Eye Lag Bolt

1. Industry Context

1.1 Role of Eye Lag Bolts in Industrial Fastening Systems

Eye Lag Bolts represent a specialized load-attachment fastener category designed for:

• Structural suspension
• Lifting restraint systems
• Cable anchoring
• Safety tie-off points
• Mechanical retention assemblies

Unlike conventional bolts that clamp components together, the primary function of an Eye Lag Bolt is:

To transfer tensile or angular loads from a connected component into a structural substrate.

The fastener combines:

• Lag screw anchorage principles
• Integrated forged lifting eye geometry
• Threaded wood or masonry engagement

They are widely used where direct anchoring without nut access is required.

1.2 Industrial Usage Environment

Eye Lag Bolts are routinely specified in:

Industry Sector	Functional Purpose
Structural Steel & Construction	Cable support, signage suspension
Oil & Gas	Instrument lines, hose restraint
Power Generation	Cable trays, lighting supports
Petrochemical Plants	Pipe hanger systems
LNG & Offshore	Secondary retention anchoring
Railways & Infrastructure	Overhead equipment support
Shipbuilding	Deck rigging points
Heavy Equipment	Temporary lifting anchorage

Engineers select Eye Lag Bolts where installation accessibility is limited but reliable anchorage is mandatory.

1.3 Functional Difference from Similar Fasteners

Fastener Type	Load Function	Key Difference
Eye Bolt	Through-bolt lifting	Requires nut
Shoulder Eye Bolt	Precision lifting	Machined seating required
J Bolt	Embedded anchorage	Cast-in installation
Expansion Anchor	Concrete fixation	Expansion mechanism
Eye Lag Bolt	Direct substrate anchoring	Self-threading anchorage

Eye Lag Bolts eliminate:

• Back-side access requirements
• Through-hole drilling
• Additional hardware components

1.4 Procurement Perspective in EPC Projects

EPC procurement teams evaluate Eye Lag Bolts based on:

• Load rating verification
• Material traceability
• Corrosion performance
• Thread standard compatibility
• Inspection certification availability

As an ISO 9001–controlled manufacturer, SM Fasteners integrates:

• Material traceability
• Batch control
• Mechanical verification
• EN 10204 documentation readiness

ensuring suitability for audited projects.

2. Technical Definition

2.1 Engineering Definition

An Eye Lag Bolt is defined as:

A forged or machined fastener incorporating an integral circular eye and external lag screw threads intended for anchoring into wood, concrete inserts, or engineered structural substrates to support tensile or angular loads.

2.2 Basic Components

Component	Engineering Function
Eye Loop	Load transfer interface
Shoulder Transition	Stress distribution zone
Shank	Structural load path
Lag Thread	Substrate engagement
Tip	Installation penetration

2.3 Geometry Characteristics

Key geometric parameters influencing performance:

• Eye internal diameter
• Eye cross-section thickness
• Shank diameter
• Thread depth
• Embedded thread length
• Root radius transition

Proper geometry prevents:

• Stress concentration
• Eye deformation
• Thread stripping failure

2.4 Typical Installation Substrates

• Timber beams
• Laminated structural wood
• Concrete (with inserts)
• Steel via tapped bosses
• Composite industrial structures

2.5 Load Classification

Eye Lag Bolts primarily experience:

• Axial tension
• Angular tension
• Cyclic loading
• Dynamic vibration forces

They are not intended for high bending loads unless specifically engineered.

