LIFTINGSAFETY

Crosby Hooks information

DESIGN

The theoretical reserve capability of a hoist hook should be a minimum of 5 to 1 for carbon eye hooks, alloy eye hooks and carbon shank hooks and 4.5 to 1 for alloy shank hooks. Known as the DESIGN FACTOR, it is usually computed by dividing the catalog ultimate load by the working load limit. The ultimate load is the average load or force at which the product fails or no longer supports the load. The working load limit is the maximum mass or force which the product is authorized to support in general service. The design factor is generally expressed as a ratio such as 5 to 1. Also important to the design of hooks is the selection of proper steel.

COMPETITION CROSBY

Ask: What is the design factor? Ask: Is each production lot performance tested?

Crosby hoist hooks meet the design factor requirements of 5 to 1 for all carbon hooks, 5 to 1 for all alloy eye and swivel hooks and 4.5 to 1 for alloy shank hooks. Crosby’s QC 1400 program determines the mechanical properties of each manufacturing lot of hoist hooks. In addition to the heat treat process, Crosby hooks are designed with a cross section that, when overloaded, allows uniform deformation and straightening before ultimate failure.

QUENCHED AND TEMPERED

Quenching and tempering assures the uniformity of performance and maximizes the properties of the steel. This means that each hook meets its rated strength and other properties. This quenching and tempering process develops a tough material that reduces the risk of a brittle, catastrophic failure, thus improving impact and fatigue properties. As a result, if overloaded, the hook will deform before ultimate failure occurs, thus giving warn-ing. The requirements of your job demand this reliability and consistency. Quench and Tempering insures that not only is the working load limit met, but that ductility, fatigue and impact properties are appropriate.

Ask: Are their hooks quenched and tempered? Ask: If overloaded, do their hooks deform, giving warning before ultimate failure? Some competitors normalize the hooks, and as a result, desired properties are not achieved. A few even provide hooks in an “as forged” condition, which can result in brittle failure.

Crosby hoist hooks are quenched and tempered. This heat treatment process assures a hook that will deform prior to ultimate failure. Impact and fatigue properties are superior with quenched and tempered hooks. Crosby’s Quenched and Tempered carbon and alloy hoist hooks are recommended for all critical applications, including overhead lifting.

FULL LINE AND IDENTIFICATION

The proper application of hoist hooks requires that the correct type, size, and working load capacity of hook be used. All hooks must be load rated (with either the working load or a cross reference code). In addition the traceability code, size, and manufacturer’s name should be boldly marked on the product. Availability of a full line of eye, shank, and swivel hooks in carbon and alloy steel is essential when selecting the desired hook for the proper application.

Ask: Do they have a traceability system? Ask: Does their traceablity system tie into a comprehensive material testing program? Ask: Does their product offering cover the full range? Most competitors do not have the full line of hooks that Crosby produces. Most do not have a traceability system.

Crosby forges “Crosby” or “CG,” the Product Identification Code (P.I.C.), and working load limit (or working load cross reference code) into its full line. Crosby’s traceability system and P.I.C. are an integral part of the QC 1400 program.

APPLICATION INFORMATION

Detailed application information will assist you in the proper selection and use of hoist hooks. This information is most effective when provided in supporting brochures and engineering information. A formal application and warning system that attracts the attention of the user, clearly informs the user of the factors involved in the task, and informs the user of the proper application procedures is needed.

Ask: Do they provide hook application and warning information attached directly to the hook? Ask: What training support is provided? Most competitors do not have a comparable product warnings system and application information for hoist hooks.

The Crosby Product Warnings System provides detailed application and warning information for hoist hooks. In addition, a video on hook maintenance is also available. Field inspection criteria and repair instructions are also available. Training seminars conducted by Crosby provide training on the proper use of hoist hooks. Crosby training packets, supplied free to attendees of Crosby’s seminars, provide training materials needed to explain the proper use of hoist hooks.

All information above refers to Crosby General Catalogue 2009 Page 90, and previously to Crosby General Catalogue 2006 Page 86.

Crosby Value Added

  • U.S. ratings: When comparing to other hooks which are rated in short tons, the design factor of Crosby hooks (in short tons) is 5 to 1 for all carbon hooks, 5 to 1 for alloy eye and swivel hooks, 4.5 to 1 for alloy shank hooks and 4 to 1 for all bronze hooks.
  • Application information: Application and warning information is available for Crosby hoist hooks. The Crosby Warning System is designed to attract the attention of the user, clearly inform the user of the factors involved in the task, and provide the user with proper application procedures. Each Crosby hoist hook is tagged with appropriate application and warning information, thus insuring that the information is available at the point of application.
  • Charpy impact properties: Crosby’s quenched and tempered hooks have enhanced impact properties for greater toughness at all temperatures. Crosby can provide typical Charpy impact properties on selected sizes upon special request at the time of order.
  • Fatigue properties: Typical fatigue properties are available for selected sizes. In addition, these properties will be provided upon special request for other sizes. Crosby is in the process of fatigue rating hoist hooks to 20,000 cycles at 1-1/2 times the Working Load Limit.
  • Ductility properties: Crosby’s QC 1400 program provides results of actual test values for ductility of the material. These results are measured by reduction of area and elongation. This is done for each production lot and is traceable by the Product Identification Code (PIC).
  • Tensile strengths: Crosby’s QC 1400 program provides hardness, tensile, and yield strength for each production lot of hoist hooks. They are traceable by the Product Identification Code (PIC).
  • Material Analysis: Crosby can provide certified material (mill) analysis for each production lot, traceable by the Product Identification Code (PIC). Crosby, through its own laboratory, verifies the analysis of each heat of steel. Crosby purchases only special bar forging quality steel with specific cleanliness requirements and guaranteed hardenability.
  • Field inspection: Written instructions for visual, magnaflux, and dye penetrant inspection of hooks are available from Crosby. In addition, acceptance criteria and repair procedures for hooks are available.
  • Proof testing: If requested at the time of order, hooks can be furnished proof tested with certification. All SHUR-LOC® hooks (clevis and eye styles) are 100% proof tested with certificates.
  • Mag Certification: If requested at the time of order, hooks can be Mag inspected with certification.
  • World Class Certification: Certification to World Class Standards can be furnished upon request at the time of order. Specific standards include American Bureau of Shipping, Lloyds Register of Shipping, Det Norske Veritas, American Petroleum Institute, RINA, Nuclear Regulatory Commission, and other world wide standards.
  • Bronze Hooks: Crosby provides bronze shank hooks for non-sparking applications.
  • QUIC-CHECK®: Hoist hooks incorporate markings forged into the product which address two (2) QUIC-CHECK® features: Deformation Indicators: Two strategically placed marks, one just below the shank or eye and the other on the hook tip, which allows for a QUIC-CHECK® measurement to determine if the throat opening has changed, thus indicating abuse or overload. Angle Indicators: Indicates the maximum included angle which is allowed between two (2) sling legs in the hook. These indicators also provide the opportunity to approximate other included angles between two sling legs.

All information above refers to Crosby General Catalogue 2009 Page 91, and previously to Crosby General Catalogue 2006 Page 87.


Last updated: 21-07-2012 16:12:28

LiftingSafety uses cookies to improve your user experience,
To accept this, please click the 'accept' button below.

Top