aning process to avoid unnecessary f the protective film, particularly at of the aluminum sheet. Chromic acid inhibitive treatments tend to restore ilm.
severe cleaning is necessary with inr corrosion (attack along grain
s). The mechanical removal of all products and visible delaminated rs must be accomplished in order to the extent of the destruction and to he remaining structural strength of onent. Inspection with a 5- to 10- gnifying glass or the use of dye peneassist in determining if all unsound I corrosion products have been reinding to blend or fair out the edges ed areas can best be accomplished by minum oxide-impregnated rubberels. Chemically inhibit the exposed und restore chemical surface films or he same manner as for other alumiices.
esium is the most chemically active of s used in aircraft construction and is the most difficult to protect. The ad complete correction of the coating imperative if serious structural dambe avoided. Treat the corroded area ercent chromic acid solution to which added approximately 20 drops of batrolyte per gallon, in the same manaluminum alloys.
ROSION PROOFING OF LANDPLANES LANES. In the repair or alteration of use corrosion proofing materials the or equivalent to, that originally apss the repair or alteration would recreased susceptibility to corrosion, in e, employ additional corrosion protecures.
ROSION PROOFING OF LANDPLANES D TO SEAPLANES. A special problem tered in the conversion of landplanes es. In general, landplanes do not reosion proofing to the same extent as nes manufactured as such. Corro- Page 127 sion-proofing standards for landplanes converted to seaplanes are divided into two classes: (1) Necessary minimum precautions;
and (2) Recommended precautions. Regardless of such precautions, it is imperative that the exterior surfaces of seaplanes be washed with clear fresh water immediately following extended water operation, or at least once a day when operated in salty or brackish water. Wash interior surfaces of seaplanes exposed to spray, taking care to prevent damage to electrical circuits or other items subject to injury.
a. Necessary Minimum Precautions. The following procedures are considered the minimum to safeguard the airworthiness of the converted aircraft and are not in themselves intended to maintain airworthiness for an indefinite period.
(1) Unless already protected, treat exposed fittings or fittings which can be reached through inspection openings with two coats of zinc chromate primer, paralketone, nonwatersoluble heavy grease, or comparable materials.
This applies to items such as wing-root fitwing-strut fittings, control-surface hinges, horns, mating edges of fittings, and attach bolts, etc.
(2) Coat nonstainless control cables with grease or paralketone or other comparable protective coating, if not replaced with corrosion-resistant cables.
(3) Inspect all accessible sections of aircraft structure. Clean structural parts showing corrosion and refinish if corrosion attack is superficial. If a part is severely corroded, replace with an adequately corrosion-proofed part.
b. Recommended Precautions. The recommended precautions are those which are suggested as a means of maintaining such aircraft in condition for safe operation over extended periods of time.
(1) Provide additional inspection openings to assist in detecting corrosion. Experience has shown openings to allow inspection of lower and rearward portion of the fuselage to be particularly desirable.
(2) Incorporate additional provisions for free drainage and ventilation of all interiors to Par 250
Page 128 AC 43.1:
prevent collection of moisture (scoop type drain grommets).
(3) Protect the interior of structural steel tubing. This may be done by air and watertight sealing or by flushing with hot linseed oil and plugging the openings. Inspect tubing for missing sealing screws, presence of entrapped water.
local corrosion around sealing screws, welded clusters, and bolted fittings which may be indicative of entrapped moisture.
(4) Slit the fabric of fabric covered aircraft longitudinally on the bottom of the fuselage and tail structure for access to these sections. Cont teracts any advantages in their speec fectiveness. Ise materials which are neutral and easy to remove.
c. Removal of Spilled Battery Acid.
to neutralize spilled battery acid, us bicarbonate (baking soda). or sodiu (borax) 20 percent by weight dissolved After neutralization, remove alkali :
pletely with copious quantities of wate vent corrosion. An application of paint to the structure surrounding th may be an effective control for this tyl rosion.
the lower structural members with zine chromate primer (two coats) ; follow by a coat of dope proof paint or wrap with cellophane tape and rejoin the fabric. This precaution is advisable within a few nonths after start of operation as a seaplane.
(5) Spray the interior of metal-covered wings and fuselages with an adherent corrosion inhibitor.
(6) Place bags of potassium or sodium dichromate in the bottom of floats and boat hulls to inhibit corrosion.