3. Load Mechanics & Force Behavior

3.1 Load Transfer Mechanism

Load transfer occurs through three sequential paths:

1. Load enters eye
2. Force travels through shank
3. Thread shear transfers load to substrate

Load → Eye → Shank → Thread Engagement → Base Material

3.2 Primary Load Types

Load Type	Behavior
Pure Tension	Ideal loading condition
Angular Load	Reduced capacity
Shear	Secondary resistance
Dynamic Load	Fatigue governing
Shock Load	Requires safety factor

3.3 Tensile Force Mechanics

Ultimate performance depends on:

• Thread engagement depth
• Material yield strength
• Substrate density
• Installation torque

Tensile capacity:$$F_t = A_s \times \sigma_y$$

Where:

• $A_s$​ = tensile stress area
• $\sigma_y$​ = yield strength

3.4 Thread Anchorage Mechanics

Lag threads develop holding strength through:

• Thread flank bearing
• Wood or insert compression
• Frictional resistance

Failure modes:

• Pull-out failure
• Substrate splitting
• Thread stripping

3.5 Effect of Load Angle

Allowable load decreases significantly with angle.

Load Angle	Capacity Reduction
0° (Vertical)	100%
30°	~85%
45°	~70%
60°	~50%
90°	Not recommended

Engineering practice requires:

• Vertical loading whenever possible
• Swivel connectors for angular alignment

3.6 Stress Concentration Zones

Critical stress regions:

1. Eye-to-shank transition
2. First engaged thread
3. Root of thread profile

Forged eyes offer superior fatigue resistance compared to welded eyes.

SM Fasteners manufactures precision-forged configurations minimizing stress risers.

3.7 Friction & Torque–Tension Relationship

Torque applied during installation generates preload:

$$T = K \times F \times D$$

Where:

• T = Torque
• K = Nut factor
• F = Preload
• D = Diameter

Lag bolts rely partly on:

• Thread cutting resistance
• Frictional compression

3.8 Preload Behavior

Proper preload ensures:

• Reduced micro-movement
• Improved fatigue resistance
• Stable load transfer

Under-tightening → loosening
Over-tightening → substrate failure

4. Joint Design Principles

4.1 Engineering Design Objectives

Joint design using Eye Lag Bolts must achieve:

• Secure anchorage
• Controlled load direction
• Long-term fatigue resistance
• Corrosion durability

4.2 Minimum Thread Engagement

Recommended engagement:

Substrate	Minimum Engagement
Softwood	8 × diameter
Hardwood	6 × diameter
Steel insert	1.5 × diameter
Concrete insert	Manufacturer rating

4.3 Edge Distance Requirements

Improper placement causes substrate cracking.

Parameter	Recommended Minimum
Edge distance	4 × diameter
Spacing between bolts	6 × diameter
End distance	7 × diameter

4.4 Design Safety Factors

Industrial standards typically apply:

Application	Safety Factor
Static load	3:1
Dynamic load	5:1
Lifting applications	6:1 minimum

4.5 Thread Engagement Efficiency

Effective load capacity depends on:

• Thread depth
• Pitch geometry
• Substrate modulus

Full capacity achieved only when:$$L_e \geq Required\ Engagement$$

4.6 Failure Mechanisms in Service

1. Fatigue Failure

Caused by cyclic loading at eye transition.

2. Shear Failure

Occurs when load applied laterally.

3. Hydrogen Embrittlement

Risk in high-strength electroplated fasteners.

4. Stress Corrosion Cracking

Observed in chloride or H₂S environments.

SM Fasteners controls these risks via:

• Material selection
• Heat treatment control
• Certified coating processes

4.7 Installation Engineering Considerations

Engineers must verify:

• Correct pilot hole diameter
• Alignment during tightening
• Torque monitoring
• Substrate integrity

Incorrect installation accounts for the majority of field failures.

4.8 Compatibility with Advanced Materials (Including PEEK Systems)

In chemical or electrical isolation applications:

• PEEK washers
• PEEK spacers
• Hybrid metal-PEEK assemblies

may be integrated with Eye Lag Bolts supplied by SM Fasteners for:

Cryogenic stability

Electrical insulation

Chemical resistance

Weight reduction

5. Product Types and Variants

Eye Lag Bolts are produced in multiple engineered configurations to meet load orientation, installation conditions, and environmental exposure requirements.

