Product Information Tungsten Balance Weights

Our machineable high-density tungsten alloys, with a density over 60 % higher than lead, help stabilize helicopter rotor blades and the control surfaces of ailerons, elevators, and rudder sections:

• Aircraft and Helicopter Tungsten Balance Weights
• 
Instrumentation Tungsten Balance Weights

• Vibration Dampening Tungsten Weights



Produced and Certified to AMS-T-21024, AMS 7725 and ASTM B777.

Customer Collaboration with Tighter Process Controls

As a vertically integrated manufacturer, we exercise tight control of all our processes from refining the raw materials to delivering high purity finished products. H.C. Starck has a unique global reach allowing for close contact and collaboration with our customers. Our experienced Research and Development department allows us to constantly be at the forefront of technological advancement and development of new products together with our partners in the industry.

H.C. Starck supplies the following tungsten alloys:

Kulite® and HPM Tungsten Alloys

H.C. Starck supplies the long established Kulite® tungsten alloys from the U.S. (Table 1) and HPM tungsten alloys from Germany (Table 2).

Table 1 - Kulite® tungsten alloys (K1700 thru K1850)

Alloy Designation		K1700	K1701	K1750	K1800	K1801	K1850
Tungsten content	(%)	90	90	92.5	95	95	97
Density	(g/cm3)	17	17	17.5	18	18	18.5
	(lb/in3)	0.61	0.61	0.63	0.65	0.65	0.67
Hardness	(Rc)	23	22	24	25	24	26
Ultimate Tensile Strength	(psi)	125,000	110,000	125,000	125,000	110,000	120,000
	(N/mm2)	860	760	860	860	760	830
Yield Strength	(psi)	85,000	80,000	90,000	90,000	85,000	95,000
	(N/mm2)	590	550	620	620	590	660
Elongation	%	12	4	10	8	2	6
Modulus of Elasticity	(psi x 106)	45	40	46	48	45	50
	(kN/mm2)	310	280	320	330	310	345
Magnetic Properties		slight	none	slight	slight	none	slight
Magnetic Permeability	(µ)	>1.05	<1.05	>1.05	>1.05	>1.05	<1.05
Thermal Expansion Coefficient	(x 10-6/K) (20 °C - 500 °C)	5.1	5.4	4.9	4.8	5.0	4.8
Thermal Conductivity	(cgs)	.20	.23	.24	.27	.32	.26
Electrical Conductivity	(% IACS)	11	14	12	15	16	16
MIL-T-21014(D)	class	1	1	2	3	3	4
ASTM B777	class	1	1	2	3	3	4

Table 2 - HPM tungsten alloys

Typical properties of tungsten composite materials

Inspection criterion		HPM 1700	HPM 1710	HPM 1701	HPM 1705	HPM 1750	HPM 1750 sheet
Tungsten content	%	90.0	90.0	90.0	90.0	92.5	92.5
Density	g/cm³	17.0 ± 0.2	17.0 ± 0.2	17.0 ± 0.2	17.3 ± 0.2	17.5 ± 0.2	17.6 ± 0.2
Hardness	HV 30	≤ 320	≤ 320	≤ 320	≤ 360	≤ 325	≤ 460
Tensile strength (typical value)	MPa	850	850	670	900	840	870
Minimal yield strengt	MPa	520	520	520	520	520	520
Elongation (typical value)	%	12	12	3	8	14	16
Young’s modulus (average value)	GPa	320	320	300	330	340	340
Median coefficient of linear thermal expansion 20 – 100 °C	10-6/K	6.1	6.3	6.0	4.5	5.5	5.5
20 – 300 °C	10-6/K	6.2	6.5	6.2	5.1	5.7	5.7
20 – 450 °C	10-6/K	6.3	6.6	6.4	5.3	5.8	5.8
Thermal conductivity	W/mK	≥70	≥70	≥90	≥70	≥75	≥75
Electrical conductivity (average value)	%IACS MS/m	11 6.4	11 6.4	14 8.1	13 7.5	12 6.9	12 6.9
Specific electrical resistance (average value)	µΩm	0.16	0.16	0.12	0.13	0.15	0.15
Permeability µ		> 1.05	> 1.05	< 1.05	> 1.05	> 1.05	> 1.05

Inspection criterion		HPM 1751	HPM 1760	HPM 1800	HPM 1810	HPM 1801	HPM 1850	HPM 1850W
Tungsten content	%	92.5	92.5	95.0	95.0	95.0	97.0	97.0
Density	g/cm³	17.5 ± 0.2	17.6 ± 0.2	18.0 ± 0.2	18.0 ± 0.2	18.0 ± 0.2	18.5 ± 0.2	18.5 ± 0.2
Hardness	HV 30	≤ 325	≤ 325	≤ 332	≤ 332	≤ 332	≤ 340	≤ 340
Tensile strength (typical value)	MPa	690	870	830	830	700	830	890
Minimal yield strengt	MPa	520	520	520	520	520	520	520
Elongation (typical value)	%	3	16	14	14	2	12	12
Young’s modulus (average value)	GPa	330	340	370	370	330	380	380
Median coefficient of linear thermal expansion 20 – 100 °C	10-6/K	5.7	5.5	4.9	5.2	5.4	5.1	4.8
20 – 300 °C	10-6/K	5.8	5.8	5.1	5.3	5.5	5.1	4.9
20 – 450 °C	10-6/K	5.9	5.9	5.2	5.5	5.6	5.2	5.0
Thermal conductivity	W/mK	≥85	≥75	≥80	≥80	≥85	≥75	≥80
Electrical conductivity (average value)	%IACS MS/m	15 8.5	12 6.9	13 7.7	13 7.7	15 9.0	16 9.3	16 9.3
Specific electrical resistance (average value)	µΩm	0.12	0.15	0.14	0.14	0.11	0.10	0.10
Permeability µ		< 1.05	> 1.05	> 1.05	> 1.05	< 1.05	> 1.05	> 1.05