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Certifications: EN 10204 3.1 / 3.2 material test certificates, ISO 3506 property class compliance, PMI/hardness verification, and complete export documentation packages.
Stainless Steel
Threaded Rods
A world-class technical reference for EPC contractors, structural and piping engineers, procurement heads, and TPI inspection agencies specifying stainless steel threaded rod (studding / all-thread) — covering alloy and property class selection, thread standards, tensile and proof load performance, corrosion resistance by grade, manufacturing route, and the inspection and documentation discipline required for critical structural, piping-support, and process-equipment fastening applications.
Grade Classification
& Load Behaviour
Stainless steel threaded rod is specified over carbon steel wherever corrosion resistance, non-magnetic behaviour, hygienic surface requirements, or long-term maintenance-free fastening performance in exposed, washdown, chemical, or marine environments outweighs the higher material cost of stainless over zinc-plated or hot-dip galvanised carbon steel alternatives.
1.1 — Engineering Context and Application Rationale
Threaded rod (also termed studding, all-thread rod, or continuously threaded bar) is a fully threaded round bar cut to length and used as a fastener where a through-bolt, hanger rod, anchor rod, or tie rod requires threading along its full or partial length rather than a discrete head-and-shank bolt geometry. In stainless steel, threaded rod is the standard fastening solution for pipe support hanger systems, HVAC ductwork suspension, cable tray and busway support, structural steel tie rods in corrosive or washdown environments, pressure vessel and heat exchanger flange studding (in conjunction with A193/A320 equivalents for pressure service), architectural facade fixings, and any application where a continuous thread length is needed to accommodate variable grip length, field adjustment, or a double-nut tensioning arrangement.
The decisive engineering advantage of stainless steel threaded rod over galvanised or plated carbon steel is the corrosion resistance provided by the passive chromium oxide film inherent to stainless steel — a self-healing surface layer that does not degrade or sacrifice itself the way a zinc or cadmium coating does. Galvanised carbon steel threaded rod provides a finite corrosion protection life determined by coating thickness (typically 20–30 years in mild atmospheric exposure, far less in coastal, chemical, or high-humidity washdown environments) — once the zinc layer is consumed or mechanically damaged (thread engagement, cutting, field modification), the underlying carbon steel corrodes at the unprotected exposure point. Stainless steel threaded rod provides indefinite corrosion resistance in the environments for which the grade is suited, including at cut ends, drilled holes, and thread engagement points, because the passive film re-forms on any freshly exposed stainless surface in the presence of oxygen.
1.2 — Grade Classification: A2 vs. A4 Stainless
Grade A2 (AISI 304 / 304L Equivalent)
Austenitic Cr-Ni stainless (approx. 18% Cr, 8% Ni) — the general-purpose stainless threaded rod grade per ISO 3506-1 / DIN 267-11. Good corrosion resistance in atmospheric, mild washdown, food-processing, and freshwater environments; not resistant to chloride-bearing environments (coastal/marine atmospheres, swimming pool chemical exposure, de-icing salt splash zones) where pitting and crevice corrosion initiate at threaded engagement points and crevices. The default stainless threaded rod grade for indoor structural, HVAC, and general industrial fastening applications where chloride exposure is absent or minimal.
Grade A4 (AISI 316 / 316L / 316Ti Equivalent)
Austenitic Cr-Ni-Mo stainless (approx. 17% Cr, 11% Ni, 2–2.5% Mo) — the molybdenum addition significantly improves resistance to pitting and crevice corrosion in chloride-bearing environments compared to A2/304. Specified for marine, coastal, offshore, chemical processing, swimming pool, and de-icing salt exposure applications where A2/304 would suffer localized corrosion at crevices and thread roots. A4-80 (property class 80, cold-worked) is the standard high-strength A4 threaded rod grade for structural and marine fastening; A4-70 for general-purpose A4 applications where full A4-80 strength is not required.
316Ti — Titanium-Stabilised Variant
316 stainless with titanium addition (typically 5× carbon content minimum) to stabilise carbon as titanium carbide rather than chromium carbide — prevents sensitization (chromium carbide precipitation at grain boundaries) during welding or prolonged exposure in the 425–870°C sensitization temperature range. Specified for threaded rod used in welded assemblies or elevated-temperature process equipment where post-weld intergranular corrosion resistance is a specific project requirement; not typically required for room-temperature mechanical fastening applications where no welding heat input occurs at the threaded rod itself.