Unlike standardized hex bolts, Eye Lag Bolts combine anchoring mechanics with load attachment geometry, resulting in several functional variants.

5.1 Classification by Eye Geometry

5.1.1 Standard Round Eye Lag Bolt

• Circular forged eye
• General suspension applications
• Accepts hooks, shackles, chains

Typical Uses

• Cable support
• Light mechanical suspension
• Structural tie-offs

5.1.2 Heavy Pattern Forged Eye Lag Bolt

• Increased eye cross-section
• Improved fatigue resistance
• Higher shock load tolerance

Used in:

• Oil & gas facilities
• Offshore structures
• Power plants

5.1.3 Long Shank Eye Lag Bolt

• Extended unthreaded section
• Allows standoff mounting

Applications:

• Pipe hangers
• Cable trays
• Insulated panels

5.1.4 Closed Safety Eye Design

• Reduced eye opening tolerance
• Prevents accidental disengagement

Common in:

• Safety restraint systems
• Rail infrastructure
• Temporary lifting restraints

5.1.5 Welded Eye Lag Bolt (Special Fabrication)

Used only when forging constraints exist.

⚠ Engineering Note:
Welded eyes exhibit reduced fatigue life compared to forged configurations and require additional NDT inspection.

SM Fasteners prioritizes precision forging to maintain grain continuity and eliminate weld defects.

5.2 Classification by Thread Type

Thread Type	Application
Coarse Lag Thread	Timber anchorage
Deep Wood Thread	Softwood applications
Machine Thread	Steel inserts
Dual Thread	Hybrid installations
Self-tapping Lag	Composite panels

5.3 Classification by Installation Method

Type	Installation Method
Manual Installation	Wrench through eye
Rod Assisted Installation	Steel bar used for leverage
Pre-installed Insert Type	Concrete anchor systems
Chemical Anchor Compatible	Resin bonded inserts

5.4 Custom Engineered Variants (SM Fasteners Capability)

SM Fasteners manufactures project-specific designs including:

• Oversized lifting eyes
• Offshore corrosion-resistant variants
• High-temperature eye lag bolts
• Cryogenic-service fasteners
• PEEK-integrated insulated assemblies

Custom engineering includes:

• Load validation
• Finite element geometry optimization
• Drawing approval before production

6. Dimensional Logic and Geometry

Eye Lag Bolt performance depends strongly on dimensional relationships rather than diameter alone.

6.1 Primary Dimensional Parameters

Symbol	Description
d	Nominal shank diameter
L	Overall length
Le	Thread engagement length
Di	Eye internal diameter
Do	Eye outer diameter
t	Eye thickness
P	Thread pitch

6.2 Engineering Dimensional Principles

Eye Diameter Selection

Must allow free articulation without side loading.

Recommended:$$D_i ≥ 1.25 \times Hook\ Diameter$$

Eye Thickness Requirement

Eye thickness governs fatigue life.$$t ≥ 0.35d \text{ (minimum)}$$

Thread Engagement Rule

$$L_e ≥ 6d \text{ (minimum structural anchorage)}$$

6.3 Standard Dimensional Specification Table

(Typical SM Fasteners Production Range)

Size	Thread Pitch	Overall Length (mm)	Thread Length (mm)	Eye ID (mm)	Eye OD (mm)	Eye Thickness (mm)
M6	1.0	60–120	40	12	20	4
M8	1.25	80–160	50	16	26	5
M10	1.5	100–200	65	20	32	6
M12	1.75	120–250	80	24	38	7
M16	2.0	160–300	100	30	48	9
M20	2.5	200–400	130	38	60	12
M24	3.0	250–450	150	45	72	14
M30	3.5	300–600	180	55	88	18

(All dimensions configurable per project drawings.)

