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Grade 100 Alloy Chain
Page 180
Chain Inspection

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GENERAL INFORMATION
WORKING LOAD LIMIT
  
ATTACHMENTS
The "Working Load Limit" is the maximum load in pounds which should ever be applied to chain, when the chain is new or "in as new" condition, and when the load is uniformly applied in direct tension to a straight length of chain. Any attachments, such as hooks or links, should have a rated "Working Load Limit" at least equal to the chain with which it is used.
PROOF TEST
  
SPECIFICATIONS
The "Proof Test" is a term designating the tensile test applied to new chain for the sole purpose of detecting injurious defects in the material or manufacture. It is the load which the chain has withstood under a test in which the load has been applied in direct tension to a straight length of chain. ANSI/ASME B30.9 2003
Paragraph 9-1.6.1 "Prior to initial use, all new and repaired chain and components of an alloy steel chain sling, either individually or as an assembly, shall be proof tested by the sling manufacturer or qualified person."
CAUTION
 
Only Crosby Alloy chain, Spectrum 8® or Spectrum 10®, should be used for overhead lifting applications.

It must be recognized that certain factors in the usage of chain and attachments can be abusive and lessen the load that the chain or attachments can withstand. Some examples are twisting of the chain; disfigurement; deterioration by straining; usage, weathering and corrosion; rapid application of load or jerking, applying excessive loads; and sharp corners cutting action.

When using chain slings in choker applications, the working load limit must be reduced by 20%. The Crosby A-1338 cradle grab hook can be used without any reduction to the working load limit.

MINIMUM ULTIMATE LOAD

  
ENVIRONMENTAL EFFECTS
 
The "Minimum Ultimate Load" is the minimum load at which new chain will break when tested by applying direct tension to a straight length of chain at a uniform rate of speed in a testing machine.  

Excessive high or low temperatures or exposure to chemically active environments such as acids or corrosive liquids or fumes can reduce the performance of the chain.
TEMPERATURE

Extreme temperatures will reduce the performance of alloy steel chain slings. Normal Operating temperature is -40 F to 400 F (-40 C to 204 C). See the temperature exposure chart below to determine reduction of WLL due to operating at, and exposure to elevated temperatures (see Table 2). Chemically Active Environments can have detrimental effects on the performance of chain. The effects can be both visible loss of material and undetectable material degradation causing significant loss of strength.

Usage exposure - Exposure to chemically active environments such as acids or corrosive liquids or fumes can reduce the performance of the chain. Special surface coating / plating / galvanizing: chain should not be subjected to galvanizing or any plating processes. If it is suspected that the chain has been exposed to chemically active environment, remove from service.

 

TABLE 2
Use of Crosby Grade 100 Chain Under Heat Conditions

Temperature
of
Chain

Reduction of Working Load Limit WHILE AT Temperature*

 Reduction of Working Load Limit  AFTER EXPOSURE to Temperature**
(ºF) (ºC)

Below
400

 Below
204

None

 None
400 204 10% None

500

 260

15%

 None
600 316 20% 5%

700

 371

30%

 10%

800

 427

40%

 15%

900

 482

50%

 20%

1000

 538

60%

 25%

Over
1000

 Over
538

    OSHA 1910.184 requires all slings exposed to temperatures over 1000º F to be removed from service.
* Crosby does not recommend the use of Alloy Chain at
temperatures above 800°F.
**When chain is used at room temperature after being heated
to temperatures shown in the first column.
__________________________________________________________________________________
CHAIN INSPECTION
  
TABLE 1
MAXIMUM ALLOWABLE WEAR AT ANY POINT OF LINK
Normal Chain or Coupling Link
Cross Section
Maximum Allowable Wear
Diameter (in.)
9/32
.037
3/8
.052
1/2
.069
5/8
.084
3/4
.105
7/8
.116
1
.137
1 1/4
.169
REFER TO ANSI B30.9

INSPECTION, REMOVAL AND REPAIR PROCEDURES PER ANSI B30.9

Refer to ASME B30.9-1.9 for further information.

Initial Inspection
Prior to use, all new, altered, modified, or repaired sling shall be inspected by a designated person to verify compliance with the applicable provisions of ASME B30.9-1.

Frequent Inspection
(a) A visual inspection for damage shall be performed by the user or designated person each day the sling is used.
(b) Conditions such as those listed in ASME B30.9-1.9.4 Removal Criteria, or any other condition that may result in a hazard shall cause the sling to be removed from service. Slings shall not be returned to service until approved by a qualified person.
(c) Written records are not required for frequent inspections.

Periodic Inspection
(a) A complete inspection for damage of sling shall be periodically performed by a designated person. Each link and component shall be examined individually; taking care to expose and examine all surfaces including the inner link surface. The sling shall be examined for conditions such as those listed in ASME B30.9-1.94 Removal Criteria, and a determination made as to whether they constitute a hazard.
(b) Periodic Inspection Frequency. Periodic inspection intervals shall not exceed one year. The frequency of periodic inspections should be based on:
(1) frequency of sling use
(2) severity of service conditions
(3) nature of lifts being made
(4) experience gained on the service life of slings used in similar circumstances.

Guidelines for the interval are:
Normal Service - yearly
Severe service - monthly to quarterly
Special Service - as recommended by a qualified person
(c) Written records of the most recent periodic inspection shall be maintained, and shall include the condition of the sling.

Removal Criteria
An alloy sling chain shall be removed from service if conditions such as the following are present:
(a) missing or illegible sling identification
(b) cracks or breaks.
(c) excessive wear, nicks or gouges. Minimum thickness on chain link shall not be below the values listed in Table 1.
(d) stretched chain links or components.
(e) bent, twisted, or deformed chain links or components.
(f) evidence of heat damage.
(g) excessive pitting or corrosion.
(h) lack of ability of chain or components to hinge (articulate) freely.
(i) weld splatter.
(j) for hooks, removal criteria as stated in ASME B30.10.
(k) other conditions, including visible damage, that cause doubt as to the continued use of the sling.

Repair
(a) Slings shall be repaired only by the sling manufacturer or a qualified person.
(b) A repaired sling shall be marked to identify the repairing agency per ASME B30.9 Section 9-1.7.
(c) Chain and components used for sling repair shall comply with the provisions of this ASME B30.9.
(d) Repair of hooks shall comply with ASME B30.10.
(e) Cracked, broken or bent chain links or components other than hooks shall not be repaired; they shall be replaced.
(f) Mechanical coupling links shall not be used within the body of an alloy chain sling to connect two pieces of chain.
(g) Modifications or alterations to the sling or components shall be considered as repairs and shall conform to all other provisions of this ASME B30.9.
(h) All repairs shall comply with the proof test requirements of ASME B30.9 Section 9-1.6.
 

 
 
 
 
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