* 254. HANDLING AND CARE OF AIRCRAF ERED FROM WATER IMMERSION. Aircr were recovered from partial or total i in water, including flash floods, have lowed to air dry, in certain instances.
safety precantions other than a cursor tion of the aircraft exterior. The la adequate cleanup of water-immersed a subsequently adversely affect the safet aircraft. That is, water immersion inc probability of corrosive attack, the re lubrication, the deterioration of airc
(7) Prevent the entry of water by sealing.
as completely as possible, all openings in wings, fuselage, control-surface members, openings for control cables, tail-wherl wells, ete.
253. CLEANERS, POLISHES, BRIGHTENERS, 11 iS important that aircraft be kept thoroughly clean terials, and/or degradation of electi avionic equipment.
Sea water, because of salt content, corrosive than surface fresh water.
fresh water may contain varying amou and, as drying occurs, the salt concen increased and corrosive attack accelerat of deposits containing contaminating substances such as oil, grease, dirt, and other foreign materials.
a. Materials. Avoid damage to aircraft by not using harmful cleaning, polishing, brightening, or paint-removing naterials. Use only those compounds whieh conform to existing government or established industry specifications or The most important factor following of an aircraft from sea or fresh water i is prompt action. Components of the which have been water immersed, suc poverplant, accessories, airframe section ing mechanisms, screws, bearings, worl faces, fuel and oil systens, wiring, ra radar should be disassembled. to the ex product- that have been specifically recommended by be a reraft manufacturer as being satisfactory for the intended application. Observe the product manufacturer's recommendations concerning de of his agent.
b. Cherical Cleaners. Chemical cleaners must be used with preat care in cleaning assembled sidered necessary, so that the contamir be completely removed.
a. Initial Fresh Water/Detergent Wc soon as possible after the aircraft is 1 from water immersion, thoroughly w taminated internal and external areas of craft using a water/detergent solution as aireraft. The danger of entrapping corrosive 01) Mix liquid detergent (MI- materials in faving surfaces and crevices cou- Type I) and isopropyl alcohol (TT-I Por 252
CHG T ight parts detergent to 20 parts of dd the detergent/alcohol mixture to tap water and mix thoroughly. For ne part of the foregoing concentrate ts of tap water (warm water if availnix thoroughly.
the above specified detergent/alcohol re not available, use water emulsion ›mpound (MIL-C-43613). Add one und to nine parts water. If the MIL ompound is not available, use any ild household detergent solution with 'ater.
Precautions. The following safety i should be observed:
ctrically ground the aircraft. Attach lead to the aircraft at a point which the area that could contain explosive the landing gear of land planes is
• supporting mechanism, install a ir, jury strut, landing gear downlocks itable devices to insure that the gear ollapse. If the landing gear is not insure that the aircraft is solidly to prevent hazardous movement.
connect and remove wet- and/or dryes and isolate aircraft from all sources ty or other spark-producing devices.
lucing static electricity is generated at air hose outlets, so this method should ed for ventilating or purging fuel nove all fuel, oil, and hydraulic fluid.
sh all fuel and oil cells with clean late tires, especially on magnesium epressurize landing gear struts, pneums, and hydraulic accumulators.
scating Engines and Propellers. The would be removed from the engine and from the aircraft. The exterior of the propeller should be washed with ot or cold fresh water.
›r accessories, engine parts, etc., should I and all surfaces flushed with fresh erably hot. If facilities are available, ed parts, size permitting, should be Page 128-1 immersed in hot water or hot oil, 180° F., for a short period of time. Soft water is preferred and should be changed frequently. All parts must be completely dried by air blast or other means. If no heat drying facility is available, wipe the cleaned parts with suitable drying cloths.
Constant speed propeller mechanism should be disassembled, as required, to permit complete decontamination. Clean parts with steam or hot or cold fresh water. Dry the cleaned parts in an oven, but if a heat drying facility is not available, wipe the cleaned parts with suitable drying
d. Gas Turbine, Turboprop and Turboshaft En- The engine exhaust shield, insulation blankets, separate exhaust collectors, compressor housing, pinion cowl and/or upper pinion housing should be removed. The engine accessories, outer housing exhaust shields, and other exposed parts should be steam cleaned. The steamcleaned parts should be dried in an oven at approxímately 200° F., or with hot air from a portable engine heater, or with clean wiping cloths.