6.4 Weight Chart — SM Fasteners Reference

Size	Weight / Piece (kg)	Weight / 100 pcs (kg)
M6	0.03	3
M8	0.06	6
M10	0.10	10
M12	0.18	18
M16	0.35	35
M20	0.70	70
M24	1.20	120
M30	2.30	230

Used by EPC buyers for logistics planning and freight estimation.

7. Applicable International Standards

Eye Lag Bolts combine requirements from multiple standards since no single universal standard fully defines them.

7.1 ISO Standards

Standard	Scope
ISO 898-1	Mechanical properties of steel fasteners
ISO 3506	Stainless steel fasteners
ISO 965	Thread tolerances
ISO 3269	Acceptance inspection
ISO 4759	Dimensional tolerances

7.2 ASTM Standards

Standard	Application
ASTM A307	Carbon steel bolts
ASTM A193	High-temperature alloy fasteners
ASTM A320	Low-temperature service
ASTM F593	Stainless steel bolts
ASTM B574	Nickel alloy fasteners

7.3 DIN Standards (Common References)

DIN Standard	Description
DIN 580	Lifting eye bolts (reference geometry)
DIN 7990	Structural bolting
DIN 267	Fastener technical delivery conditions

7.4 British Standards (BS)

BS Standard	Description
BS 3692	ISO metric bolts
BS 4190	Metric bolt dimensions
BS EN 14399	High-strength structural fasteners

7.5 Thread Standards & Tolerances Table

Thread System	Designation	Typical Tolerance
Metric Coarse	M	6g / 6H
UNC	Unified Coarse	2A / 2B
UNF	Unified Fine	2A / 2B
BSW	Whitworth	Medium fit
BSF	Fine Whitworth	Close fit

SM Fasteners supplies all global thread systems to ensure interchangeability across international projects.

8. Mechanical Properties — Grade Wise

8.1 Carbon & Alloy Steel Property Classes

Property Class	Yield Strength (MPa)	Tensile Strength (MPa)	Typical Application
4.6	240	400	Light structural
5.8	400	500	General anchorage
8.8	640	800	Structural duty
10.9	940	1040	Heavy industrial
12.9	1100	1220	High-load engineering

8.2 Stainless Steel Grades

Grade	UTS (MPa)	Corrosion Resistance	Environment
A2-70	700	Excellent	Outdoor
A4-70	700	Marine resistant	Offshore
A4-80	800	Superior	Chemical plants

9. Proof Load & Tensile Strength Table

Size	Stress Area (mm²)	Proof Load 8.8 (kN)	Ultimate Load (kN)
M8	36.6	23	29
M10	58	37	47
M12	84.3	54	67
M16	157	100	125
M20	245	157	196
M24	353	226	283
M30	561	359	449

Values depend on material grade and substrate capacity.

10. Engineering Interchangeability Considerations

Procurement teams must verify:

• Thread compatibility
• Eye geometry clearance
• Load rating equivalence
• Certification traceability

Interchangeability risks arise when:

• Metric bolts replace UNC threads
• Forged eyes substituted with welded eyes
• Material grade downgraded without approval

SM Fasteners ensures project compliance through:

• Drawing-controlled manufacturing
• Batch traceability
• Material verification aligned with ISO 9001 quality systems.

11. Material Grades and Selection Criteria

Material selection for Eye Lag Bolts directly determines:

• Load carrying capacity
• Corrosion resistance
• Temperature capability
• Fatigue life
• Compliance with oil & gas specifications

Engineering selection must consider mechanical loading + environmental exposure simultaneously.

