Technical Data
Beryllium Copper is our specialty. We have pioneered the use of this metal since its commercial inception and have led in its development and uses.
BERYLLIUM COPPER
C17200 Tempered, 25 Alloy
Tempered Beryllium Copper was developed by Little Falls Alloys to supply the springs industry with a Beryllium Copper wire that could be used on conventional coiling equipment to provide springs to close tolerance without the necessity of heat treatment. The advantages: Springs are not discolored by heat treatment, thus require no pickling and cleaning.
Springs are free of heat-treat distortion, giving close tolerance without expensive fixtures. Spring Coilers without heat treat facilities can supply Beryllium Copper springs. Pretensioned extension springs can be wound, which is not possible with heat treatable Beryllium Copper.
The disadvantages: Since the temper comes from cold work, the tempered wire spring is not useable at as high a temperature as heat treated Beryllium Copper. Tempered Beryllium Copper has been used in all applications listed for Heat Treated Beryllium Copper.
| COMPOSITION BERYLLIUM COPPER C17200 |
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| ELEMENT | PERCENT | ||
|
NOMINAL
|
MINIMUM
|
MAXIMUM
|
|
| Copper | 98.1 | – | – |
| Beryllium | 1.90 | 1.80 | 2.0 |
| Cobalt & Nickel | – | .20 | – |
| Cobalt & Nickel & Iron | – | – | .60 |
| Cu + Be + Co + Ni + Fe | – | 99.50 | – |
| Silicon | – | – | .20 |
| Aluminum | – | – | .20 |
| Lead | – | – | .20 – .60 (C17300) |
| PHYSICAL PROPERTIES BERYLLIUM COPPER C17200 |
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|
HEAT TREATED CONDITION
|
ENGLISH UNITS | METRIC UNITS |
| Melting Range | 1590 – 1800АF | 870 – 980АC |
| Density | .302 lb/cu in. @ 68АF | 8.35 gm/cm@ 20АC |
| Specific Gravity | 8.26 | 8.26 |
| Coefficient of Thermal Expansion | .0000099 per АF (68-572АF) | .0000178 per АC (20-300АC) |
| Thermal Conductivity | 62-75 BTU/sq ft/ft/hr/АF @ 68АF | .26-.31 cal/sq cm/cm/sec/АC @ 20АC |
| Electrical Resistivity | 46.2 Ohms-circ mil/ft @ 68АF | 7.68 microhm – cm @ 20АC |
| Electrical Conductivity | 19-28% Copper IACS @ 68АF | .110-.163 megohm cm @ 20АC |
| Specific Heat | .10 BTU/lb/АF @ 68АF | .10 cal/gm/АC @ 20АC |
|
Modulus of Elasticity (tension)
|
18,500 KSI* | 13,000 kg/sq mm |
| Modulus of Rigidity (torsion) | 7,300 KSI | 5,000 kg/sq mm |
| Stress Relief Temperature | 400-500АF – 30-60 minutes | 205-260АC – 30-60 minutes |
* 1 KSI equals 1,000 PSI
Compression Springs should be stress relieved to eliminate undesirable cooling stresses —
450АF for 30 minutes is typical.
| MECHANICAL PROPERTIES BERYLLIUM COPPER C17200 |
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| For Round and Square Tempered Spring Wire | ||
|
SIZE
|
TENSILE STRENGTH
|
|
| KSI* | MPa** | |
| .001 to .010 inclusive | 185-240 | 1310-1520 |
| Over .010 to .0253 inclusive | 180-210 | 1240-w1450 |
|
Over .0253 to .050 inclusive
|
165-200 | 1170-1380 |
| Over .050 to .075 inclusive | 140-165 | 1030-1240 |
| MECHANICAL PROPERTIES BERYLLIUM COPPER C17200 |
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| For Tempered Round Wire ASTM B197 | ||
| SIZE | TENSILE STRENGTH | |
| KSI* | MPa** | |
| .050 to .075 Inclusive | 140-165 | 970-1140 |
| Over .075 to .100 inclusive | 120-140 | 830-970 |
| Over .100 to .114 inclusive | 115-130 | 795-900 |
| MECHANICAL PROPERTIES BERYLLIUM COPPER C17200 |
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| For Tempered Flat Wire ASTM B194 | ||||
| DESIGNATION | TENSILE STRENGTH | YIELD STRENGTH | ||
| KSI* | MPa** | KSI* | MPa** | |
| AM (TM00) | 100-110 | 690-760 | 75-90 | 520-620 |
| 1/4 HM (TM01) | 110-120 | 760-830 | 90-110 | 620-760 |
| 1/2 HM (TM02) | 120-135 | 830-930 | 100-125 | 690-860 |
| HM (TM04) | 135-150 | 930-1030 | 115-135 | 790-930 |
| SHM (TM05) | 150-160 | 1030-1100 | 125-140 | 860-970 |
| XHM (TM06) | 160-175 | 1100-1210 | 145-170 | 1000-1170 |
| XHMS (TM08) | 175-190 | 1210-1310 | 155-180 | 1070-1240 |
Beryllium Copper Flat Wire is supplied with either round or square edges. It is conveniently supplied to the same temper ranges as mill hardened strip although produced by a different process.
* 1 KSI equals 1,000 PSI
** 1 KSI equals 6.894,757 MPa (Megapascal)
BERYLLIUM COPPER, C17200