Immerse remainder of engine in 10-20 percent water solution of sodium dichromate, or hot, fresh water and apply sufficient agitation to provide complete flushing.
If immersion cannot be accomplished, flood the lower section of the compressor housing and thoroughly flush rotor blades with sodium dichromate solution or warm fresh water. Seal off combustion chamber openings and alternately fill and drain the combustion chamber with fresh water. Dry clean parts in an oven, or use dry air from a portable engine heater or wipe with suitable drying cloths.
e. Airframe. The salvageable components of the fuselage, wings, empennage, seaplane and amphibian hulls and floats, and movable surfaces should be processed as follows:
(1) The fabric from fabric-covered surfaces should be removed and replaced.
(2) The sircraft interior and exterior should be cleaned using steam under pressure with steam-cleaning compound. The steam should be directed into all seams and crevices where corrosive water may have penetrated. Avoid steam * Par 254
*cleaning electrical equipment, such as terminal boards and relays.
(3) Areas that have been steam cleaned should be rinsed immediately with either hot or cold fresh water.
(4) Touch up all scratches and scars on painted surfaces using zinc chromate primer or preservative.
(5) Undrained hollow spaces or fluid entrapment areas should be provided temporary draining facilities by drilling out rivets at lowest point. Install new rivets after drainage.
(6) All leather, fabric upholstery, and insulation should be removed and replaced. Plastic or rubber foam which cannot be cleaned of all to cleanes corrosive water should be replaced.
lar structures should be removed and the structure blown out with compressed air. If corrosive water has reached the tubular interiors, carefully flush with hot, fresh water and blow out water with compressed air. Roll the structure as necessary to remove water from pockets. Fill the tubes with hot linseed oil at approximately 180° F. Drain oil and replace drain plugs or drive screws.
(8) Clean sealed wood, metalite, and other nonmetallic areas, excluding acrylic plastics, with warm water. Wood, metalite, and other porous materials exposed to water immersion should be replaced, unless surfaces are adequately sealed to prevent penetration by corrosive water. Virtually all solvents and phenolic type cleaning agents are detrimental to acrylics and will either
f. Helicopter Rofor Dynamic Components.
(1) All evidence of corrosive water should be removed from the exterior of transmissions and gear boxes by flushing with clean hot or cold fresh water.
(2) Where it is possible that corrosive water has reached the interior of the transmission or gear boxes, remove plugs and/or covers and drain completely. Flush interior of part with hot or cold fresh water. Drain residual water, replace plugs and/or covers, and reapply proper lubricant.
g. Helicopter Blades. Except for blades with wooden or other nonmetallic constructions, treat Par 254 AC 43.1:
helicopter blades the same as propelle ciprocating engines. Clean nonmetal by hand, using warm water. Dry wi cloths or a warm air blast. When clea copter rotor blades, insure that nonsen members, such as the spars and blad are cleaned and dried.
h. Fuel and Oil Systems. Contamir and oil systems should be processed as :
(1) Flush oil system, including li water-displacing preservative.
(2) Open fuel systems. Purge cell lines. Check effectiveness of the pur combustible gas indicator. Remove bli self-sealing type fuel cells and all cal or pads.
(3) Use clean, fresh water to wash After drying, spray interior walls witł
(4) Chemically treat bare metal si cleaned aluminum tanks with 10-21 water solution of sodium dichromate.
(5) Flush fuel lines with hot water maximum). Dry, using clean, dry, a air.
1. Landing Gear. Process salvageab nents of the landing gear, wheels, and follows:
(1) Remove tires and wheels.
(2) Steam clean wheels, rinse in fr and dry.
(3) Remove wheel bearings and cl dry cleaning solvent.
(4) Immerse bearings in methyl al dry the cleaned bearings in air blast.
permit bearings to rotate during air bla Reapply proper lubricant.
(5) Remove brakes, steam clean, :
with fresh water and dry.
I. Electrical Equipment.
(1) Wet cell batteries. The risk in using wet cell batteries that have been in sea water may outweigh any ecor vantage and should be replaced.
(2) Because of possible flight haz later defects caused by progressive cor tack, all electrical wiring immersed sive water should be replaced. If
CHG 1 Page 128-3 shed or sprayed with corrosive water, ughly with clean, fresh water and dry, ressed air. Following compressed air it with water dispensing preservative 1309, Grade A).
laneous Equipment. The following should be thoroughly washed to resalt, and other contaminants. Dry last or other means, and, if required, oper lubricant:
ring and fuselage hydraulic units.