11.1 Carbon Steel Fasteners

Typical Grades

• ASTM A307
• IS 1367
• Property Class 4.6 / 5.8 / 8.8

Characteristics

• High strength-to-cost ratio
• Suitable for indoor structural anchoring
• Requires protective coating

Applications

• Structural steel frameworks
• Industrial buildings
• Cable suspension systems

11.2 Alloy Steel Eye Lag Bolts

Typical Materials:

• ASTM A193 B7
• AISI 4140 / 4340
• Property Class 10.9 / 12.9

Advantages

• High tensile strength
• Superior fatigue resistance
• Elevated temperature capability

Used in:

• Power plants
• Petrochemical facilities
• Heavy machinery anchorage

11.3 Stainless Steel Grades

Grade	Equivalent	Key Advantage
SS304	A2	General corrosion resistance
SS316	A4	Marine & chloride resistance
SS316L	Low carbon	Weld decay resistance
Duplex 2205	UNS S32205	High strength + corrosion resistance
Super Duplex 2507	UNS S32750	Offshore & seawater service

11.4 Nickel Alloy & Exotic Materials

SM Fasteners supplies advanced alloys for critical projects:

• Hastelloy C276
• Inconel 625 / 718
• Incoloy 825
• Monel 400
• Nickel 200/201
• SMO 254

These materials resist:

• Chloride stress corrosion cracking
• Sour gas exposure
• Acidic chemical environments
• High temperature oxidation

11.5 PEEK Fastener Integration

For specialized assemblies, Eye Lag Bolts may incorporate:

• PEEK bushings
• PEEK washers
• Hybrid metal-polymer isolation systems

Benefits:

• Electrical insulation
• Chemical inertness
• Cryogenic compatibility
• Weight reduction

Used in:

• LNG systems
• Electrical installations
• Semiconductor plants
• Chemical processing equipment

11.6 Material Selection Matrix

Environment	Recommended Material
Indoor dry	Carbon steel 8.8
Outdoor industrial	SS304 / coated steel
Marine offshore	SS316 / Duplex
Chemical plant	Hastelloy / SMO 254
Sour service (H₂S)	NACE compliant alloy
High temperature	Inconel
Cryogenic	Austenitic stainless

12. Mechanical Properties — Material Comparison Table

Material	UTS (MPa)	Yield (MPa)	Temp Limit	Corrosion Resistance	Relative Cost	Typical Industry
Carbon Steel	400–800	240–640	300°C	Low	Low	Construction
Alloy Steel	900–1200	800+	450°C	Moderate	Medium	Power/Oil
SS304	~700	~450	870°C	High	Medium	Infrastructure
SS316	~700	~450	900°C	Very High	Medium-High	Offshore
Duplex	800–900	550	300°C	Excellent	High	Marine
SMO 254	650	300	400°C	Extreme	Very High	Chemical
Inconel 625	900	450	1000°C	Extreme	Premium	Aerospace/LNG
PEEK	—	—	260°C	Chemical inert	High	Electrical

13. Heat Treatment Processes

Heat treatment controls final mechanical performance.

13.1 Heat Treatment Objectives

• Increase strength
• Improve toughness
• Control hardness
• Reduce residual stress
• Enhance fatigue resistance

13.2 Standard Heat Treatment Routes

Quenching & Tempering

Used for grades 8.8, 10.9, 12.9.

Process:

1. Austenitizing
2. Oil quenching
3. Controlled tempering

Result:

• High strength
• Stable microstructure

Solution Annealing (Stainless Steel)

Applied to:

• SS304
• SS316
• Duplex alloys

Benefits:

• Restores corrosion resistance
• Eliminates carbide precipitation

Age Hardening (Nickel Alloys)

Used for:

• Inconel 718
• Precipitation-strengthened alloys

Improves:

• High-temperature strength
• Creep resistance

13.3 Hardness Control (Critical Requirement)

Grade	Hardness Range
8.8	22–32 HRC
10.9	32–39 HRC
12.9	39–44 HRC
Stainless	≤ 300 HV

Sour Service Requirement

(NACE MR0175 / ISO 15156)

Maximum hardness typically:$$≤ 22 HRC$$

to prevent sulfide stress cracking.

SM Fasteners provides controlled heat treatment with certified hardness verification.

