316 Stainless Steel Cable
316 Stainless Steel Cable is a 7 x 19-strand aircraft cable. Custom cut to specific boat lift lengths. It retains ductility over long periods while running over sheaves and offers moderate corrosion resistance.
Compounding is required for boats weighing over 6,000 lbs. Safety factor and rating systems are based on the ASME (American Society of Mechanical Engineers) recommendations. The same applies to overhead cranes.
- Used best in saltwater applications.
- Most commonly used cable for boat lifts.
- Do not rely on “Breaking Strength” when rating a cable.
The diameter of aircraft cable is determined by multiplying the number of wires in each strand by the number of strands. “7 x 19” means that there are seven 7 strands with each strand having 19 wires. This technology provides the most flexibility in aircraft cables.
In boat lift applications, BH-USA recommends 7×19 aircraft cables. Consider at least a 5:1 safety factor when calculating working loads. For boat lifts, use a minimum of 4 drops. Test certificates for all cables sold by BH-USA are available upon request.
It is not recommended to use 7 x 19 aircraft cable for aircraft controls. 7 x 19 aircraft cable should never be used for lifting humans.
Safe Working Load vs. Minimum Breaking Strength
When selecting wire rope, it is crucial to use the Safe Working Load (SWL) of the cable rather than the breaking strength. Breaking strength is just that, it’s the amount of force a newly woven wire rope can withstand under perfect conditions, where if you added one more pound, the rope would snap!
Why aren’t we using breaking strength?
Testing the breaking strength of wire rope was performed on a machine that isolates just the wire rope so that the end connections do not affect the breaking strength. As a system, wire ropes include the wire rope itself as well as the end connections that work together dynamically. Because they must bend around cables and sheaves, they can only be as strong as their weakest link. Minimum breaking strength refers to a wire rope’s maximum tension that it can sustain under ideal circumstances, without accounting for the other factors that compromise the system’s strength.
What is the reason behind the low rating?
The Safe Working Load includes a safety factor (SF) for all the things that can happen to wire rope during its useful life which may reduce its breaking strength. ASME recommends a safety factor for this type of equipment. This is so that the lift can still safely support the load if at least one or more factors working to break the wire rope are present. Wire ropes deteriorate over time, lowering their breaking strength as they lose their safety factor.
|Lift Size||1 Part Straight Line||2 Part Compounded|
|2,800 lbs.||3/16 in.||3/16 in.|
|4,500 lbs.||1/4 in.||3/16 in.|
|6,000 lbs.||5/16 in.||1/4 in.|
|9,000 lbs.||X||1/4 in.|
|10,000 lbs.||X||1/4 in.|
|13,000 lbs.||X||5/16 in.|
|16,000 lbs.||X||3/8 in.|
|24,000 lbs.||X||3/8 in.*|
In order to find out what size wire rope is required for your lift, you must first calculate the total weight to be lifted, including the “wet” weight of the boat, the maximum cargo that can be loaded into the boat, and the weight of the lifting cradle.
- Water (Ballast, live well, potable, etc.)
- Any cargo items in the boat (Note: There should never be people in the boat while being lifted.)
- Boat cradle and bunks
Typically, the weight specified by a boat manufacturer refers to its “dry” weight. In order to calculate the “wet” weight, you must include the fuel weight- (6.30 lb/US gal for gasoline and 6.94 for diesel), the water weight (8.34 lb/US gal) that may ever be present in the boat, and the estimated weight of possible cargo (i.e., coolers, skis, etc.).
|Cable Size||Cable Material||Lifting Capacity||Min. Breaking Strength||Safe Working Limit||Best Water Type|
|3/16 in.||Stainless||1,050 lbs. *||3,700 lbs.||925 lbs.||Saltwater|
|3/16 in.||Galvanized||925 lbs. *||4,200 lbs.||1,050 lbs.||Freshwater|
|1/4 in.||Stainless||1,750 lbs. *||6,400 lbs.||1,600 lbs.||Saltwater|
|1/4 in.||Galvanized||1,600 lbs. *||7,000 lbs.||1,750 lbs.||Freshwater|
|5/16 in.||Stainless||2,450 lbs. *||9,000 lbs.||2,250 lbs.||Saltwater|
|5/16 in.||Galvanized||2,250 lbs. *||9,800 lbs.||2,450 lbs.||Freshwater|
|3/8 in.||Stainless||3,600 lbs. *||12,000 lbs.||3,000 lbs.||Saltwater|
|3/8 in.||Galvanized||3,000 lbs. *||14,400 lbs.||3,600 lbs.||Freshwater|
* – For boat lift applications, use a minimum of four drops.
DO NOT LIFT HUMANS
Products cannot operate indefinitely at their rated capacity. The wire rope and cable must be regularly inspected for any deterioration that may result in loss of strength. It is the user’s responsibility to assess whether further usage of the rope will pose a safety hazard. Regularly lubricate operating ropes. Avoid getting under any raised loads and stay away from the force of any load.
AVOID SHOCK LOADS
Due to the unpredictable circumstances that occur after a purchase of this cable, BH-USA cannot warranty or be held responsible for the cable after the purchase date. A working load limit for each application must be determined by the ultimate user. There are many factors to consider, among them, but not limited to, the load applied, the speed of operation, the acceleration or deceleration, the length of the rope or cable, shock loads, abrasion, corrosion, the number, size, condition, and position of drums and sheaves, and the danger to life and property if a rope or cable breaks. The storage, use, maintenance, and lubrication of wire ropes and cables must comply with normal safety standards; and the equipment must be designed, maintained, and operated correctly. Conduct regular inspections.
Avoid kinking, knotting, or crushing. Never use wire rope made or sold by BH-USA to lift humans.
- Commercial-grade cable
- Size determined by the outer diameter
- Cut in-house at BH-USA
- Made from 316 Stainless Steel