(2) Electric landing gears.
(3) Actuators.
(4) Cables.
(5) Aceumulators.
(6) Hydraulic reservoirs.
(7) Flight control.
(8) Torque tubes and bell cranks.
(9) Heating units, ducts, etc. *
255.-264. RESERVED.
Par 254
13-14 Page 129 Chapter 7. IDENTIFICATION, TESTING, AND INSPECTION
OF MATERIALS Section 1. IDENTIFICATION OF METALS IDENTIFICATION OF STEEL STOCK, The So- Numerala y of Automotive Engineers (SAE) and the Type of steels and digita erican Iron and Steel Institute (A.I.S.I.)
a numerical index system to identify the Carbon Steels ---- 1xxx position of various steels. The numbers as- Plain Carbon Steels 10Xx Free Cutting Steels 11xx ed in the combined listing of standard Manganese Steels (Manganese 1.60 to 1.90%) 18xx la issued by these groups represent the Nickel Steels 2xXX ! of steel and make it possible to readily 8.50% nickel 28xx tify the principal elements in the material. 5.00% nickel 25xx he first digit of the four number designa- Nickel Chromium Steels indicates the type to which the steel be- 8.70% nickel, 0.07% chromium
g. Thus "1" indicates a carbon steel, "2" a 1.25% nickel, 0.60% chromium 1.75% nickel, 2.00% chromium el steel, "¿" a nickel chromium steel, etc. 8.50% nickel, 1.50% chromium he case of simple alloy steels, the second Corrosion and heat resisting -. 80xXX t indicates the approximate percentage of Molybdenum Steels --. 40xx predominant alloying element. The last two Chromfum Molybdenum Steels -. SIZI ›on content. Thus the symbol "1020" indi- ts usually indicate the mean of the range of Nickel Chromium Molybdenum Steels Nickel Molybdenum Steels 1.75% nickel, 0.25% molybdenum 48xx 1ůxx s a plain carbon steel lacking a principal 8.50% nickel, 1.50% chromium 48×x ving element and containing an average of Chromium Steele БxXX percent (0.18 to 0.28) carbon. The symbol Low chromium 51xx 30" indicates a nickel steel of approxi- Medium chromium Corrosion and heat resisting 521XX 61xxx ely 8 percent (8.25 to 8.75) nickel and an Chromium Vanadium Steels - 6XІX *age of 0.30 percent, (0.28 to 0.88) carbon 1.00% chromium -- 61xx ent. The symbol "4180" indicates a chro- National Emergency Steels 8xxx m-molybdenum steel of approximately 1 Silicon Manganese Steels 9xxx 'ent (0.80 to 1.10) chromium, 0.20 percent 2.00% silicon -- 82xI 5 to 0.25) molybdenum, and 0.80 percent 8 to 0.83) carbon. The basic numbers for FIGURE 7.1.-Numerical system for steel identification.
four digit series of the carbon and alloy Is may be found in figure 7.1.
forming to Specification MIL-1-6786 are in- INTERCHANGEABILITY OF STEEL TUBING. terchangeable.
"1025" welded tubing as per Specification -T-5066 and "1025" seamless tubing conning to Specification MIL-T-5066A are inhangeable.
c. NE-8630 welded tubing conforming to Specification MIL-T-6784, and NE-8680 seamless tubing conforming to Specification MIL-T-6782 are interchangeable.
, "4130" welded tubing as per Specification 267. IDENTIFICATION OF ALUMINUM. To pro- ~T-6781, and "4180" seamless tubing con- vide a visual means for identifying the various Par 265
Page 130 AC 4 grades of aluminum and aluminum alloys, such metals are usually marked with symbols such as Government Specification Number, the temper or condition furnished, or the commercial code marking. Plate and sheet are usually marked with specification numbers or code markings in rows approximately 5 inches Nonbeat-treatable Alloye Temper designation Defnition Annealed recrystallized (wrought products only) applies to softest temper of wrought producta.
-H12 Strain-hardened one-quarter-hard temper.
-H14 Strain-hardened half-hard temper.
-H16 Strain-hardened three-quarters• hard temper.
-H18 Strain-hardened full-bard temper, -H22 Strain-bardened and partially annealed to one-quarter-bard temper.
-H24 Strain-hardened and partially annealed to balf-hard temper.
