Aluminium Silicon Bronze AMS 4631 (UNS C64200)

Technical Data Sheet

Chemical Composition Limits
Weight % Cu Al As Fe Pb Mn Ni Si Sn Zn
AMS 4631
Rem 6.3 - 7.6 0.09 0.3 0.05 0.10 0.25 1.5 - 2.2 0.20 0.50

AMS 4631 (UNS C64200) Silicon aluminum bronze combines the self lubricity of the silicon with the higher mechanical properties of aluminum bronze and is sometimes used in place of C63000 where specifications permit. C64200 is free-machining and has good anti-galling and anti-seizing properties. Typical applications involve valve stems, gears, marine and pole line hardware, wing pylons, bolts, nuts, bushings and valve body components.

Typical Mechanical Properties

Material Size

Tensile Strength ksi

Yield Strength ksi Elongation 4D %
AMS 4631 <0.5" 90 45 9
AMS 4631 0.5" - 1.00" 85 45 12
AMS 4631 1.00" - 2.00" 80 42 12
AMS 4631 2.00" - 3.00" 75 35 15

Physical Properties - AMS 4631
Melting Point - Liquidus - 1840 F
Melting Point - Solidus - 1800 F
Density - 0.278 lb/in3 at 68 F
Specific Gravity - 7.69
Electrical Resistivity - 113.0 ohms-cmil/ft @ 68 F
Electrical Conductivity - 8 %IACS @ 68 F
Thermal Conductivity - 26.0 Btu · ft/(hr · ft2·oF)at 68F
Coefficient of Thermal Expansion - 10.0 ·10-6 per oF (68-572 F)
Specific Heat Capacity - 0.09 Btu/lb/oF at 68 F
Modulus of Elasticity in Tension - 16000 ksi
Modulus of Rigidity - 6000 ksi
Machinability Rating - 60

Sizes available: AMS 4631 & AMS 4634
SOLID BAR 3/16” - 8” diameter
HEX BAR 5/8" - 2 1/2
For all other stock availability contact Sales.


BS 2872
BS 2874
DGS 8453A
DGS 1044
NES 834
AMS 4631
AMS 4634
SAE J463
SAE J461
BS EN12163
BS EN12164
BS EN12165
BS EN12167
BS EN12420

Typical Uses of Aluminium Bronze AMS 4631
Aerospace - Landing Gear Bushings & Bearings, Valve Guides, Stems,and Seats
Other Industrial - Corrosion Resistant Parts, Wear Rings, Machine Tool Parts,Piston Guides, Worm Wheels, Hot Mill Gurdes
Marine - Propeller Hubs, Wear Rings, Hardware, Worm Gears, Shafts, Sleeves.

At Aircraft Materials all stock items can be shipped out within 24 hours, usually within the same day. Even cutting orders for bar or sheet can be processed and dispatched the same day, and for time-critical situations such as AOGs, we have a dedicated AOG service desk ready to help (

Thanks to our global logistics network we can source from anywhere in the world in just a few days. We use a range of transport partners to enable us to ship overnight within the U.K. and Europe and provide fast shipping solutions to the rest of the world. If your requirement is urgent we can offer a priority shipping service, but also if time is not so critical we can offer more cost-effective options to ensure you get the best value for money. To find out more about our services click here.

Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.

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