Duplex Grades (1.4462 / 2205) — Specialist High-Strength Option
Duplex stainless threaded rod (UNS S31803/S32205, EN 1.4462) offers approximately double the yield strength of standard austenitic A4 stainless combined with superior chloride pitting/crevice/stress-corrosion-cracking resistance — specified for offshore, subsea-adjacent, and highly aggressive chemical process fastening applications where standard A4 threaded rod is at risk of chloride stress corrosion cracking under sustained tensile load (a known A4/316 failure mode in hot chloride environments above approximately 60°C). Duplex threaded rod is a specialist, higher-cost item procured against specific project engineering specification rather than general stock.
1.3 — Property Class System (ISO 3506-1)
Stainless steel fastener mechanical properties are classified by ISO 3506-1 property class, expressed as a two-digit or three-digit number (50, 70, 80) representing approximately 1/10th of the minimum tensile strength in MPa for the given condition — analogous to, but numerically distinct from, the property class system (4.6, 8.8, 10.9) used for carbon and alloy steel fasteners per ISO 898-1. Property class 50 represents the solution-annealed (soft) condition; property class 70 and 80 represent cold-worked (strain-hardened) conditions achieved by cold drawing the bar prior to thread rolling, which increases tensile and yield strength at some cost to ductility and, in certain aggressive chloride environments, at some increase in stress corrosion cracking susceptibility compared to the fully annealed condition.
| Property Class | Condition | Min. Tensile Strength (MPa) | Min. 0.2% Proof Stress (MPa) | Min. Elongation (%) | Typical Application |
|---|---|---|---|---|---|
| 50 | Solution annealed (soft) | 500 | 210 | 0.6d (d = bolt Ø) | Large diameter rod; maximum ductility; low-load fastening |
| 70 | Cold worked (moderate) | 700 | 450 | 0.4d | General structural and mechanical fastening — most common grade for M6–M20 |
| 80 | Cold worked (high) | 800 | 600 | 0.3d | High-load structural fastening; marine and offshore A4-80; smaller diameters only (typically ≤ M20/M24 due to cold-working limits on larger bar) |
1.4 — Tensile and Proof Load Performance
d₂ = Basic pitch diameter of the thread (mm)
P = Thread pitch (mm)
σ_proof = Minimum 0.2% proof stress for the property class (MPa) — see Table 1.A
F_proof = Proof load — the maximum axial load the threaded rod can sustain without permanent (plastic) deformation
Design note — working load vs. proof load:
The proof load is not the allowable working load. A safety factor (typically 2.5–4:1 depending on the application code — building structural anchor codes, pressure equipment codes, and lifting/rigging codes each specify different minimum factors) must be applied to the proof load or ultimate tensile load to determine the safe working load for a specific application and load case (static, dynamic, seismic).
Tensile stress area A_s (M16, coarse pitch 2.0 mm) ≈ 157 mm²
σ_proof (Class 70) = 450 MPa
F_proof = 157 × 450 = 70,650 N ≈ 70.6 kN
Applying a structural safety factor of 3:1 for a static hanger application: allowable working load ≈ 23.5 kN — always confirm the applicable safety factor from the governing design code for the specific application before finalising the working load.
Submit your diameter, thread form, grade, property class, length, and quantity for a documented RFQ within 24 hours.
Dimensions &
Standards Compliance
Stainless steel threaded rod dimensions, thread forms, and mechanical property requirements are governed by ISO 3506-1, DIN 976-1, ASTM F593/F594, and the applicable thread-form standard (ISO 68-1 metric, ASME B1.1 unified). All applicable standards are supported at RR Hydraulic.
Submit diameter, thread form, grade, length, and quantity to sales@rrhydraulics.com for a certified offer.
