UG-10. Moreover, 3.1 MTC (manufacturer’s test certificate) is the standard — 3.2 MTC (third party witnessed) available on request for critical pressure boundary bolting.
Outdoor Pipe Rack and Water Treatment — HDG Finish
A193 B7 / A194 2H hot dip galvanised (HDG ASTM A153) — outdoor pipe racks, cooling water flanges, water treatment plant flanged joints, coastal industrial flanged piping. HDG coating provides significantly longer service life than yellow zinc plating in outdoor Indian conditions — coastal Gujarat, Maharashtra, and Tamil Nadu industrial installations. Additionally, HDG prevents the bolt seizure in nuts that is common with plain corroded B7 bolting on outdoor flanges at maintenance time.
Related Products — Krishna Industries (KELOR)
- Stud Bolt — Multiple Grades — A193 B7, B8 (SS304), B8M (SS316), A320 L7 (low temp) — full stud bolt range
- Hex Bolt — for structural and non-pressure service where hex bolt is the correct specification
- Double Ended Stud — for equipment and machinery mounting — different from full-thread flange stud bolt
- SS Weld Neck Flange — ASTM A182 F316 flanges — specify A193 B8M / A194 8M SS stud bolts for SS flanged joints — not B7/2H
- Y Strainer — flanged SS Y strainer — also requires SS bolting (B8M/8M) not carbon steel B7/2H for SS-to-SS flanged joints
Frequently Asked Questions
1. Why must A193 B7 be used with A194 2H nut and not a standard IS Grade 8 or Grade 5 nut?
ASME PCC-1 requires that nut proof load exceed bolt yield strength so that the bolt yields before the nut strips — this ensures predictable joint behaviour and maintains gasket preload. A194 2H has a 175 ksi proof load against B7’s 105 ksi yield — a 67% margin. An IS Grade 8 nut has approximately 116 ksi proof load — marginal. An IS Grade 5 nut has approximately 85 ksi — lower than B7 yield — the nut will strip before the bolt reaches yield, making adequate preload impossible. Joints with wrong nuts always leak at operating pressure or at the first thermal cycle. This is the most common cause of flanged joint leakage on Indian process plant sites.
2. What stud bolt length should I specify for a given flange?
Stud bolt length for ASME B16.5 flanges is specified per ASME B16.5 Table — the table lists stud bolt length and quantity for each pipe size and pressure class combination. The general rule is: stud length = flange face-to-face thickness (both flanges) + gasket thickness + 2 x nut height + 2 x two thread pitches protruding beyond nut. For standard raised face flanges with a 3mm spiral wound gasket, ASME B16.5 Table values give the correct stud length directly. WhatsApp flange size, pressure class, and gasket type for stud length confirmation.
3. When should I specify HDG instead of plain finish?
Specify HDG (hot dip galvanised ASTM A153) for any bolting that will be installed outdoors, in a coastal environment, in a water treatment plant, or in any location where the bolting will be exposed to rain, humidity, or salt air during service. Plain black oxide B7 corrodes rapidly outdoors and the nuts seize on the corroded studs within 2–3 years, making removal for maintenance extremely difficult. HDG provides 10–25 years corrosion protection depending on environment. The HDG premium over plain is small relative to the cost of cutting seized bolts and refacing flange faces during maintenance.
4. Can I use B7/2H bolting on stainless steel flanges?
No — carbon steel B7 stud bolt in contact with stainless steel flange in wet or outdoor service creates a galvanic couple — carbon steel corrodes preferentially and the stud corrodes and seizes in the SS flange. For SS-to-SS flanged joints (SS304 or SS316 flanges), specify A193 B8 (SS304 stud) with A194 Grade 8 nut, or A193 B8M (SS316 stud) with A194 Grade 8M nut. B7/2H is correct only for carbon steel flange to carbon steel flange joints.
5. What is the MOQ and what documents are provided?
MOQ is 100 Nos per size per finish. Every order includes mill test certificate (MTC) confirming ASTM A193 B7 chemical composition and mechanical properties, and ASTM A194 2H nut certificate — with heat number traceability for pressure vessel and EPC project documentation requirements. GST invoice with GSTIN 24AKLPP6499B1ZT. WhatsApp thread size, finish (plain / zinc / HDG), length, and quantity for pricing within 2 hours.
Our Other Products:
https://kelorvalves.com/hex-bolt-m12-12mm-x-35mm-x-1-75mm-mild-steel-ms-zinc-plated/
https://kelorvalves.com/m4-hex-nut-ss304-diameter-4mm/
Hex Bolt | B7 B8M SS304 SS316 Grade 8.8 | Metric Inch | Supplier India
Double Ended Stud | B7 B8 SS304 SS316 | Metric Inch | Supplier India
Conclusion
Krishna Industries (KELOR) supplies A193 B7 Stud Bolts with A194 2H Heavy Hex Nuts — ASTM A193 Grade B7 Cr-Mo alloy steel stud — ASTM A194 Grade 2H heavy hex nut — ASME B18.2 dimensions — UNC thread — plain / yellow zinc / hot dip galvanised (HDG ASTM A153) — all standard sizes — mill test certificate — GST invoice — MOQ 100 Nos — Pan India dispatch from Ahmedabad. WhatsApp thread size, finish, length, and quantity for pricing within 2 hours.
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