-H26 Strain-hardened and partially annealed to three-quarters-hard temper.
-1128 Strain-bardened and partially annealed to full-hard temper.
-H82 Straln-hardened and then lized. Final temper la one-quarter -H84 Strain-hardened and then stabilized. Final temper is one-half -9186 Strain-bardened and then stabilized. Final temper is three quarters hard.
-#88 Strain-bardened and then stabllized. final temper is full-hard.
-H112 As fabricated; with specified mechanical property limita.
For wrought alloys; as fabricated.
No mechanical properties limits.
For cast alloys; as cast.
apart. Tubes, bars, rods, and extruded s are marked with specification numbers or markings at intervals of 8 to 5 feet alon length of each piece. The commercial marking consists of a number which iden the particular composition of the alloy. Ir dition, letter suffixes designate the follov Heat-trentable Alloya Temper designation Dennition -0 Annealed recryatallized producta only) applies to a temper of wrought products.
-12 Annealed (castinge only).
-T8 Solution beat-treated worked by the Battening atraightening operation.
-T86 Solution heat-treated and worked by reduction of 6 per -T4 Solution heat-treated.
-T42 Solutlon heat-treated by the regardieas of prior temper plicable only to 2014 and -T5 Artifcially aged only (cas only).
-T6 Solution heat-treated and artific aged.
-782 Solution heat-treated and age user regardless of prior te (applicable only to 2014 and alloys).
-T851, -T451, Solution heat-treated and stres -T8510, -78511 lieved by stretching to produ -T4510, -T4511. permanent set of 1 to 8 per depending on the product.
-T651, -T851, Solution heat-treated, stress rel!
-76510, -T8510, by stretching to produce a I -78511, -78511. anent set of 1 to 8 percent, artificially aged.
-T852 Solution heat-treated, compress produce a permanent set and artificially aged.
-T81 Solution heat-treated, cold-wo by the fattening or straighte operation, and then artific aged.
-T86 Solution heat-treated, cold-wo by reduction of 6 percent, and artificially aged.
For wrought alloys; as fabric No mechanical properties Ill For cast alloys; as cast.
FIGURE 7.2.-Basic temper designations and subdivisions for aluminum alloys.
Par 267
3.13-1A Clad aluminum alloys have surface layers of e aluminum or corrosion-resistant alumin alloy bonded to the core material to inpit corrosion. Presence of such a coating may determined under a magnifying glass by exination of the edge surface which will show ree distinct layers.
b. Test for Distinguishing Heat-Treatable and inheat-Treatable Aluminum Alloys. If for any ason the identification mark of the alloy is t on the material, it is possible to distinguish tween some heat-treatable alloys and some nheat-treatable alloys by immersing a same of the material in a 10 percent solution of ustic soda (sodium hydroxide). Those heateated alloys containing several percent of ap 7 Page 131 copper (2014, 2017, and 2024) will turn black due to the copper content. High copper alloys when clad will not turn black on the surface, but the edges will turn black at the center of the sheet where the core is exposed. If the alloy does not turn black in the caustic soda solution it is not evidence that the alloy is not heat-treatable, as various high strength heattreatable alloys are not based primarily on the use of copper as an alloying agent. These include among others 6058, 6061, and 7075 alloys. The composition and heat-treatability of alloys which do not turn black in a caustic soda solution can be established only by chemical or spectro-analysis.
268.-278. RESERVED.
Par 267
Page 132 AC 43.
Section 2. TESTING OF METALS
279. HARDNESS TESTING. Hardness testing provides a convenient means for determining, within reasonable limits, the tensile strength of steel. It has several limitations in that it is not suitable for very soft or very hard steels.
In hardness testing, the thickness of the specimen being tested and the edge distance should be such that distortion of the metal due to these factors is eliminated. Several readings should be taken and the results averaged. In general, the higher the tensile strength, the greater is its hardness. Common methods of hardness testing are outlined in the following paragraphs. These tests are suitable for determining the tensile properties resulting from the heat treatment of steel. Care should be taken to have case hardened, corroded, pitted, decarburized, or otherwise nonuniform surfaces removed to a sufficient depth. Also, exercise caution not to cold-work and consequently harden the steel during removal of the surface.
The relationship between tensile strength and hardness is indicated in figure 7.3.
282. VICKERS HARDNESS TEST. In this test small pyramidal diamond is pressed into metal. The hardness number is the ratio of load to the surface area of indentation.
