Zinc Plated eye lag screws
Forged steel eyes that won't bend or break.
17,500 lbs breaking strength for critical loads.
Direct thread into wood. No nuts required.
01
Sinsun Eye Lag Screws: Engineered Lifting Points for Wood Structures
Standard hardware doesn't work when you need to hang something from wood. This includes stabilizing a tree with cable, hanging acoustic ceiling, or anchoring heavy equipment. The eye opens. The threads come off. The load went down.
Sinsun makes eye-lag screws that are suitable for anchoring wood. Sinsun eye lags are hot-forged from a single piece of steel, unlike bent wire screw eyes that bend when subjected to weight. The eye and shank are made of one solid piece of grain, which eliminates the weak points where bent eyes break apart.
This guide is based on breaking strength data, material science, and more than 30 years of experience in the field. This is in arborist, construction, and industrial settings. Sinsun gives your project the stability it needs, whether you're wiring up a hundred-year-old oak tree or hanging a grand ceiling.
What is a screw with an eye?
An eye lag screw, also known as a lag eye screw, lag eye bolt, or eye lag, is a strong fastener made to provide a safe place to lift or anchor something in wood.
It has a wood-threaded lag screw shank and a looped eye at the head, so ropes, cables, hooks, or hardware can attach directly to wooden structures.
How Does It Work?
Eye lag screws don't need a nut on the other side like machine-taped eye bolts do. Instead, they thread directly into the wood. The rough threads cut into the wood fibers, creating a mechanical bond that keeps the wood from coming out. The eye stays open so it can be used as a connection point.
| Construction Type | Manufacturing Process | Load Capacity | Failure Mode | Sinsun Offering |
| Bent Wire (Standard Screw Eye) | Wire bent into loop | Light duty only (under 200 lbs) | Eye opens under load | Not recommended |
| Forged (Sinsun Pro Series) | Single-piece hot forging | 11,000 - 17,500 lbs | Thread stripping (eye remains closed) | Standard |
| Welded Assembly | Eye welded to shank | Medium duty | Weld fails at heat-affected zone | Not manufactured |
The Sinsun Difference: Every Sinsun eye lag screw is hot-forged from high-carbon or stainless steel. The grain structure flows continuously through the eye and shank, delivering true rated capacity without the risk of the eye pulling open
Sinsun Eye Lag Screws: Complete Technical Specifications
This comprehensive technical reference covers all Sinsun Eye Lag Screw series, including heavy-duty forged models for structural applications, ceiling grid variants for acoustical installations, and marine-grade stainless steel options.
| Series | Description | Primary Applications | Diameter Range | Length Range | Material Options |
| Sinsun Forged Heavy-Duty (HDE) | Hot-forged single-piece construction | Tree cabling, guy wires, industrial rigging | 1/2" to 5/8" | 3-1/4" to 4" | HDG Carbon Steel |
| Sinsun Marine Grade (SEL) | Forged 316 stainless steel | Coastal decks, docks, saltwater exposure | 1/4" to 1/2" | 3" to 5" | 316 Stainless Steel |
| Sinsun Ceiling Grid (CEL) | Self-drilling or sharp point | Suspended ceilings, light fixtures | 1/4" | 2" to 4" | Zinc Carbon, 304 SS |
| Sinsun General Purpose (GEL) | Standard forged construction | Outdoor structures, fencing, tarps | 5/16" to 3/8" | 3" to 6" | 304 SS, Zinc Carbon |
| Engineered for critical structural applications where failure is not an option. Hot-forged construction eliminates the weak point found in bent-wire screw eyes. | |||||||||
| Catalog Number | Diameter | Length | Thread Length | Eye Inside Diameter | Shoulder | Material | Finish | Breaking Strength | Working Load (5:1) |
| HDE-1210 | 1/2" | 3-1/4" | 2.5" | 7/8" | Yes | High-Carbon Steel | Hot-Dip Galvanized | 11,000 lbs | 2,200 lbs |
| HDE-5812 | 5/8" | 4" | 3" | 1" | Yes | High-Carbon Steel | Hot-Dip Galvanized | 17,500 lbs | 3,500 lbs |
Key Features:
Hot-forged from single steel billet for continuous grain flow
