ASME Fasteners
Manufacturer
India · Mumbai
ASME Fastener Standards — Complete Code Reference
ASME publishes the standards that govern pressure flange bolting, pressure vessel fasteners, piping system fasteners, and fastener dimensions for North American and international process plant design. Akbar Fasteners manufactures to all major ASME bolting codes.
ASME B16.5
The cornerstone ASME fastener standard — specifies stud bolt lengths, thread type, and number of studs per flange for ASME B16.5 flange classes 150, 300, 600, 900, 1500, and 2500 in pipe sizes NPS ½” through 24″. ASME B16.5 is not a material standard — it defines dimensions. Material is specified separately by ASTM A193 grade. For every ASME B16.5 flange bolt-up: B16.5 (length/quantity) + A193 (bolt material) + A194 (nut material) = complete specification.
ASME B16.47
Extension of B16.5 for large diameter flanges NPS 26″–60″. Series A (formerly MSS SP-44) used in pipelines and high-pressure applications; Series B (formerly API 605) for lower-pressure pipeline service. Stud bolt lengths and quantities for large-bore flanges in refinery, pipeline, and offshore service. Same ASTM A193/A194 material specification as B16.5 — only stud bolt lengths differ for the larger flange face dimensions.
ASME Section VIII
ASME Boiler and Pressure Vessel Code Section VIII governs pressure vessel design and includes fastener requirements for vessel nozzle flanges, manhole covers, and head closures. Division 1 covers standard design; Division 2 covers alternative design with higher stress allowables. Section VIII specifies allowable bolt stress values (Sb) per material and temperature, governing the required bolt cross-sectional area for each flange class. ASTM A193/A194 materials used throughout.
ASME B31.3
Process Piping Code — governs bolting for all flanged joints in chemical plant, refinery, and process industry piping systems including Category D (non-hazardous), Normal Fluid Service, Severe Cyclic, Category M (lethal), and High Pressure. B31.3 references ASME B16.5 for flange dimensions and ASTM A193/A194 for bolt materials. Specifies additional inspection and documentation requirements for high-risk fluid categories.
ASME B18.2.2
Square and Hex Nuts — the ASME dimensional standard for heavy hex nuts used in ASME B16.5 stud bolt assemblies. ASME B18.2.2 defines the wider across-flats (AF) and greater height of the heavy hex nut form vs DIN 934 standard hex, providing higher bearing area and greater thread engagement depth. The B18.2.2 heavy hex nut is the standard nut form for all ASME B16.5 flange stud bolt assemblies — not a standard DIN 934 hex nut.
ASME PCC-1
Guidelines for Pressure Boundary Bolted Flange Joint Assembly — the ASME standard governing how ASME B16.5 stud bolt assemblies are tightened. Covers lubrication factor (K), cross-bolt torque sequence, target bolt load, and documentation of the bolt-up procedure. In exotic alloy service (Hastelloy B3, Monel K500), ASME PCC-1 lubrication factor K is particularly important because nickel-alloy thread galling changes the torque-preload relationship compared to carbon steel B7 assemblies.
B16.5 Stud Bolt Lengths — Class 150 to Class 600 (Common Sizes)
ASME B16.5 stud bolt lengths for fully threaded studs in Class 150, 300, and 600 flanges — the three most common pressure classes in refinery and chemical plant service. Class 900, 1500, and 2500 lengths and large-bore sizes on request. All lengths in mm.
| NPS (inch) | Bolt Size | No. of Bolts | Class 150 Length (mm) | Class 300 Length (mm) | Class 600 Length (mm) |
|---|---|---|---|---|---|
| ASME B16.5 STUD BOLT LENGTHS — ASTM A193 B7 / B8M / EXOTIC ALLOY — FULLY THREADED | |||||
| ½” | M12 (½”-13UNC) | 4 | 75 | 95 | 105 |
| ¾” | M12 (½”-13UNC) | 4 | 80 | 100 | 115 |
| 1″ | M16 (⅝”-11UNC) | 4 | 90 | 115 | 130 |
| 1½” | M16 (⅝”-11UNC) | 4 | 100 | 125 | 145 |
| 2″ | M16 (⅝”-11UNC) | 8 | 110 | 140 | 160 |
| 3″ | M20 (¾”-10UNC) | 8 | 125 | 160 | 190 |
| 4″ | M20 (¾”-10UNC) | 8 | 140 | 175 | 210 |
| 6″ | M24 (⅞”-9UNC) | 12 | 155 | 200 | 240 |
| 8″ | M24 (⅞”-9UNC) | 12 | 175 | 220 | 270 |
| 10″ | M30 (1″-8UNC) | 16 | 195 | 250 | 300 |
| 12″ | M30 (1″-8UNC) | 16 | 215 | 270 | 330 |
| 14″ | M36 (1⅛”-8UNC) | 20 | 240 | 305 | 370 |
| 16″ | M36 (1⅛”-8UNC) | 20 | 255 | 325 | 395 |
Class 900 · 1500 · 2500 · NPS 18″–24″ lengths · B16.47 large bore all on request: sales@akbarfasteners.in
ASME Fastener Types — All Forms Available
All ASME fastener forms from ASTM-certified bar stock. NABL-accredited mechanical testing on every lot. ASME B16.5 dimensional compliance on every stud bolt set. Full traceability from bar stock heat number to dispatched assembly.
