Yokelink Carriage Bolts (also known as Round Head Square Neck Bolts) are universally used in pole line construction to securely attach crossarm braces to wooden crossarms.

The square neck under the smooth, round head is designed to bite into the timber. This self-locking feature prevents the bolt from turning when the nut is being tightened, allowing for fast, one-wrench installation by a single lineman. Manufactured from high-strength carbon steel and fully Hot Dip Galvanized (ASTM A153 Class C) to withstand severe weather conditions.

Carriage Bolt Key Features :

Head Style: Smooth round head prevents snagging.

Square Neck: Bites into wood crossarms to prevent rotation during assembly.

Application: The industry standard for mounting flat crossarm braces.

Finish: Premium HDG for extended service life in all environments.

Assembly: Includes one hex nut or square nut (as specified).

Dimenisons : Accordance with ANSI/ASME B18.5

Carriage Bolt Factory Production Process:

 

Yokelink Quality Control and Testing Equipments

 

We don't just reference standards; we also verify them in practice: each batch of products undergoes destructive tensile testing in our internal laboratory to ensure load performance exceeds the minimum requirements of IEEE C135.1 / IEEE C138.80 or CSA specification; we use optical comparators to ensure the geometric accuracy of chamfered tips and rolled threads, enabling convenient on-site installation; at the same time, we conduct comprehensive testing on Rockwell hardness, coating thickness, and other parameters, and each shipment is accompanied by the original manufacturer's material specifications (MTRs) and quality inspection reports, with all data traceable back to the raw material furnace number.

 

 

Key Application Scenarios of Carriage Bolt:

 

Carriage bolts are widely used in overhead power lines, wooden structures, and general engineering connections. They feature a smooth round head and square neck to prevent rotation during installation. Compliant with IEEE C135.1, IEEE C135.80 and made from ASTM A307 steel with hot-dip galvanized finish per ASTM A153, they provide secure, stable fastening for cross arms, poles, and outdoor components, ensuring strong corrosion resistance and reliable performance in long-term service.

 

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 Carriage Bolt

3/8 inch Diameter

Part No.	Size	Bolt Length	Thread Length	Weight
		Inch(A)	Inch(B)	Kg / Pcs
A0538-03	3/8"X3"	3	2	0.068
A0538-04	3/8"X4"	4	3	0.074
A0538-4.5	3/8"X4-1/2"	4-1/2	3	0.075
A0538-05	3/8"X5"	5	3	0.080
A0538-5.5	3/8"X5-1/2"	5-1/2	3	0.091
A0538-06	3/8"X6"	6	3	0.098

1/2 inch Diameter

Part No.	Size	Bolt Length	Thread Length	Weight
		Inch(A)	Inch(B)	Kg / Pcs
A0512-4.5	1/2"X4-1/2"	4-1/2	3	0.157
A0512-05	1/2"X5"	5	3	0.160
A0512-06	1/2"X6"	6	3	0.184
A0512-07	1/2"X7"	7	4	0.200
A0512-08	1/2"X8"	8	4	0.232

5/8 inch Diameter

Part No.	Size	Bolt Length	Thread Length	Weight
		Inch(A)	Inch(B)	Kg / Pcs
A0558-03	5/8"X3"	3	2-1/2	0.197
A0558-04	5/8"X4"	4	3	0.235
A0558-05	5/8"X5"	5	3	0.273
A0558-06	5/8"X6"	6	3	0.311
A0558-07	5/8"X7"	7	4	0.348
A0558-08	5/8"X8"	8	4	0.386

 

 

Cross Reference (Industry Equivalents):

 

3/8 inch Diameter

Size	Part No.	HUBBELL	MACLEAN
3/8"X3"	A0538-03
3/8"X4"	A0538-04	8634	J8634
3/8"X4-1/2"	A0538-4.5	863412	J8634-1/2
3/8"X5"	A0538-05	8635	J8635
3/8"X5-1/2"	A0538-5.5
3/8"X6"	A0538-06	8636	J8636

 

1/2 inch Diameter

Size	Part No.	HUBBELL	MACLEAN
1/2"X4-1/2"	A0512-4.5
1/2"X5"	A0512-05	8645	J8645
1/2"X6"	A0512-06	8646	J8646
1/2"X7"	A0512-07	8647	J8647
1/2"X8"	A0512-08		J8648

 

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

 

Frequently Asked Questions (FAQ)

 

1.Q:Can I use Yokelink poleline fasteners bolts to replace Hubbell or MacLean parts?

 

A: Yes. Our poleline hardware bolts are functionally equivalent and interchangeable with industry-standard part numbers such as the Hubbell 86xx series and MacLean J86xx series. They meet or exceed the same mechanical load ratings

 

2.Q: Do you provide Mill Test Reports (MTRs) ,Drawing, or Factory Inspection Reports?

 

A: Yes, transparency is our standard. Full Mill Test Reports, Galvanizing Certificates, and Factory Inspection Reports are available with every shipment upon request, traceable to the raw material heat number.

 

3.Q:Are your products suitable for harsh environments?

 

A:Yokelink machine bolts are specifically processed with Heavy-Duty Hot Dip Galvanizing (ASTM A153 Class C) to withstand the extreme heat, UV exposure, and high salinity conditions typical of the Middle East (KSA) region. Ideal for SEC (Saudi Electricity Company) distribution.

 

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

 

ASTM A153 vs IEEE C135.1: Hot-Dip Galvanizing Standards for Fasteners

https://www.yokelink.com/news/astm-a153-vs-ieee-c135-1-hot-dip-galvanizing-standards-for-fasteners-352002.html

 

IEEE C135.1 Specification Download:

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