The Strongest Link in Your Chain
The strongest link – Mantus swivel is stronger than its corresponding Grade 40 chain. (WLL is 1/5 UBS)
Integrated shackle design completely eliminates side loading making this the safest swivel on the market.
The pin on the chain side of the swivel is the strength limiting part since the geometry of the chain determines the pin size. Mantus swivel is the first to feature an oblong pin to maximizes the pin strength, with the aid of computer modeling and physical testing we truly created a swivel that is the strongest link.
Note the innovative shackle bolt design – no shackle dog! This slim hex head design (with holes for safety wire) offers a slimmer profile making it easier for translating through your bow roller.
316 L Stainless Steel, Precision Cast and Electro-Polished
Swivels are available in three sizes : S1 – S2 – S3
|Imperial Mantus swivels fit all Imperial chain sizes||Imperial Chain||1/4 – 5/16||5/16 -3/8||3/8 -1/2|
|Universal Mantus swivels fit metric chain||Metric Chain||6mm – 8mm||8mm – 10 mm||11 mm – 13 mm|
|UBS (Ulitmate Breaking Strength)||11,000 lb/ 5 T||19,800 lb/ 9 T||35,000 lb/ 16 T|
|These numbers are used to generate the recommendations below||WLL (Working load limit) (Safety Factor 5)||2,200 lb/ 1T||3,960 lb / 1.8 T||7,000 lb / 3.2 T|
|Chain Size (in)||1/4||5/16||3/8||7/16||1/2|
|Recommended swivel model for a given chain type and size||Grade 30 Chain||S1||S1||S2||S3||S3|
|Grade 40 Chain(G4 HT)||S1||S1 or S2||S2 or S3||S3||S3|
|Grade 70 Chain||S1||S2||S3||S3||NA|
When sizing for 5/16 Grade 40 chain one has an option between S1 and S2 swivels: S1 is lightly undersized, it has the same breaking load as the chain and slightly lower WLL. For boats under 40 feet we recommend the S1 swivel and for boats over 40 feet we recommend the S2 swivel.
|Imperial Chain Type||G30 (Proofcoil/BBB) (lb) UBS / WLL / WLL inflated*||G40 HT (lb) UBS / WLL / WLL inflated*||G70 HT (lb) UBS / WLL / WLL inflated*|
|1/4||5,000 / 1,250||7750 / 1,938 / 2,600||9,450 / 2,350 / 3,150||UBS -Ultimate Breaking Strength (lb) WLL – Working Load Limit (lb) WLL Inflated* – Working Load Limit inflated using a a different safety factor than is standard. See note below.|
|5/16||7,600 / 1,900||11,600 / 2,900 /3,900||14100 / 3,500 / 4,700|
|3/8||10,600 / 2,650||16,200 / 4,100 / 5,400||19800 / 4,950 / 6,600|
|7/16||NA||21,600 / 5,400 / 7,200||26,250 / 6,560 / 8,750|
|1/2||18, 000/ 4,500||27,600 / 6,900 / 9,200||33,900 / 8,475 / 11,300|
|* Grade 40/70 chain types claim inflated working load limit values. Typically chains working load limit is calculated as 1/4th of the ultimate breaking strength. Published WLL for Grade 70 /Grade 40 chain are calculated using the safety factor of 3, or UBS/3 = WLL. (G4 HT) is only 50% stronger than G30 chain and Grade 70 chain is only 20% stronger than G40 chain and 85% stronger than G30 chain. Thus WLL values we use to size you with the correct swivel are WLL = UBS/4 regardless of the chain type . For Mantus Swivels, we use a safety factor of 5 when determining the WLL recommendations.|