Integrated shoulder for angular loads up to 45°
Cone point for easy starting and alignment
Hot-dip galvanized per ASTM A153 for corrosion resistance
Compatible with tree cabling hardware and heavy-duty thimbles
| 316 Stainless Steel: Maximum corrosion resistance for coastal and marine environments. Passivated finish provides additional protection against chloride attack. | |||||||||
| Catalog Number | Diameter | Length | Thread Length | Eye Inside ID | Shoulder | Material | Finish | Breaking Strength | Working Load (5:1) |
| SEL-1406 | 1/4" | 3" | 1.5" | 5/8" | No | 316 Stainless | Passivated | 2,500 lbs | 500 lbs |
| SEL-3808 | 3/8" | 4" | 2.25" | 3/4" | Optional | 316 Stainless | Passivated | 6,500 lbs | 1,300 lbs |
| SEL-1210 | 1/2" | 5" | 3" | 7/8" | Yes | 316 Stainless | Passivated | 11,000 lbs | 2,200 lbs |
| SEL-1210S | 1/2" | 3-1/4" | 2.5" | 7/8" | Yes | 316 Stainless | Passivated | 11,000 lbs | 2,200 lbs |
Key Features:
316 stainless steel with molybdenum for saltwater resistance
5,000+ hours salt spray resistance per ASTM B117
Compatible with ACQ pressure-treated lumber
Sharp, deep threads for easy entry into hardwoods
Non-magnetic (slightly magnetic after cold working)
| Acoustical Ceiling Fasteners: Specialized fasteners for suspended acoustical ceiling installations. Available in self-drilling variants for metal studs and sharp-point for wood joists. | ||||||||
| Catalog Number | Diameter | Length | Point Type | Eye Inside ID | Material | Finish | Working Load | Standards Met |
| CEL-2402SD | 1/4" | 2" | #3 Self-Drilling | 5/16" | High-Carbon Steel | Zinc Plated | 150 lbs | ASTM A510 |
| CEL-2403SD | 1/4" | 3" | #3 Self-Drilling | 5/16" | High-Carbon Steel | Zinc Plated | 150 lbs | ASTM A510 |
| CEL-2403 | 1/4" | 3" | Sharp (Gimlet) | 5/16" | High-Carbon Steel | Zinc Plated | 150 lbs | ASTM A510 |
| CEL-2404 | 1/4" | 4" | Sharp (Gimlet) | 5/16" | High-Carbon Steel | Zinc Plated | 150 lbs | ASTM A510 |
| CEL-2403SS | 1/4" | 3" | Sharp (Gimlet) | 5/16" | 304 Stainless | Plain | 150 lbs | ASTM F1941 |
Key Features:
Coarse threads for secure grip in ceiling applications
Self-drilling point (#3) pierces light-gauge metal studs quickly
Eye lag head designed for easy acoustical ceiling wire threading
Maximum installation speed: 2,500 RPM
Minimum penetration: Three full threads beyond metal structure
| Versatile fasteners for outdoor structures, fencing, shade sails, and general tensioning applications. | ||||||||
| Catalog Number | Diameter | Length | Thread Length | Eye Inside Diameter | Shoulder | Material | Finish | Working Load |
| GEL-3105 | 5/16" | 3" | 1.75" | 1/2" | No | Carbon Steel | Zinc Plated | 400 lbs |
| GEL-3107 | 5/16" | 4" | 2.25" | 1/2" | No | Carbon Steel | Zinc Plated | 400 lbs |
| GEL-3806 | 3/8" | 3" | 2" | 5/8" | No | Carbon Steel | Zinc Plated | 600 lbs |
| GEL-3808 | 3/8" | 4" | 2.5" | 5/8" | Optional | 304 Stainless | Plain | 600 lbs |
| GEL-3810 | 3/8" | 5" | 3" | 5/8" | Optional | 304 Stainless | Plain | 600 lbs |
| GEL-3812 | 3/8" | 6" | 3.5" | 5/8" | Optional | 304 Stainless | Plain | 600 lbs |
Key Features:
Rolled threads for consistent quality
Sharp gimlet point bites into wood quickly
Multiple material options for various environments
Suitable for standard wood anchors and shields
View sorted dimensional ranges, matched raw locked steady graded fit pressed bearing built outdoor indoor aligned tested core strength coated common timber fixed eye lag baseline mechanical folded use grade flow.
Get product| Nominal Diameter | Threads Per Inch (TPI) | Thread Major Diameter | Thread Root Diameter | Head/Eye Width | Eye Inside Diameter | Minimum Shoulder Diameter (if applicable) |
| 1/4" | 10 | 0.250" | 0.185" | 0.625" | 0.312" - 0.625" | N/A |
| 5/16" | 9 | 0.312" | 0.240" | 0.750" | 0.375" - 0.500" | N/A |
| 3/8" | 8 | 0.375" | 0.294" | 0.875" | 0.500" - 0.750" | 0.500" |
| 1/2" | 7 | 0.500" | 0.400" | 1.125" | 0.750" - 0.875" | 0.625" |
| 5/8" | 6 | 0.625" | 0.515" | 1.375" | 0.875" - 1.000" | 0.750" |
All dimensions in inches. Tolerances per ASME B18.2.1.
