Hot Dip Galvanized | Square Curved Washer | IEEE C135.80 & CSA C83

Square Curved Washer HDG | Utility Pole Washer | CSA C83 | Yokelink

Maximum Bearing Surface for Utility Pole Construction. The Yokelink Square Curved Washer is a critical foundational component in wood poleline and crossarm assemblies. Designed to be used with machine bolts, double arming bolts, and square nuts, these washers provide a significantly larger bearing surface than standard round washers.

Preventing Wood Damage: When high torque is applied to overhead line fasteners, the concentrated pressure can crush the wood fibers of the utility pole or crossarm, leading to loose connections over time. Our oversized square flat washers effectively distribute this load across a wider area, preserving the structural integrity of the timber.

Manufactured from high-strength carbon steel, every washer is heavily Hot Dip Galvanized to ASTM A153 standards, ensuring decades of reliable, rust-free performance in severe outdoor and coastal environments. Fully compliant with IEEE C135.80 and CSA C83 requirements.

Key Features of Square Curved Washer :

Design: Large square profile for maximum load distribution on wood.

Application: Protects utility poles and crossarms from bolt crushing.

Material: Heavy-duty carbon steel.

Finish: Hot Dip Galvanized (HDG) for ultimate corrosion resistance.

Standards: Meets IEEE C135 and CSA C83 utility specifications.

Production Process of Square Curved Washer

Square curved washers are made from ASTM A36 carbon steel. The raw material is sheared and blanked to form the square shape. A central hole is then punched to the required size. The washers are deburred and surface-finished to ensure smooth edges and flatness. They are hot-dip galvanized in accordance with ASTM A153 for corrosion resistance. All production and inspection comply with IEEE C135.1 and IEEE C135.80 standards.

The Application of Square Curved Washer

 

 

Square curved washers are widely used in overhead transmission and distribution lines, pole fixtures, cross arms and fastening systems. They distribute load evenly, protect surfaces and increase stability. Made from ASTM A307 carbon steel and hot-dip galvanized per ASTM A153, they offer high strength and excellent corrosion resistance. Fully compliant with IEEE C135.1 and IEEE C135.80 standards, they ensure safe, reliable and long‑lasting performance in outdoor power line applications.

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Yokelink Product Quality Inspection Report

 

We provide comprehensive inspection services for machine bolts, including SGS test bolts and formal Production Part Inspect Report (PPIR). The SGS tests verify the bolts’ compliance with international standards like ASTM A307 and IEEE C135.80, covering mechanical properties and corrosion resistance. The PPIR details all inspection items, ensuring each machine bolt meets dimensional, performance and quality requirements, providing reliable quality assurance for overhead line and industrial applications.

 

Technical Specifications of Square Curved Nut

 

Square Flat Washer

Part No.	Size	Hole	For Bolt	Weight
		Inch(C)	Inch	Kg / Pcs
A13F10	2X2X1/8	9/16	1/2	0.057
A13F20	2X2X1/8	11/16	5/8	0.054
A13F30	2-1/4X2-1/4X3/16	11/16	5/8	0.110
A13F40	2-1/4X2-1/4X3/16	13/16	3/4	0.106
A13F50	2-1/2X2-1/2X3/16	13/16	3/4	0.138
A13F60	3X3X3/16	13/16	3/4	0.218
A13F70	3X3X1/4	13/16	3/4	0.271
A13F80	4X4X1/4	15/16	7/8	0.489
A13F90	4X4X1/2	1-1/8	1	0.982

 

Square Curved Washer

Part No.	Size	Hole	For Bolt	Weight
		Inch(C)	Inch	Kg / Pcs
A13C10	2X2X1/8	9/16	1/2	0.057
A13C20	2X2X1/8	11/16	5/8	0.054
A13C30	2-1/4X2-1/4X3/16	11/16	5/8	0.110
A13C40	2-1/4X2-1/4X3/16	13/16	3/4	0.106
A13C50	2-1/2X2-1/2X3/16	13/16	3/4	0.138
A13C60	3X3X3/16	13/16	3/4	0.218
A13C70	3X3X1/4	13/16	3/4	0.271
A13C80	4X4X1/4	15/16	7/8	0.489
A13C90	4X4X1/2	1-1/8	1	0.982