2.1 — Thread Form Compatibility
| Thread Form | Standard | Typical Region | Nut Compatibility | Notes |
|---|---|---|---|---|
| Metric Coarse | ISO 68-1 / ISO 261 | Global / EU / Asia | ISO 4032 / DIN 934 hex nuts | Default global thread form; specify by M-designation (M8, M12, M16 etc.) |
| Metric Fine | ISO 68-1 / ISO 262 | Precision / vibration-resistant applications | Matching fine-pitch nuts | Finer pitch increases thread engagement and vibration resistance; lower per-thread shear area |
| UNC (Unified Coarse) | ASME B1.1 | North America | ASME B18.2.2 hex nuts | US project specifications; not interchangeable with metric — verify thread callout explicitly |
| UNF (Unified Fine) | ASME B1.1 | North America — precision / high-strength | Matching UNF nuts | Used where higher tensile stress area per diameter or finer adjustment is required |
| BSW / BSF (Whitworth) | BS 84 | Legacy UK / Commonwealth | Whitworth-form nuts | Legacy/replacement projects only — rarely specified on new-build EPC work |
2.2 — Dimensional Reference: Diameter, Pitch, and Tensile Stress Area
| Size | Pitch (mm) | Pitch Ø d₂ (mm) | Tensile Stress Area (mm²) | Proof Load Class 70 (kN) | Weight A4 (kg/m) |
|---|---|---|---|---|---|
| M8 | 1.25 | 7.19 | 36.6 | 16.5 | 0.40 |
| M10 | 1.5 | 9.03 | 58.0 | 26.1 | 0.62 |
| M12 | 1.75 | 10.86 | 84.3 | 37.9 | 0.89 |
| M16 | 2.0 | 14.70 | 157.0 | 70.6 | 1.58 |
| M20 | 2.5 | 18.38 | 245.0 | 110.3 | 2.47 |
| M24 | 3.0 | 22.05 | 353.0 | 158.9 | 3.55 |
| M30 | 3.5 | 27.73 | 561.0 | 252.5 | 5.66 |
| M36 | 4.0 | 33.40 | 817.0 | 367.7 | 8.24 |
2.3 — Applicable Standards and Compliance Framework
ISO 3506-1
Mechanical Properties of Corrosion-Resistant Stainless Steel Fasteners — Part 1: Bolts, Screws and Studs. The primary international standard governing stainless steel threaded rod mechanical properties, property class designation (A2-70, A4-80 etc.), and testing methodology. Specifies minimum tensile strength, proof stress, elongation, and hardness for each grade/property-class combination, and the required chemical composition ranges for A1 through A5 stainless steel grades.
DIN 976-1
Studs (Threaded Rods) — Part 1: Coarse Thread and Fine Pitch Thread — the dimensional standard most commonly cited for European and internationally-supplied threaded rod, defining standard mill lengths (1 m, 2 m, 3 m), diameter range, thread tolerance class, and permissible straightness deviation. DIN 976-1 threaded rod is manufactured in property classes and materials including A2/A4 stainless per the referenced ISO 3506-1 mechanical requirements.
ASTM F593 / F594
ASTM F593 (Stainless Steel Bolts, Hex Cap Screws, and Studs) and F594 (Stainless Steel Nuts) are the primary US standards for stainless fastener mechanical properties, referenced for threaded rod supplied to North American project specifications where ASTM (rather than ISO/DIN) governs the procurement documentation. Alloy Group 1 (304/304L equivalent to A2) and Group 2 (316/316L equivalent to A4) with Condition CW (cold-worked) or A (annealed) designations parallel the ISO 3506-1 property class system.
ASME B1.1 / B1.13M
ASME B1.1 (Unified Inch Screw Threads — UN/UNR Form) governs UNC/UNF thread form geometry for North American projects; ASME B1.13M is the metric thread equivalent for projects requiring metric thread geometry to a US-referenced dimensional standard. Both standards define the thread profile, tolerance class (2A/3A external), and pitch diameter limits that determine nut engagement and fit.
EN 10088 / ASTM A276
EN 10088 (Stainless Steels) and ASTM A276 (Stainless Steel Bars and Shapes) govern the base bar material chemical composition and mechanical properties before thread rolling or cutting — the raw material specification that the threaded rod manufacturer certifies against before converting bar stock into finished threaded rod. Confirms the specific stainless grade (1.4301/304, 1.4401/316, 1.4571/316Ti) chemical composition limits.
NACE MR0175 / ISO 15156
For stainless threaded rod used in sour (H₂S-containing) service — process equipment studding, pressure-retaining flange studs in sour hydrocarbon service — NACE MR0175/ISO 15156 hardness limits and material qualification requirements apply, restricting cold-worked property class (high hardness from cold working can increase sulfide stress cracking susceptibility) and requiring specific heat treatment and hardness verification. Verify sour-service applicability before specifying high-strength cold-worked (Class 80) stainless threaded rod for sour process equipment studding.
Manufacturing Route
& Finish Options
Stainless steel threaded rod corrosion performance and mechanical integrity are determined by grade selection, thread-forming method, and post-manufacture surface treatment. RR Hydraulic advises on the correct grade and finish for each specific environmental exposure.
