704 East Benson - Sioux Falls, SD 57104
PHONE 1-800-888-1612 - FAX (605) 335-8033 - EMAIL sales@dakotariggers.com

 


With our large inventory of alloy chain and components, we can ship most orders the same day. Our chain slings are tagged and sent with a certification stating all components meet the Grade 8 specification required by OSHA.

Alloy chain slings are often selected when operating under high temperatures or rugged conditions that would abrade or destroy other types of slings. They are flexible, durable and long lasting, ductile, easy to inspect, collapsible for convenient storage, and will adhere securely to the contours of a load. Although chain will show little or no stretch at rated capacity, it does have the ability to elongate up to 20% prior to failure. This elongation serves as a visual warning sign prompting users to remove the sling from service before injury or damage is sustained from a broken chain sling. Perhaps the most advantageous feature of a chain sling is its ability to be repaired. Nearly any damaged component discovered during an inspection can be repaired and restored to useful condition. During the repair process, slings will be refurbished, proof tested and recertified, offering an economical alternative to new chain sling replacements.

Chain slings used for overhead lifting applications must be manufactured from alloy steel. Alloy chain, commonly 8600 series alloy, is subjected to quality control techniques surpassing those applied to lower grades of chain and is designed, approved and specifically recommended for overhead lifting. Alloy steel chains possess the strength, chemical content and mechanical properties necessary to meet government and industry standards. These specifications prescribe minimum elongation values, minimum proof test values, recommended working load limits and minimum statistical breaking strengths. Alloy chain can be distinguished from other popular grades of welded chain through its hallmark, or identification code, which is embossed into chain links approximately every 12" to 18". Grade 80 (or System 8) is the most frequently used alloy chain. Do not use any chain sling for overhead lifting before verifying that it is constructed of alloy steel. Different "Types" of chain slings can be fabricated and are usually designated by a three character symbol, based upon the number of legs and types of components used in the assembly:


First Character (Basic Type of Construction):
S = Single leg sling
SB = Single basket
D = Double leg sling
DB = Double basket
T = Triple leg sling
SE = Single endless basket
Q = Quadruple leg sling
DE = Double endless basket
C = Single leg sling with master link at each end

Second Character (Type of Master Link or End Link):
O = Oblong master link (recommended for all assemblies)
P = Pear shaped master link (upon request only)

Third Character (Type of Hook):
S = Sling hook
G = Grab hook
F = Foundry hook

 
Chain slings can be manufactured using permanent, welded coupling links, or if preferred, mechanical coupling links for quicker "in the field" assemblies. Either way, the sling must have an attached identification tag providing the grade, size, reach, type of sling, working load limit at a specific angle of lift, and serial number. Relative to other types of slings, chain slings have the poorest strength/weight ratio, best abrasion and cut resistance, average elongation and shock resistance, best flexibility, and best resistance to high temperatures.

With names like Gunnebo , ACCO , Crosby , CM, Peerless, KWS, and Campbell, we have the quality products you depend on. Our complete chain program includes repairs, testing, inspections, and training seminars for our customers. Many customers send in their chains for us to inspect and repair. We can also arrange to come to your facility and do on-sight inspections if necessary.

Pin Shackle

A pin shackle is closed with a clevis pin . Primarily used above the deck, pin shackles used to be the most common shackle used aboard boats. Pin shackles can be inconvenient to work with at times because they are secured using something else, usually a cotter pin or seizing wire.

Threaded shackle

The pin is threaded and one leg of the shackle is tapped. The pin may be "captive", to prevent it from dropping loose. The threads may gall if over-tightened or have been corroding in the salt air, so a liberal coating of lanolin or a heavy grease is not out of place on any and all threads. A shackle key or metal marlinspike are useful tools for loosening a tight nut .

Mousing

For safety, it is common to mouse a threaded shackle that is going to be left done up for some time in anything like a critical application. This is done by passing a couple of turns of mousing wire through the hole provided for this purpose in the unthreaded end of the pin and around the body of the shackle's hoop.

Alternatively, some threaded shackles are provided with a hole through the threaded end of the pin beyond where it emerges from the threaded hole. A cotter pin or a couple of loops of mousing wire through this hole serves the same purpose and secures the shackle in a closed position.

In this context, 'mouse' and 'mousing' are often pronounced with a harder 's', like mouze and mouzing .

Galvanic corrosion

Note that when mousing, the introduction of any other metal into permanent, direct contact with a safety-critical shackle may seriously reduce its (or the other metal's) useful life, especially under water and more especially under sea water. Frequent wetting or immersion, followed by exposure to the air again, is absolutely the worst combination. This is particularly relevant to shackles that form part of permanent moorings and anchor cables. For this reason, specially alloyed mousing wire is available and should be exclusively used for this purpose at all times. The use of galvanised or stainless steel cotter pins can have similar drawbacks.

Snap Shackle

As the name implies, a snap shackle is a fast action fastener which can be implemented single handed. It uses a spring activated locking mechanism to close a hinged shackle, and can be unfastened under load. This is a potential safety hazard, but can also be extremely useful at times. The snap shackle is not as secure as any other form of shackle, but can come in handy for temporary uses or in situations which must be moved or replaced often, such as a sailor's harness tether or to attach spinnaker sheets .

D-Shackle

A narrow shackle shaped like a loop of chain, usually a pin or threaded pin closure. This is probably the most common shackle type, and most others are a variation on the theme. The small loop can take high loads primarily in line. Side and racking loads may twist or bend this shackle. Also referred to as a chain shackle.

Headboard Shackle

This longer version of a D-shackle is used to attach halyards to sails , especially sails fitted with a headboard such as on Bermuda rigged boats. Headboard shackles are often stamped from flat strap stainless steel, and feature an additional pin between the top of the loop and the bottom so the headboard does not chafe the spliced eye of the halyard.

Twist Shackle

A twist shackle is usually somewhat longer than the average, and features a 90° twist so the top of the loop is perpendicular to the pin. One of the uses for this shackle include attaching the jib halyard block to the mast , or the jib halyard to the sail, to reduce twist on the luff and allow the sail to set better.

Bow Shackle

With a larger "O" shape to the loop, this shackle can take loads from many directions without developing as much side load . However, the larger shape to the loop does reduce its overall strength. Also referred to as an anchor shackle.

Lifting Clamps

Let Dakota Riggers supply you with quality lifting clamps by Merrill, Renfroe, IP, and CM. We can also help you with repair-part needs and proof test your repaired clamp, if needed

 

 


 
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