| Material Grade | Tensile Strength (min) | Yield Strength (min) | Hardness (HRC) | Corrosion Resistance | Standards |
| High-Carbon Steel (HDE Series) | 515 MPa (75,000 psi) | 415 MPa (60,000 psi) | 22-32 | Low (requires coating) | ASTM F1575 |
| 316 Stainless Steel (SEL Series) | 515 MPa (75,000 psi) | 205 MPa (30,000 psi) | 15-25 | Excellent (5,000+ hrs salt spray) | ASTM F1575, ISO 3506 |
| 304 Stainless Steel (CEL/GEL Series) | 515 MPa (75,000 psi) | 205 MPa (30,000 psi) | 15-25 | Good (1,500+ hrs salt spray) | ASTM F1575, ISO 3506 |
| High-Carbon Steel (CEL Series) | 450 MPa (65,000 psi) | 350 MPa (50,000 psi) | 20-30 | Low (zinc coating) | ASTM A510 |
| Finish Type | Applicable Series | Specification | Corrosion Resistance | Typical Thickness | Appearance |
| Hot-Dip Galvanized | HDE | ASTM A153 Class C | 500+ hours salt spray | 2.0-3.5 mils | Matte gray, uniform coating |
| Zinc Plated (Clear) | CEL, GEL | ASTM F1941 | 72-96 hours salt spray | 0.1-0.3 mils | Bright silver |
| Passivated 316/304 | SEL, GEL-SS | ASTM A967 | Base material dependent | N/A | Clean, oxide-free surface |
| Plain (Uncoated) | CEL-SS | N/A | Base material dependent | N/A | Natural stainless |
| Lag Diameter | Softwood Pilot Hole | Hardwood Pilot Hole | Drill Bit Size (Softwood) | Drill Bit Size (Hardwood) |
| 1/4" | 3/16" (4.8mm) | 13/64" (5.2mm) | #12 | #7 |
| 5/16" | 15/64" (6.0mm) | 1/4" (6.4mm) | #7 | 1/4" |
| 3/8" | 9/32" (7.1mm) | 5/16" (8.0mm) | 9/32" | 5/16" |
| 1/2" | 3/8" (9.5mm) | 13/32" (10.3mm) | 3/8" | 13/32" |
| 5/8" | 1/2" (12.7mm) | 17/32" (13.5mm) | 1/2" | 17/32" |
Rule:Pilot hole diameter = 70-75% of thread major diameter. Depth = Full thread length + 1/4".
| Diameter | Maximum Recommended Torque | Softwood Torque Range | Hardwood Torque Range | Installation Tool |
| 1/4" | 35 ft-lbs | 15-25 ft-lbs | 20-30 ft-lbs | Eye lag driver bit or socket |
| 5/16" | 55 ft-lbs | 25-35 ft-lbs | 30-45 ft-lbs | Socket adapter |
| 3/8" | 75 ft-lbs | 35-50 ft-lbs | 45-65 ft-lbs | Socket wrench |
| 1/2" | 120 ft-lbs | 60-85 ft-lbs | 80-110 ft-lbs | Torque wrench recommended |
| 5/8" | 180 ft-lbs | 90-130 ft-lbs | 120-160 ft-lbs | Torque wrench required |
Note:For ceiling grid installations (CEL series), maximum drive speed is 2,500 RPM. Do not over-torque as it can cause head snapping or thread stripping.
| Standard | Title | Applicable Series | Requirement |
| ASTM F1575 | Standard Test Method for Determining Bending Yield Moment of Lag Screws | HDE, SEL | Bending strength verification |
| ASTM A153 | Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware | HDE | Galvanizing quality |
| ASTM A510 | Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Carbon Steel | CEL | Carbon steel manufacturing |
| F.I.P.3-1000.7 | Fastener Industry Practice for Torsional Strength and Drill Speed | CEL | Torsional strength and drill speed |
| ASTM F1941 | Standard Specification for Electrodeposited Coatings on Mechanical Fasteners | CEL, GEL | Corrosion resistance |
| ISO 3506 | Mechanical properties of corrosion-resistant stainless steel fasteners | SEL, GEL-SS | Stainless steel properties |
| ASME B18.2.1 | Square and Hex Bolts and Screws | All | Thread dimensions |
| ANSI A300 | Tree Care Operations | HDE | Tree cabling applications |
| Series | Standard Package | Bulk Package | Master Carton | Pallet Quantity |
| HDE Series | 10 pieces per box | 100 pieces per carton | 10 boxes per carton | 40 cartons |
| SEL Series | 10 pieces per box | 100 pieces per carton | 10 boxes per carton | 40 cartons |
| CEL Series | 100 pieces per box | 1,000 pieces per carton | 10 boxes per carton | 36 cartons |
| GEL Series | 25 pieces per box | 250 pieces per carton | 10 boxes per carton | 40 cartons |
| Series | Manufacturing Location | Material Sourcing | Quality Certification |
| HDE Series | ISO 9001 certified facility | Domestic/US | 100% batch tested |
| SEL Series | ISO 9001 certified facility | Imported/Verified | 100% batch tested |
| CEL Series | ISO 9001 certified facility | Multiple origins | Sample tested per lot |
Technical Notes
Breaking Strength vs. Working Load: All Sinsun eye lag screws have a minimum design factor of 5:1, which means that the breaking strength divided by 5 is the recommended working load limit.