3.1 — Corrosion Resistance by Grade and Media
| Environment / Media | A2 (304) | A4 (316) | Duplex (2205) | Notes |
|---|---|---|---|---|
| Dry indoor atmosphere | Excellent | Excellent | Excellent | A2 fully adequate; A4/duplex unnecessary premium |
| Humid / mild outdoor atmosphere | Good | Excellent | Excellent | A2 acceptable away from coastal/industrial pollution |
| Coastal / marine atmosphere | Poor — pitting risk | Good | Excellent | A2 not recommended within several km of coastline |
| De-icing salt splash zone | Poor | Good | Excellent | A4 minimum for bridge/highway fastening in salt-exposed zones |
| Swimming pool / chlorinated environment | Unsuitable — known SCC risk | Caution — SCC risk at elevated humidity/temp | Suitable | Duplex or higher alloy recommended for pool roof/structure fixings per industry guidance |
| Dilute mineral acids | Limited | Moderate | Good | Confirm specific acid, concentration, and temperature with corrosion data |
| Food / beverage washdown (chloride-based sanitiser) | Marginal | Good | Excellent | A4 standard for food-contact-adjacent structural fastening |
| Hot chloride / under-insulation service | Poor — SCC risk | Poor — SCC risk above ~60°C | Good — significantly higher SCC resistance | Consider duplex for insulated hot piping hanger rods |
3.2 — Manufacturing Route: Rolled Thread vs. Cut Thread
Thread Rolling (Cold Forming)
The bar is passed between hardened thread-rolling dies that plastically deform the surface into the thread profile without removing material — the grain flow follows the thread contour, producing a work-hardened surface layer with improved fatigue strength and higher tensile capacity than an equivalent cut thread. Thread rolling is the standard production method for stainless threaded rod up to approximately M36–M42, and is required to achieve property class 70/80 cold-worked mechanical properties. Rolled threads also have a smoother root radius, reducing stress concentration compared to a cut thread.
Thread Cutting (Machining)
Material is removed by a die head or lathe to generate the thread profile — the grain flow is interrupted at the thread root, creating a stress concentration point with lower fatigue strength than a rolled thread of the same nominal dimensions. Thread cutting is used for large-diameter threaded rod beyond the practical rolling capacity of standard equipment (typically above M42), for custom or non-standard thread pitches, and for field modification/re-threading of stock bar where rolling equipment is not available. Cut-thread stainless rod is typically supplied in the solution-annealed (property class 50) condition since cutting does not impart the cold-working strengthening of rolling.
3.3 — Surface Finish Options
Mill Finish (As-Rolled/Cut)
The standard as-manufactured surface condition — clean, passivated stainless surface with no additional cosmetic treatment. Fully adequate corrosion performance for the base grade in its intended service environment; the standard finish for the majority of structural, HVAC, and process fastening applications where appearance is not a specification driver.
Passivation (ASTM A967 / AMS 2700)
Chemical treatment (typically dilute nitric or citric acid) that removes free iron contamination from the surface (introduced during machining, thread rolling, or handling) and promotes formation of a uniform, maximally protective chromium oxide passive layer. Passivation is a standard specified post-manufacturing step for stainless threaded rod in food-contact-adjacent, pharmaceutical, and high-corrosion-resistance-critical applications, verified by a passivation test (water-soak, high-humidity, salt spray, or copper sulfate test per ASTM A967) on sampled production lots.
Electropolishing
Electrochemical polishing process that removes a thin surface layer, reducing surface roughness (Ra) and enhancing the chromium-to-iron ratio at the surface for improved passive film quality and a bright, smooth cosmetic finish. Specified for pharmaceutical, semiconductor clean-room, and high-hygiene food-processing threaded rod applications where both maximum corrosion resistance and minimal surface adhesion (bacteria, particulate) are specification requirements — a premium finish beyond standard passivation.
PTFE / Fluoropolymer Coating
Thin fluoropolymer coating applied over the stainless substrate to reduce installation torque (lower thread friction), prevent galling during nut run-down (a known issue with austenitic stainless fasteners due to their tendency to gall/seize under high thread friction), and provide an additional barrier against aggressive chemical exposure. Specified where galling risk is a known field installation issue, particularly for larger-diameter A4 threaded rod and nut combinations installed without anti-seize compound.
3.4 — Straightness and Dimensional Tolerance
DIN 976-1 and equivalent standards specify a maximum permissible straightness deviation (bow) over the full length of the threaded rod — typically 1.5 mm per metre of length for standard commercial-grade threaded rod, tighter for precision applications. Excessive bow in long threaded rod (structural tie rods, long hanger rods) causes eccentric loading when the rod is placed in tension, introducing bending stress in addition to the intended axial load and reducing the effective working capacity below the calculated axial-only value. Straightness is verified by visual/mechanical check on production lots, with rejection or re-straightening of bar exceeding the tolerance before threading.