ASME Stud Bolts
Fully threaded stud bolts per ASME B16.5 lengths — A193 B7 (alloy steel), B8M (316L SS), B8T (321 SS), B8C (347 SS), B16 (Cr-Mo-V), and all exotic alloy grades. ASME B16.5 Class 150–2500, NPS ½”–24″, metric equivalent M12–M100, lengths per B16.5 table. Fully threaded, equal-end stud configuration. NABL tensile and hardness on every lot.
ASME Heavy Hex Nuts
ASTM A194 Grade 2H (B7 standard), 2HM (NACE sour service ≤235 HB), 8M (316L), 8T (321), 8C (347) heavy hex nuts to ASME B18.2.2 dimensions — wider across-flats than DIN 934, required for ASME B16.5 stud bolt assembly documentation. Matched from same ASTM-certified heat as stud bolts. Single MTC for complete assembly. NABL hardness confirming NACE limit for 2HM lots.
NACE Sour Service Sets
A193 B7M + A194 2HM matched stud bolt assembly sets for NACE MR0175/ISO 15156 sour service. Hardness certificate per ASTM A370 confirming B7M ≤235 HB (≤22 HRC) and 2HM nuts ≤235 HB. Complete NACE documentation package including MTC, NABL hardness cert, COC for offshore, subsea, and sour gas process flanges.
ASME Stud Bolt Sets
Complete ASME B16.5 stud bolt sets — stud bolts + A194 heavy hex nuts + washers from same certified heat, pre-packed per flange (NPS, Class, material) with single MTC, NABL report, and COC. Pre-packed sets eliminate assembly documentation errors, simplify TPI hold plans, and speed up flange bolt-up on site. Hastelloy, Monel, Inconel, SS, and carbon steel sets available.
ASME VIII Vessel Bolting
Stud bolts and hex bolts for ASME Section VIII pressure vessels — nozzle flange studs (A193 B7/B8M), manhole cover stud bolts, head closure studs, and all internal vessel bolting per ASME VIII design specification. ASME SB-materials (SB-574, SB-865, SB-446) for exotic alloy vessel bolting. Full ASME VIII-compliant documentation including SB-material MTC and NABL mechanical test reports.
ASME B31.3 Piping Bolts
All ASME B31.3 process piping service categories — Normal Fluid Service (NFS), Category D (non-hazardous), Severe Cyclic, Category M (lethal fluid), and High Pressure (HP). B31.3 Category M and HP require additional inspection documentation beyond NFS. A193 B7, B8M, and exotic alloy stud bolt sets with B31.3-specified inspection documentation for each service category.
ASME Threaded Rods
A193 B7, B8M threaded rods for ASME pressure vessel and process equipment structural applications. Full thread, metric and inch UNC. Lengths to 3,000mm. For all ASME applications where continuous threaded rod in ASTM A193 material is required — process vessel support rods, heat exchanger internal tie-rods, and structural ASME process equipment connections.
Custom ASME Fasteners
Non-standard ASME configurations — unequal-end stud bolts, Class 2500 exotic alloy large bore sets, ASME VIII special bolt designs, and any ASME code configuration requiring non-standard dimensions in exotic alloy. Contact sales@akbarfasteners.in with ASME code reference, flange NPS, Class, material, and documentation requirement.
ASME B16.5 Exotic Alloy Stud Bolt Sets
Every exotic alloy stud bolt set certified to the material’s ASME SB-equivalent standard with ASME B16.5 dimensional compliance. Single MTC for stud bolt + nut assembly from same certified heat.
Hastelloy C276
Hastelloy B3
Monel K500
Inconel 625
Incoloy 825
Monel 400
SS 321 — A193 B8T
SS 316L — A193 B8M
ASME Fasteners Application Areas
Wherever an ASME code governs the design — refinery pressure flanges, offshore process vessels, chemical plant piping, LNG cryogenic systems, and power generation pressure equipment.
Refinery & Petrochemical
B8M SS flange assemblies
Oil & Gas
offshore B16.5 flanges
Offshore & FPSO
Class 1500/2500 high-P
Power Generation
ASME VIII boiler bolts
Chemical Processing
ASME B31.3 Category M
LNG / Cryogenic
ASME B16.5 cryo flanges
Pharmaceutical
316L B31.3 piping bolts
Nuclear
B8C A193 nuclear sets
ASME Fastener Standards Coverage
Same ISO 9001:2015 quality system across all ASME grades. NABL-accredited mechanical testing on every lot. Full MTC traceability from bar stock heat to dispatched assembly.
Complete ASME Documentation Package
ASTM / SB-Grade Stated
Tensile · Hardness
NACE 2HM ≤235 HB
Conformance
TÜV · BV · Lloyds
Need ASME
Certified Fasteners?
ASME code · B16.5 Class · NPS · material grade · NACE requirement · documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours with pricing and full documentation list.
Export: +91 8696 32 4646 · Support: +91 800 9315 333 · export@akbarfasteners.in