14. End-to-End Manufacturing Workflow

Eye Lag Bolts require a combination of forging accuracy and thread precision.

14.1 Raw Material Verification

Incoming inspection includes:

• Mill Test Certificate (MTC)
• Heat number verification
• Chemical composition analysis
• PMI testing (when required)

14.2 Manufacturing Flow

Raw Material → Cutting → Forging → Eye Formation
→ Normalizing → Machining → Thread Rolling
→ Heat Treatment → Surface Finish → Inspection → Packaging

14.3 Forging vs Machining

Method	Advantage
Hot Forging	Grain flow continuity
Closed Die Forging	High fatigue resistance
CNC Machining	Precision custom geometry

Forged eyes are strongly preferred for load-bearing applications.

14.4 Eye Formation Process

Critical manufacturing step:

• Upset forging
• Controlled bending
• Radius forming

Engineering objective:

Eliminate weld joints and micro-cracks.

14.5 Thread Manufacturing

Thread Rolling (Preferred)

Benefits:

• Increased fatigue strength
• Compressive surface stress
• Better dimensional accuracy

Thread Cutting

Used only for:

• Large diameters
• Exotic alloys

14.6 Traceability System

ISO 9001 manufacturing control includes:

• Batch identification
• Heat number stamping
• Production traveler records
• Inspection checkpoints

15. Surface Finishing & Coatings

Surface engineering determines service life.

15.1 Coating Types

Coating	Thickness	Corrosion Resistance	Application
Black Oxide	Minimal	Low	Indoor
Zinc Plated	5–12 µm	Moderate	General industry
Hot Dip Galvanized	70–100 µm	High	Construction
Mechanical Galvanized	Uniform	High	Structural
PTFE / Xylan	Low friction	Excellent	Chemical plants
Dacromet / Geomet	Non-electrolytic	Very High	Offshore
Passivation	Chemical film	Stainless protection	Marine
Nickel Plating	Decorative + corrosion	Moderate	Equipment

15.2 Surface Finish Performance Comparison

Finish	Salt Spray Resistance	Hydrogen Embrittlement Risk	Temperature Limit
Zinc Electroplate	96–240 hr	High	120°C
HDG	720+ hr	Low	300°C
Dacromet	1000+ hr	Very Low	300°C
PTFE	Excellent	None	260°C
Passivated SS	Excellent	None	800°C

15.3 Hydrogen Embrittlement Control

Critical for high-strength Eye Lag Bolts.

Preventive measures:

• Non-electrolytic coatings
• Post-bake treatment
• Hardness control
• Process validation

SM Fasteners applies controlled coating procedures aligned with ISO quality systems.

15.4 Surface Engineering Selection Guide

Environment	Recommended Finish
Indoor	Zinc plated
Outdoor	HDG
Marine	SS316 / Duplex
Offshore	Dacromet / Geomet
Chemical	PTFE coated
High temperature	Passivated stainless

16. Inspection & Quality Control

Eye Lag Bolts used in industrial projects must comply with auditable quality assurance systems.
Failure typically originates from inadequate inspection rather than material deficiency.

SM Fasteners integrates inspection controls aligned with ISO 9001 quality management systems ensuring complete traceability.

16.1 Inspection Philosophy

Quality verification follows three stages:

1. Incoming Material Inspection
2. In-Process Manufacturing Control
3. Final Release Inspection

16.2 Dimensional Inspection

Measured parameters include:

• Eye internal diameter
• Eye concentricity
• Shank diameter
• Thread pitch & form
• Thread length
• Overall length
• Surface integrity

Inspection Equipment

• Vernier & digital micrometers
• Thread plug gauges
• Optical comparators
• Profile projectors
• Coordinate measuring machines (CMM)

16.3 Mechanical Testing

Test	Standard Reference	Purpose
Tensile Test	ISO 898 / ASTM A370	Strength verification
Proof Load Test	ISO 898	Elastic limit validation
Hardness Test	ISO 6508	Heat treatment confirmation
Bend Test	Internal procedure	Eye integrity
Load Simulation	Project specific	Functional verification

16.4 Non-Destructive Testing (NDT)

Critical for forged lifting components.

