Key Features
- Marine-grade construction: available in corrosion-resistant stainless steel, galvanized steel, or polished brass
- Precision-rolled sheave for smooth halyard operation and reduced line wear
- Heavy-duty swivel shackle or snap hook for secure attachment to mast, deck, or flagpole
- Sealed bearings (optional) to prevent water ingress and ensure long service life
- High working load limits – suitable for flags of all sizes, including storm flags
- Compact and lightweight design for easy installation and low windage
- Meets ship chandler quality standards for commercial and recreational use
Technical Specifications
| Specification | Details |
|---|---|
| Type | Single flag block / halyard pulley |
| Material | Stainless steel (316L), galvanized steel, or brass (selectable) |
| Sheave Diameter | 20 mm – 80 mm (0.8" – 3.1") depending on model |
| Line Diameter (Max) | 6 mm – 14 mm (1/4" – 9/16") |
| Attachment Type | Swivel shackle, snap hook, or eye |
| Working Load Limit | 150 kg – 800 kg (330 – 1760 lbs) |
| Breaking Load | 300 kg – 1600 kg (660 – 3520 lbs) |
| Bearing | Bronze bushing or stainless ball bearings (optional) |
| Finish | Polished, anodized, or epoxy-coated |
| Compliance | IMPA 371586 – Nautical Equipment |
Frequently Asked Questions
What are flag blocks used for on ships?
Flag blocks, also known as halyard pulleys, are used to route the flag halyard (rope) from the flag to the mast or deck, allowing the flag to be raised and lowered smoothly with reduced friction.
What material should I choose for a marine flag block?
For saltwater use, stainless steel (316L) is the best choice for maximum corrosion resistance. For budget-friendly options, galvanized steel is reliable, while brass offers a traditional look on classic yachts but requires more maintenance.
How do I choose the right size flag block?
Match the sheave diameter to your halyard diameter – the groove must be slightly larger than the line. Also consider the flag size and wind loads; larger flags require heavier-duty blocks with higher working load limits.
Do these flag blocks come with mounting hardware?
Yes, each block includes a mounting attachment (shackle, snap hook, or eye) as specified in the product configuration. Additional mounting accessories can be supplied separately from our ship store.
Inquire About This Product
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