33 COMMONWEALTH OF PENNSYLVANIA) COUNTY OP ALLEGHENY ) It Linda 0.

CONFIDENTIAL Approved Fellow.

Guide, 1934 An Instrument of Service prepared for the Profession-- and Containing ' reference data . on the design and specification of heating and ventilating systems-- Based on the Transactions--the Investigations of the Research Laboratory and Cooperating Institutions-- and the Practice of the Members and Friends oV The . ' Society ' ' TOGETHER WITH A Manufacturers' Catalog Data Section Containing Essential and Reliable Information-Concerning Modern Equipment - also The Roll of Membership of the Society' with ' *.

ROYD R.

Ropes, Chains, and Slings cold-working of the metal Wrought iron chain (commonly called iron crane or dredge chain) used to be the ac cepted material for slings, hoists, cranes, power shovels, and marine purposes where human life or property would be endangered by failure However, since the introduction of alloy chain m 1933, the use of wrought iron has declined steadily and has nearly dis appeared Because of this lack of commercial importance, it is not considered here Heat-treated carbon steel is sometimes used for sling chains It has high strength, high impact resistance, and good abrasion resistance Special purpose alloy chains are made from stainless steel, monel metal, bronze, and other materials They are designed for use where resistance to corrosive substances is required, or where their other special proper ties are desirable Proof coil chain (also known as common or hardware chain) is used for miscellaneous purposes where failure of the chain would not endanger human life or result m senous damage to property or equipment Proof coil chain should never be used for slings Properties of alloy chain Alloy chain is produced from heat-treatable alloy steel in conformance with ASTM spe cifications A391-58 Types and amounts of the alloying elements may vary according to requirements of die individual chain manu facturer Chain after heat treatment has typical mechanical properties as follows Tensile Strength Elongation 125,000 psi minimum 15 per cent minimum Table 23-] shows the recommended work ing load limits, proof test loads, and the minimum breaking strengths of alloy steel chain The working load limit (safe load strength) is arrived at by dividing the breaking strength (ultimate strength) by a specified safety factor The values shown in Table 23-J represent the maximum loads that should ever be applied m direct tension to a length of alloy chain All alloy chain is proof-tested m direct tension under the proof test loads shown, pnor to final inspection and shipment The data for other types of chain may be obtained from TABLE 23-J WORKING LOAD LIMITS, PROOF TEST LOADS AND MINIMUM BREAKING LOADS FOR ALLOY STEEL CHAIN Nominal Size of chain (in ) Working Load limit (lb) Proof Test (lb) Minimum Break (lb) V. 3.250 6,500 10,000 Ve 6,600 13,200 19,000 V, 11.250 22,500 32,500 Ve 16,500 33,000 50,000 V, 23,000 46.000 69,500 7/e 28,750 57,500 93,500 1 38,750 77,500 122,000 1 Ve 44,500 89,000 143,000 IV. 57,500 115,000 180,000 1Ye 67,000 134,000 207,000 IV, 80,000 160,000 244,000 IV. 100,000 200,000 325,000 Source Specification for Alloy Cham, American Society for Testing and Materials, A-391-65 AUoy Steel Cham Specifications, No 3001, Natrona!

0 Jolms-Manville P.

WHEEL nuts(Cont

1932 TRANSACTIONS National Safety Council .

I Public Utilities Section I Officers 1935-36 General Chairman--Roy M.

SILVEU (Jubilee SflFGTV EOIICRESS CHICAGO OCTOBER 10-14 1938 NATIONAL SAFETY COUNCIL, inc. --* < Courrll Inr ' l,, ' ' t ** a 33- 280GG | Foreword THK Transactions of the Silver Jubilee Congress and Ex position of the National Safety Council, October 10-14, l'H8, are published in two volumes.

550 INDUSTRIAL HYGIENE AND OCCUPATIONAL MEDICINE appraisal of symptoms were noted.

1 and told you a few things and showed you a few Page 269 2 documents. 3 I can't help to think that it is done for a 4 reason.

1 you?

NEG.

NEG.