283. TESTING ALUMINUM. Hardness tests :
useful for testing aluminum alloy chiefly a means of distinguishing between anneal cold-worked, heat-treated, and heat-trea and aged material. It is of little value in in cating the strength or quality of heat tre ment. Typical hardness values for alumin alloys are shown in figure 7.4 FIGURE 7.4.-Hardness values for aluminum alloy!
Brinell numb Material commercial Eardnesa 500 kg. lom designation temper 10 mm. ball 1100 A18 8008 H16
280. BRINELL HARDNESS TEST. In this test a 2014 standard load is applied to a smooth surface of T8 185 2017 45 metal through a hardened steel ball, one centi- 18 105 meter in diameter. The numerical value of Bri- 2024 47 nell hardness is equal to the load divided by T· 120 the surface area of the resulting spherical im- 2025 T8 110 pression. 8151 100 5052 47 H86 78
281. ROCKWELL HARDNESS TEST. In this test, a 6061 80 standard minor load is applied to seat a hard- 65 ened steel ball or a diamond cone in the surface 95 of the metal, followed by the application of a 7075 185 standard major load. The hardness is meas- 7079 185 T6 185 75 ured by depth of penetration. Rockwell super- 220 T4 ficial hardness tests are made using light 0855 T6 minor and major loads and a more sensitive A856 system for measuring depth of indentation. It is useful for thinner sections, very small parts,
284.-294. RESERVED.
Par 279 Char
Rockwell, superficial bardness Brinell bardness number Rockwell hardness number number, superfielal brale 10-mm. ball, 3000-kg. load penetrator Tenaile Diamond Shore etrengths Hockwell pyramid A-scale, B-scale, D-scale, sclero- (approxi- Rockwell bardness numbers C-scale (Vickers) hardness number ard ball Stand- Kult- gren ball penetra- 60-kz. load, brale 1/16-1n. 100-kg load, diam. penetra- 100-kg. lond, brale 15-kg. 15-N acale, load 30-kg. scale, 30-N load 45-kg. 45-N load scale, hardness number всоре mate) in P. 8. 1. 1000 bardness number® C-scale tor ball tor Col. 1 Col. 2 Col. 3 Col. 4 Col. 5 Col. 6 Col. 7 Col. 8 Col. 9 Col. 10 Col. 11 Col. 12 Col. 13 Col. 14 68 -- 940 85.6 76.9 93.2 84.4 75.4 97 68 67 900 85.0 76.1 92.9 83.6 74.2 95 67 66 865 84.5 75.4 92.5 82.8 73.3 92 66 65 832 739 83.9 74.5 92.2 81.9 72.0 91 65 64 800 722 83.4 73.8 91.8 81.1 71.0 88 64 63 772 705 82.8 73.0 914 80.1 69.9 87 63 62 746 688 82.3 72.2 91.1 79.3 68.8 62 61 720 670 81.8 71.5 90.7 78.4 67.7 83 61 60 697 613 654 T18 70.7 90.2 77.5 66.6 81 60 59 674 599 $£9 1°09 6*69 8°68 76.6 65.5 80 326 59 58 653 587 919 I°08 769 £*68 75.7 64.3 78 315 58 57 633 575 969 9'62 5*89 6*88 S72 63.2 76 305 57 56 613 561 LIS 0°62 L'19 73.9 62.0 75 295 56 55 595 546 099 S81 6°99 87.9 73.0 60.9 74 287 55 54 577 534 543 0°82 1°99 #°48 72.0 59.8 72 278 54 53 560 519 £ZS F°LL 6°98 71.2 58.6 71 269 53 52 544 500 508 ZIS 8°94 9°F9 1°98 70.2 57.4 69 262 52 51 528 487 494 96₺ £94 8°89 698 69.4 56.1 68 253 51 50 513 475 481 IS₺ 6°9L T°£9 68.5 55.0 67 245 50 49 498 464 469 69₺ 1°29 0°S8 67.6 53.8 66 239 49 48 484 451 455 SS₺ LYL £₺8 66.7 52.5 64 232 48 47 471 442 443 £FT I°72 8°09 6°&8 8"99 51.4 68 225 47 46 458 432 432 ZET 9EL 0°09 S£8 8*79 50.3 62 219 46 See footnotes at end of table
FIGURE 7.3.-Rockwell C scale steel hardness numbers comparison table-continued.
