Looser Bronze 68 (LB 68) – CuSn12Ni2-C-GS/GC/GZ DIN EN 1982
Looser Bronze 68 is a construction material with very high wear resistance and good resistance to cavitation stress. It is insensitive to impact and resistant to seawater and corrosion.
Chemical composition (DIN EN 1982:2017-11)
Element Cu Sn Ni P Zn Pb Fe Mn Sb S Al Si
Min. [%] 84.5 11 1.5 0.05 - - - - - - - -
Max. [%] 87.5 13 2.5 0.4 0.4 0,3 0,2 0,2 0,1 0,05 0,01 0.01
Mechanical properties (DIN EN 1982:2017-11)
Continuous casting-GC Centrifugal casting-GZ
Yield point Rp0,2 [N/mm2] ≥ 180 ≥ 180
Tensile strength Rm [N/mm2] ≥ 300 ≥ 280
Brinell hardness [HB] ≥ 95 ≥ 95
Elongation at fracture A [%] ≥ 10 ≥ 8
Bending fatigue strength* Rbw [N/mm2] ± 140 ± 140
Modulus of elasticity** E [kN/mm2] 90 90
* Guideline value with 108 load cycles and at 20°C / ** Guideline value
The sample bar is removed from the casting in the case of centrifugal castings and continuous castings. The sample position – e.g. lengthwise or crosswise sample – must be agreed between orderer and manufacturer: the values specified in the table apply only to wall thicknesses up to 50 mm for the blank casting. In the case of wall thicknesses over 50 mm, with the wall thickness of the blank casting being the decisive factor, it must be anticipated that the strength and hardness values are lower. This applies in particular to the yield point.
It must not be expected that the strength and hardness values are uniformly high at all points of the casting. In general, the values in the outer layers will be higher than in the core zone.
Worm-gear loading characteristics (c values)
Centrifugal casting Mould casting
Continuous operation without cooling 8 N/mm2 with v = 2 m/s
2.2 N/mm2 with v = 8 m/s6.5 N/mm2 with v = 2 m/s
1.8 N/mm2 with v = 8 m/s
Continuous operation with cooling 8.5 N/mm2 with v = 2 m/s
12.5 N/mm2 with v = 8 m/s7 N/mm2 with v = 2 m/s
10 N/mm2 with v = 8 m/s
Short duty cycle [ED] 45 N/mm2 (ED max. 5%) 35 N/mm2 (ED max. 5%)
Physical properties (Guideline values)
Coefficient of thermal expansion [10-6/K] 17.5 Electrical conductivity [m/Wmm2] 6.2
Thermal conductivity [W/mK] 54 Specific gravity [kg/dm3] 8,6
Standards
DIN EN 1982 CuSn12Ni2-C-GS/GC/GZ DIN 1705 G/GC/GZ-CuSn12Ni
Material designation
DIN EN 1982 DIN 1705
Abbreviated designation Number Casting method Abbreviated designation Number
CuSn12Ni2-C-GS CC484K-GS GS or G G-CuSn12Ni 2.1060.01
CuSn12Ni2-C-GZ CC484K-GZ GZ GZ-CuSn12Ni 2.1060.03
CuSn12Ni2-C-GC CC484K-GC GC GC-CuSn12Ni 2.1060.04
GS = G = Sand casting; GZ = Centrifugal casting; GC = Continuous casting
Example uses
- Looser Bronze 68 is a special alloy with ideal running properties for highly stressed worm wheels with high surface pressures and high sliding speeds. Used in worm gears with a high duty cycle, in elevator and escalator drives as well as for highly stressed spindle nuts that are moved under load.
- Finished casting for highly stressed fittings and pump housings.
Machinability
Satisfactory machinability, suitable for welding and soft soldering, limited hard soldering capability.
Sliding partners
As hard as possible (at least 58 HRC) and neatly ground, very finely ground or lapped for the highest loads.
Looser Bronze 68 – Availability
- Over 40 sizes of tubular and round bars are available at short notice.
- Centrifuged rings and bushings pre-turned to the rough sizes or contour.
- Special continuous-casting production processes for hollow and solid profiles as of 1,000 kg per size.
- Ready-to-install parts in accordance with customer drawing.
We will be more than pleased to advise you.
Subject to technical modifications; no responsibility is accepted for the accuracy of this information.