Method	Application
Magnetic Particle Inspection (MPI)	Surface cracks
Dye Penetrant Testing (PT)	Eye transition defects
Ultrasonic Testing (UT)	Internal discontinuities
Radiography	Special critical orders

Forged eyes undergo focused inspection at stress concentration zones.

16.5 Positive Material Identification (PMI)

Required for:

• Duplex
• Super Duplex
• Nickel alloys
• Sour service applications

PMI verifies alloy chemistry against MTC data.

16.6 Documentation & Certification

SM Fasteners supplies full EPC documentation:

Document	Standard
Mill Test Certificate	EN 10204 3.1
Third Party Certification	EN 10204 3.2
Heat Treatment Report	Mandatory
Dimensional Inspection Report	Included
Coating Thickness Report	Included
Certificate of Conformity	Provided
NDT Reports	When specified

17. Failure Mechanisms & Engineering Risk Control

17.1 Fatigue Failure

Causes:

• Cyclic loading
• Improper eye geometry
• Surface defects

Control:

• Forged eye design
• Rolled threads
• Correct preload

17.2 Shear Failure

Occurs when side loading replaces axial loading.

Engineering rule:

Eye Lag Bolts are primarily tension devices.

17.3 Hydrogen Embrittlement

Risk Factors:

• Electroplating
• High hardness steels (>39 HRC)

Mitigation:

• Baking procedures
• Controlled plating
• Alternative coatings

17.4 Stress Corrosion Cracking

Common in:

• Chloride environments
• H₂S service

Mitigation:

• Duplex or nickel alloy materials
• NACE MR0175 compliance

18. Industry Applications

Eye Lag Bolts supplied by SM Fasteners serve critical roles across global industries.

18.1 Construction & Structural Steel

• Suspended services
• Cable routing
• Temporary structural restraint
• Signage anchoring

18.2 Oil & Gas (Upstream–Midstream–Downstream)

Applications include:

• Hose restraint anchorage
• Instrument support
• Secondary lifting restraint
• Safety cable installations

Materials:

• A193 B7
• SS316
• Duplex 2205
• NACE compliant alloys

18.3 Power Generation

• Turbine hall cable suspension
• Lighting systems
• HVAC support anchoring

High-temperature alloys supplied where required.

18.4 Petrochemical & Chemical Processing

Requirements:

• Chemical resistance
• Anti-galling threads
• Corrosion-resistant coatings

Typical materials:

• Hastelloy
• SMO 254
• PTFE-coated assemblies

18.5 LNG & Offshore Installations

Engineering priorities:

• Seawater corrosion resistance
• Low-temperature toughness
• Fatigue resistance

Recommended materials:

• Super Duplex
• Inconel
• A4 stainless steel

18.6 Railways & Infrastructure

• Overhead cable systems
• Bridge service supports
• Signaling equipment anchorage

18.7 Shipbuilding & Marine Engineering

• Deck equipment restraint
• Safety tethering
• Rigging systems

18.8 Automotive & Heavy Equipment Manufacturing

• Transport securing points
• Maintenance lifting anchors
• Assembly retention fixtures

18.9 PEEK Fastener Applications

Where metal isolation is required:

• Electrical switchgear
• Semiconductor manufacturing
• Chemical reactors
• Cryogenic LNG equipment

SM Fasteners integrates PEEK fastener components with metallic Eye Lag Bolt assemblies.

19. Export Capability & Global Supply Readiness

SM Fasteners supports international EPC procurement programs.