Brinell hardness number Rockwell, superficial hardness 10-mm. ball, 8000-kg. load Rockwell bardness numbers number, superficial brale penetrator Tenalle Rockwell bardnede number* C-scale (Vickera) hardness Diamond pyramid number ard ball Stand- Hult- gren ball carbide Tung- sten- ball penetra- A-scale, 60-kg. load, brale B-scale, 1/16-10. 100-kg. load, diam. D-scale, 100-kg. penetra- load, brale 15-kg. scale, 15-N load 80-kg. scale. 30-N load 45-58. scale, 45-N load hardness number Shore scope sciero- strengtha (approxi- mate) in D. e. I. 1000 hardness Rockwell numbers C-scale tor ball tor Col. 1 Col. 2 Col. 3 Col. 4 Col. 5 Col. 6 Col. 1 Col. 8 Col. 9 Col. 10 Col. 11 Col. 12 Col. 13 Col. 14 446 421 421 421 731 59.2 83.0 64.0 49.0 60 212 45 434 409 409 409 725 58.5 82,5 63.1 47.8 58 206 44 423 400 400 400 72.0 57.7 82.0 62.2 46.7 57 201 43 412 390 390 390 71.5 56.9 81.5 61.3 45.5 56 196 42 402 381 381 381 70.9 56.2 80.9 60.4 44.3 55 191 41 392 371 371 371 70.4 55.4 80.4 59.5 43.1 54 186 40 382 362 362 362 69.9 54.6 79.9 58.6 41.9 52 181 39 372 353 353 353 69.4 538 79.4 57.7 40.8 51 176 38 363 344 344 344 68.9 53.1 78.8 56.8 39.6 50 172 37 354 336 336 336 68.4 (109.0) 52.3 78.3 55.9 38.4 49 168 36 345 327 327 327 67.9 (108.5) 51.5 77.7 55.0 37.2 48 168 35 336 319 319 319 67.4 (108.0) 50.8 77.2 54.2 36.1 47 159 34 327 311 311 311 66.8 (920I) 50.0 76.6 53,3 34.9 46 154 33 318 301 301 301 66.3 (107.0) 49.2 76.1 52.1 33.7 44 150 32 310 294 294 294 65.8 (106.0) 48.4 75.6 51.3 32.5 43 146 31 302 286 286 286 65.3 (105.5) 47.7 75.0 50.4 31.3 42 142 30 294 279 279 279 64.7 (104.5) 47.0 74.5 49.5 30.1 41 188 29 286 271 271 271 64.3 (104.0) 46.1 73.9 48.6 28.9 41 184 28 279 264 264 264 63.8 (103.0) 45.2 73.3 47.7 27.8 40 131 272 258 258 258 63.9 (102.5) 44.6 72.8 46.8 26.7 38 197 26 266 253 253 253 62.8 (101.5) 43.8 72.2 45.9 25.5 38 124 25 260 247 247 247 62.4 (101.0) 49.1 71.6 45.0 24.3 37 121 24 254 243 243 243 62,0 100.0 42.1 71.0 44.0 23.1 36 118 23 248 237 237 237 61.5 99.0 41.6 70.5 43.2 22.0 35 115 22 243 231 231 231 61.0 98.5 40.9 69.9 42.3 20.7 35 113 21
PIGUKE TO -доскжен ~ осас і 20_ 238 226 226 226 60.5 97. 8 40. 1 69-4 $1.5 19. 6 110 20 3.13-14
(18) - 230 219 219 219 96. 7 (18)
(16) 222 212 212 212 95. 5
(14) 213 203 203 203 93. 9
(12) 204 194 194 194 92. 3
(10) 196 187 187 187 90. 7 188 179 179 179 89. 5 180 171 171 171 87. 1
(4) 173 165 165 165 85. 5
(2) 166 158 158 158 83. 5
(0) - 160 152 152 152 81. 7 : The values in this table shown in bold-face type correspond to the values shown in the corresponding joint SAE-ABM-ASTH Committee on Hardoess Conversions as printed in ABTH E4S, table 2.
• Values in () are beyond normal range and are given for information only.
* It is possible that steels of various compositions and processing historles will deviate in hardness-tensile strength relationship from the data pres nted in this table. Above the level of Rockwell C43, deviation increases with increasing hardness and the table shall not be used above Bo 48 ercept in the absence of other data specifcally approved by the procuring agency.