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Welding and Cutting TABLE 31-B FILTER LENS SHADE NUMBERS FOR VARIOUS WELDING AND CUTTING OPERATIONS (WELDER AND HELPERS) Type of Operation Recommended Shade Number Resistance welding, and for protection against stray light from nearby welding and cutting (if persons are out of the danger zone) Clear or filters up to No 2 Torch brazing or soldering 3 to 4 Light oxygen cutting and gas welding (to '/a in ) 4 or 5 Oxygen cutting, medium gas welding (Vs to 'A in ) and arc welding up to 30 amps 5 or 6 Heavy gas welding (over '/* in) and arc welding and cutting from 30 to 75 amps 6 or 8 Arc welding and cutting from 75 to 200 amps 10 Arc welding and cutting from 200 to 400 amps 12 Arc welding and cutting exceeding 400 amps 14 NOTE Flash goggles should be worn under all arc welding helmets particularly for gas-shielded metal arc welding Adapted from Welding Handbook, 5th ed American Welding Society items should conform to ASI Standard Z2 1, Safety Code for Head, Eye, and Respiratory Protection Table 31-B is a guide for select ing the correct filter lens for various welding and cutting operations Goggles or spec tacles should have side shields Guidance for lens care is given in Chapter 38, "Personal Protective Equipment " Protective clothing Some of the items of protective clothing needed by welders (Fig 31-12) are 1 Flame-resistant gauntlet gloves, except on very light work 2 Aprons of leather, asbestos, or other flameresistant material to withstand radiated heat and sparks 3 For heavy work, fire-resistant leggings, high boots, or similar protection 4 Safety shoes, wherever heavy objects are handled Low-cut shoes with unprotected tops should not be used because of the spark hazard 5 For overhead work, capes or shoulder covers of leather or other suitable mate rial Skull caps of leather or flame-resistant fabric may be worn under helmets to prevent head bums Also, for overhead welding, ear protection (wool or rubber plugs or wire screen protectors) is some times desirable 6 Safety hats or other head protection against sharp or heavy falling objects Operators and other persons working with inert-gas shielded arc welding should keep all parts of the body which could be exposed to the ultraviolet and infrared radiation covered to protect against skin bums and other types of injuries Dark clothing, partic ularly a dark shirt, is preferable to lightcolored clothing in order to reduce reflection to the operator's face underneath the helmet Cotton clothing disintegrates m from one day to two weeks, presumably because of the high ultraviolet radiation from arc welding and cutting Wool or leather clothing, there fore, is preferable to cotton because it is more resistant to deterioration For gas-shielded arc welding, woolen cloth ing is also preferable to cotton It is not readily ignited and protects the welder from changes m temperature Cotton clothing, if used, should be chemically treated to reduce flammabilitv In either case, clothing should be thick enough to keep radiation from pene trating it Outer clothing should be reasonably free from oil and grease Sleeves and collars should be kept buttoned Aprons and overalls should have no pockets, in which sparks could be caught, on the front of them For the same reason, trousers or overalls should not have tumed-up cuffs 944