Carriage Bolts
Carriage Bolts Overview
Carriage Bolts are round-head fasteners with a square neck that locks into the material to prevent rotation during tightening.
This design allows secure single-side installation while keeping the head surface smooth and clean for exposed applications.
How Carriage Bolts Work
The square neck locks into a square hole to prevent rotation during tightening.
This allows the nut to be secured from one side without holding the bolt head, improving assembly efficiency and installation stability.
Materials & Surface Finishing
Key-CNC supports multiple material options:
Carbon Steel – high strength structural use
Stainless Steel (304 / 316) – corrosion resistance
Alloy Steel – enhanced mechanical performance
Aluminum – lightweight assemblies
Surface treatments:
Zinc Plating
Black Oxide
Passivation
Hot-dip galvanizing
Common Types
Standard Carriage Bolts
General-purpose design for wood and metal fastening applications.
01
Short Neck Carriage Bolts
Designed for thinner materials where reduced neck height is required.
02
Long Neck Carriage Bolts
Provides deeper locking engagement for high-strength assemblies.
03
Stainless Steel Carriage Bolts
Used in corrosion-resistant environments such as outdoor or marine applications.
04
Manufacturing Process
Carriage Bolts are produced through controlled machining and forming processes:
- CNC heading for round head formation
- Precision forming of square neck structure
- Thread rolling for strength improvement
- Heat treatment (if required for alloy steel)
- Surface finishing and anti-corrosion treatment
- Full dimensional inspection before shipment
Installation Guide
Carriage Bolts require a properly shaped square or tight-fitting hole to ensure anti-rotation performance.
During installation:
- Insert from head side
- Ensure square neck fully engages material
- Tighten nut from opposite side
- Avoid oversized holes to maintain locking effect
Key-CNC applies strict inspection procedures:
Thread gauge inspection (GO / NO-GO)
Square neck dimensional verification
Head geometry inspection
CMM measurement
Coating thickness testing
Each batch is fully inspected before shipment.
FAQ
Q: What is the main advantage of Carriage Bolts?
A: They prevent rotation during tightening for secure single-side installation.
Q: Where are they commonly used?
A: In wood structures, steel frames, and industrial assemblies.
Q: Can they be used in metal sheets?
A: Yes, with a properly formed square hole for locking.
Q: Does Key-CNC support customization?
A: Yes, full OEM customization is available.
Hot Tags: carriage bolts, China carriage bolts manufacturers, suppliers, factory