Industry Applications
& Documentation
RR Hydraulic maintains full traceability from certified bar stock heat to finished, tested, and packed stainless steel threaded rod shipment. Diameter and pitch gauging, property class verification, PMI, hardness, and complete export documentation are standard on all project-grade supply.
4.1 — Inspection & QC Protocol
4.2 — EN 10204 / Material Certification Requirements
| Certificate | Content | EPC Requirement | When Mandatory |
|---|---|---|---|
| 2.1 / 2.2 | Declaration / non-specific | Not acceptable for EPC critical fastening | Never for structural, pressure, or safety-class threaded rod |
| 3.1 (EN 10204) | Heat-traceable mech + chem | Mandatory — all EPC threaded rod | All structural, HVAC-support, and process fastening supply |
| 3.2 (EN 10204) | 3.1 + TPI countersign | Offshore critical; sour service; owner-specified critical items | Marine/offshore; sour process equipment; safety-critical structural anchors |
4.3 — Applications by Industry
Pipe Support and Hanger Rod Systems
A2 or A4 threaded rod (property class 70, M10–M20 typical) in double-nut hanger rod configurations for suspended pipe support systems in process plants, HVAC installations, and building services — stainless is specified in preference to galvanised carbon steel wherever the piping system carries corrosive fluid (potential leakage exposure to the hanger rod), operates in a washdown or high-humidity plant area, or where the project corrosion protection specification excludes zinc coatings for indefinite maintenance-free service life. For hot insulated piping hangers: verify insulation/vapour barrier integrity to prevent chloride-induced SCC risk under insulation.
Pressure Vessel and Heat Exchanger Flange Studding
A4/316 stainless threaded rod (studding) machined and cut to length for flange stud bolting on stainless or duplex process equipment, heat exchangers, and pressure vessels where the flange material itself is stainless and carbon steel studding (A193 B7) would introduce a dissimilar-metal galvanic couple at the stud/flange contact interface, or where the process specification requires full-stainless bolted joint construction for corrosion or hygiene reasons. Note: for ASME-code pressure-retaining bolting, A193 Class 2 stainless studs (B8/B8M) — not generic threaded rod — are typically the code-compliant product; confirm the specific application (pressure-retaining vs. non-pressure structural studding) before substituting generic stainless threaded rod for pressure equipment bolting.
Offshore and Marine Structural Fastening
A4-80 or duplex threaded rod for structural fastening on offshore platform topsides, marine vessel superstructure fixings, and coastal infrastructure where salt spray and chloride atmosphere would rapidly degrade A2/304 or galvanised carbon steel alternatives. Duplex threaded rod is increasingly specified for critical structural connections in the splash zone or in prolonged wet chloride exposure where standard A4 stress corrosion cracking risk under sustained structural load is a documented project engineering concern.
Food, Beverage, and Pharmaceutical Equipment
A4 passivated or electropolished threaded rod for equipment support structures, conveyor framework, and process vessel mounting in food, beverage, and pharmaceutical production facilities — the combination of corrosion resistance, cleanability (smooth passivated or electropolished surface resists bacterial adhesion), and compliance with hygienic design standards (EHEDG guidelines) makes A4 stainless the standard structural fastening material in these industries, in preference to both A2 stainless (chloride-based cleaning chemical exposure) and any coated carbon steel alternative.
Water and Wastewater Treatment Infrastructure
A2 (fresh water, mild chemical dosing areas) or A4 (chlorinated water, coastal-adjacent plants, aggressive chemical dosing zones) threaded rod for equipment mounting, walkway grating fixing, clarifier mechanism support, and chemical dosing skid structural fastening in municipal and industrial water/wastewater treatment plants — the combination of constant humidity, chemical exposure (chlorine, ferric chloride, polymer dosing chemicals), and the long design life expectation of treatment plant infrastructure favours stainless over coated carbon steel despite the higher initial material cost.
Architectural and Structural Facade Systems
A2 or A4 threaded rod (frequently in polished or brushed finish where visible) for architectural facade panel support, glazing systems, and exposed structural connections where both corrosion resistance and aesthetic appearance are specification drivers. Coastal or high-pollution urban facade applications specify A4 over A2 to prevent surface staining and pitting that would compromise both the structural integrity and the architectural appearance of exposed fastening hardware over the building’s design life.