 

Cross Reference (Industry Equivalents):

 

Square Flat Washer

Size	Part No.	HUBBELL	MACLEAN
2X2X1/8	A13F10	6811	J1073
2X2X1/8	A13F20	6812	J1074
2-1/4X2-1/4X3/16	A13F30	6813	J1075
2-1/4X2-1/4X3/16	A13F40	6814	J1076
2-1/2X2-1/2X3/16	A13F50
3X3X3/16	A13F60	6816	J1078
3X3X1/4	A13F70	6817	J1079
4X4X1/4	A13F80	6819	J1082
4X4X1/2	A13F90		J1081

 

Square Curved Washer

Size	Part No.	HUBBELL	MACLEAN
2X2X1/8	A13C10
2X2X1/8	A13C20
2-1/4X2-1/4X3/16	A13C30		J6821
2-1/4X2-1/4X3/16	A13C40
2-1/2X2-1/2X3/16	A13C50
3X3X3/16	A13C60
3X3X1/4	A13C70	682212	J6823
4X4X1/4	A13C80		J6829
4X4X1/2	A13C90

(Note: Manufacturer part numbers are for reference only. Yokelink products are interchangeable based on IEEE standards.)

 

Frequently Asked Questions (FAQ)

Q1: Why use a square flat washer instead of a standard round washer on a utility pole?

A: Wood utility poles and crossarms require a much larger load distribution area than metal-to-metal connections. A square flat washer provides significantly more surface area than a standard round washer of the same hole size. This prevents the bolt head or nut from sinking into and crushing the wood fibers when high torque is applied, ensuring a long-lasting, tight connection.

Q2: Are the holes in Yokelink HDG square washers oversized?

A: Yes. The holes are punched slightly larger (typically 1/16" over the bolt size) to accommodate the thick, protective layer of zinc added during the Hot Dip Galvanizing (HDG) process. This ensures the washer slides smoothly over the galvanized bolt during field installation without binding.

Q3: Can these washers be used with double arming bolts?

A: Absolutely. In fact, four square flat washers are typically required for every double arming bolt installation (one behind each of the four square nuts) to protect the crossarms on both sides of the utility pole.

Value-Added Supply Chain Services

 

1. Blanket Order & Free Warehousing

Yokelink offers Blanket Order programs: Place an annual order to lock prices, we manufacture your total volume and hold stock in our facility free of charge. Split Shipments: Schedule partial shipments (e.g., monthly or quarterly) based on your project progress. You get the benefits of just-in-time delivery without the risk of shortages.

2. DDP Shipping (USA Duties Included)Landed Cost Certainty

We handle the complex logistics. Our DDP (Delivered Duty Paid) service covers sea freight, US Customs clearance, and Section 301 tariffs. The price we quote is the final price delivered to your door / Warehouse.

3. Free Sample Program

We offer Free Samples to qualified commercial buyers for testing and approval.

 

Reference Information:

 

For IEEE C135.1 technical details behind our specification, see Understanding IEEE C135.1 Standard

https://www.yokelink.com/blog/understanding-ieee-c135-1-standard-for-zinc-coated-steel-bolts-and-nuts-in-overhead-line-construction-32333.html

 

IEEE C135.1 vs. IEEE C135.80: Key Differences in Pole Line Fasteners

https://www.yokelink.com/news/ieee-c135-1-vs-ieee-c135-80-key-differences-in-pole-line-fasteners-353686.html

 

IEEE C135.1 Specification Download:

 

https://www.yokelink.com/news/ansi-c135-1-ieee-std-c135-1-specification-163053.html

 

How to Choose the Right Machine Bolt Under IEEE C135.1

https://www.yokelink.com/news/how-to-choose-the-right-machine-bolt-under-ieee-c135-1-353752.html