19.1 Industrial Packaging

Standard packaging methods:

• VCI corrosion protection
• Thread caps & protectors
• Batch identification labels
• Moisture barrier packaging

19.2 Export Crating

• ISPM-15 compliant wooden crates
• Vacuum sealing (marine shipment)
• Palletized bulk export packing

19.3 Logistics Documentation

Provided with shipment:

• Packing list
• Commercial invoice
• Certificate of Origin
• Inspection release note
• Material traceability documents

19.4 Global Procurement Advantages

SM Fasteners supports:

• Custom drawings
• Low & high volume production
• Project-based manufacturing
• Multi-material capability
• Rapid export coordination

20. Tightening Torque Chart

(Typical reference values — lubricated condition, property class 8.8)

Size	Torque (Nm) Dry	Torque (Nm) Lubricated
M8	25	18
M10	49	34
M12	86	60
M16	210	150
M20	410	290
M24	710	500
M30	1420	1000

Actual torque must consider substrate strength.

21. Preload Calculation

Formula

$$F = \frac{T}{K \times D}$$

Where:

• F = Preload force
• T = Applied torque
• K = Nut factor (≈0.18 lubricated)
• D = Nominal diameter

Worked Example

Given:

• Bolt Size: M16
• Torque = 150 Nm
• Nut Factor = 0.18
• Diameter = 0.016 m

$$F = \frac{150}{0.18 \times 0.016}$$

$$F = 52,083 \text{ N}$$

Approximate preload = 52 kN

22. Corrosion Resistance vs Environment

Environment	Recommended Material	Coating
Indoor Dry	Carbon Steel	Zinc
Outdoor Industrial	SS304	Passivation
Marine Atmosphere	SS316	Passivation
Offshore Splash Zone	Duplex	Dacromet
Acidic Chemical	Hastelloy	PTFE
Sour Gas H₂S	NACE Alloy	Controlled hardness
Cryogenic	Austenitic SS	None required

23. Surface Finish Performance Comparison

Finish	Corrosion Resistance	Maintenance	Typical Use
Zinc Plating	Moderate	Medium	General
Hot Dip Galvanized	High	Low	Structural
PTFE	Very High	Low	Chemical
Dacromet	Extreme	Low	Offshore
Passivated Stainless	Excellent	Minimal	Marine

24. Thread Standards & Tolerances

Thread	Standard	Fit
Metric	ISO 965	6g
UNC	ASME B1.1	2A
UNF	ASME B1.1	2A
BSW	BS 84	Medium
BSF	BS 84	Close

SM Fasteners supplies interchangeable threading for multinational EPC projects.

25. Engineering Weight Reference Table

(Aligned with SM Fasteners manufacturing data)

Size	Weight / Piece (kg)	Weight / 100 pcs (kg)
M6	0.03	3
M8	0.06	6
M10	0.10	10
M12	0.18	18
M16	0.35	35
M20	0.70	70
M24	1.20	120
M30	2.30	230

Used for freight calculation and structural dead-load analysis.

26. Engineering Selection Checklist (Procurement Ready)

✔ Verify load direction
✔ Confirm material grade
✔ Check corrosion environment
✔ Validate standards compliance
✔ Confirm thread compatibility
✔ Review inspection documentation
✔ Ensure traceability certification
✔ Confirm coating suitability

27. Integrated Manufacturing & Quality Positioning

Through certified manufacturing and engineering control,
SM Fasteners demonstrates capability across:

• Precision forging
• Advanced materials engineering
• Controlled heat treatment
• Certified inspection systems
• Global export compliance

Supporting industries including:

• Construction
• Oil & Gas
• Power Generation
• Petrochemical
• Offshore & LNG
• Infrastructure
• Heavy Engineering OEMs

End of Engineering Reference — Eye Lag Bolt

This four-part document establishes SM Fasteners as a:

• Standards-compliant manufacturer
• Engineering-driven fastener supplier
• Globally reliable EPC procurement partner
• Advanced materials and custom fastener specialist