4.4 — Installation Torque Reference
| Size | Property Class 70 Torque (N·m) | Property Class 80 Torque (N·m) | Notes |
|---|---|---|---|
| M8 | 13 | 15 | Anti-seize / lubricant mandatory — high galling risk |
| M10 | 26 | 30 | Anti-seize / lubricant mandatory |
| M12 | 45 | 52 | Anti-seize / lubricant mandatory |
| M16 | 110 | 127 | Controlled, moderate installation speed to avoid galling |
| M20 | 215 | 247 | Torque wrench verification recommended for structural joints |
| M24 | 370 | — | Class 80 typically unavailable at this diameter — verify with manufacturer |
Indicative values for engineering reference only — final installation torque must be calculated per the applicable structural or mechanical design code for the specific joint, gasket/washer configuration (where present), lubricant condition, and required preload, and verified at site with a calibrated torque tool.
4.5 — Export Packaging Specification
- Threaded rod supplied in standard mill lengths (1 m or 3 m) or custom-cut lengths, bundled and strap-bound with thread-end protection (plastic caps or thread protectors) at both ends to prevent thread damage during transit and handling
- Passivated or electropolished rod individually sleeved in protective film or paper wrap within bundles to prevent surface contact marking and preserve the finish quality through transit and site storage
- Stainless threaded rod segregated from carbon steel, galvanised, and other ferrous hardware in all packaging and storage — cross-contamination from carbon steel particles (e.g., from a shared cutting or grinding surface) embeds in the stainless surface and initiates localized rust staining (“free iron contamination”) that compromises the passive film and corrosion performance
- Heat/lot number marked on each bundle label and cross-referenced on the packing list — stainless grades (A2 vs A4) are not reliably distinguishable by visual appearance alone; heat number traceability is essential for site QA verification against the material certificate
- ISPM-15 timber or export cartons; documentation in a waterproof pocket: EN 10204 3.1/3.2 MTC, dimensional and thread gauging report, mechanical test report (tensile/proof load), PMI report, passivation certificate (where applicable), hardness report, and packing list with grade/property-class/length breakdown per item
4.6 — Complete Documentation Package for EPC Project Supply
| # | Document | Standard / Format | Mandatory / Conditional | Notes |
|---|---|---|---|---|
| 01 | Material Test Certificate | EN 10204 3.1 / 3.2 | Mandatory — all EPC supply | Heat-traceable; chemical + mechanical results |
| 02 | Chemical Composition Report | EN 10088 / ASTM A276 grade limits | Mandatory | Confirms A2/304 vs A4/316 vs 316Ti composition |
| 03 | Mechanical Properties Report | ISO 3506-1 / ASTM F606 | Mandatory | Tensile strength, proof load, elongation per property class |
| 04 | Thread Gauging Report | ISO 1502 / ASME B1.2 | Mandatory | Go/No-Go verification; pitch diameter |
| 05 | Dimensional Inspection Report | DIN 976-1 / project tolerance | Mandatory | Diameter, length, straightness |
| 06 | PMI Report (XRF) | Per project QA/QC procedure | Mandatory — critical / offshore / sour supply | Grade verification per lot |
| 07 | Passivation Certificate | ASTM A967 | Conditional — food/pharma/high-corrosion-resistance orders | Water-soak / salt spray / copper sulfate test result |
| 08 | Hardness Test Report | ASTM E18 / ISO 6508 | Mandatory — sour service; conditional otherwise | Confirms cold-worked condition and NACE compliance where applicable |
| 09 | NACE MR0175 Compliance Declaration | ISO 15156 Parts 2/3 | Conditional — sour service studding | Hardness and material qualification statement |
| 10 | First Article Inspection (FAI) Report | Project-specific format | Mandatory — new project specifications | All parameters; before batch production |
| 11 | TPI Witness Certificate | SGS / BV / DNV / Lloyd’s | Conditional — offshore; safety-critical structural | Co-witness dimensional + mechanical + PMI |
| 12 | ISO 9001:2015 Certificate | Third-party QMS certification | Mandatory — EPC projects | Scope covers threaded rod manufacture |
| 13 | Country of Origin + Packing List | Chamber of Commerce / item-level | Mandatory | HS tariff code; grade and property class on packing list per item |
| 14 | Commercial Invoice + Bill of Lading | Per INCOTERMS 2020 | Mandatory | Freight forwarder issued |
Submit your diameter, thread form, grade, property class, length, and quantity to RR Hydraulic for a complete, certified commercial offer.