Angular Loading: Only the shouldered models (HDE series, SEL-1210S) can handle loads up to 45° off vertical. Models without shoulder can only be used for straight pull (0°).
Condition of the wood: The load ratings are based on the wood being sound, dry, and free of defects, rot, or decay. If the wood is green or wet, cut the work in half.
Temperature Limits: Stainless steel grades have properties between -200°F and 800°F. Carbon steel grades retain their properties between -40°F and 400°F.
For critical applications (overhead, dynamic loads), check for corrosion, bending, or thread damage once a year. If you find any problems are found, replace them right away.
Primary Applications: Where Sinsun Eye Lags Excel
1. ANSI A300-compliant tree cabling and bracing
Arborists use eye lag screws to put in cable systems that hold up weak tree unions and heavy branches. Sinsun eye lags are made to handle the changing loads of ice and wind.
Setup: Put two eye lags in the main limbs and connect them with cable and thimbles.
Sinsun Sizes: 1/2" x 3-1/4" and 5/8" x 4" with a shoulder
Strength to Break: 11,000 lbs (1/2") to 17,500 lbs (5/8")
Protection from corrosion: Hot-dip galvanized according to ASTM A153 for durability below the canopy
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2. Grids for ceilings that hang down
Commercial acoustic ceilings are hung from eye lag screws that are driven into metal studs or wood joists. Sinsun has both regular and self-drilling options.
Use: The eye holds up the ceiling grid by hanging wire.
The sizes of sinsun are 1/4" wide and 2" to 5" long.
Features: Coarse threads to hold wood and a #3 self-drill point for metal studs
Finish: Use zinc-plated or stainless steel in plenum areas.
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3. Anchoring at sea and at the dock
Make sure that cleats, fenders, and lifting points are securely attached to wooden docks and piers. 316 stainless steel is needed for things that will be in saltwater.
Use: attaching a mooring line or anchoring equipment
Sinsun Sizes: 5/16" to 1/2" in diameter
316 stainless steel with a passivated finish is the material.
Load Rating: 190 lbs to 2,200 lbs of working load, depending on size
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4. Rigging for construction and industry
Temporary anchoring for hoists, fall protection, or guy wires. Always check the load ratings and installation before using.
Use: Lifting equipment and temporary bracing
Sizes of sinsun: 3/8" to 5/8" in diameter
Material: high-carbon steel that has been forged and hot-dip galvanized
Safety Factor: 5:1 design factor (breaking strength 梅 5 = working load)
5. Structures and tensioning outside
Attach shade sails, tarps, and fencing to wood posts and beams.
Use: Tensioned fabric structures and vineyard trellising
Sinsun Sizes: 3/8" to 5/16" in diameter
304 stainless steel for general outdoor use and 316 for coastal use
Feature: Shouldered design can handle angled loads up to 45°.
01
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Q: What's the difference between an eye bolt and an eye lag?
A: Eye bolts have machine threads and require a nut on the opposite side. Eye lags have wood threads and screw directly into wood without a nut .
02
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Q: Can I use eye lags in concrete or masonry?
A: No. Eye lags are designed for wood only. For concrete, use expansion anchors or epoxy with machine-threaded eye bolts .
03
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Q: How do I remove an eye lag screw?
A: Insert a pry bar through the eye for leverage, or use an eye lag driver bit with a wrench. Turn counter-clockwise. If seized, apply penetrating oil and tap gently.
04
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Q: What size eye lag do I need for tree cabling?
A: For most tree cabling, use 1/2" diameter minimum. Sinsun HDE-1210 (1/2" x 3-1/4") is the industry standard for medium trees. For large trees or heavy limbs, use 5/8" .
05 /
Q: Are Sinsun eye lags rated for overhead lifting?
A: Sinsun provides breaking strength data, but overhead lifting applications require engineered systems designed by a qualified professional. Never suspend loads over people without proper engineering.
06 /
Q: Do I need a washer with eye lags?
A: No. Eye lags seat directly in wood. Shouldered designs provide bearing surface. For non-shouldered in soft wood, a flat washer can prevent the eye from embedding.
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