SP 181 Master Alloys For Gold, Color : Indian Yellow

Composition (Wt. %) : Ag 23, Cu 65, Zn + Deoxidizers- BAL.
Carat : 18 - 22
Colour : Indian Yellow
Melting Temp of Alloy : 890 Ce.
Application: The alloy SP 181 is the most widely used alloy for diamond jewelry. It imparts
right set of properties which helps artisans to achieve firm diamond setting. It also gives a
color which is popular for 18 carat diamond studded Indian jewelry.
Recommended Practice:
18K 22K
Application : Casting H-made Casting H-made
Alloying Temp. : 1040C - 1060C 1060C - 1080C
Casting Temp. : 1020C - 1050C 1050C - 1070C
Flask Temp. [Normal Cast] : 630C - 650C 640C - 660C
Flask Temp. [Stone Cast] : 610C - 630C 620C - 640C
Quenching Time : 10 - 15 minutes. 15 - 25 minutes
Notes:
1) The 18 carat casings have a tendency to get hardened and subsequently give
problems of cracking especially when flasks are cooled very slowly. For this reason,
it is recommended that the flasks are cooled as fast as permitted by the quality of
diamonds and also by the design parameters.
2) Pre-Alloying is strongly recommended simply to ensure better homogeneity in
castings as well as in hand made products. Also, for still better results, pre-alloying
in an inert atmosphere is always preferred.
4) Cast Tree Cleaning & Drying procedure: After primary removal of the investment
during quenching, submerge tree in a hot (80-100oC) 50% phosphoric acid
solution for 15-20 minutes. Rinse well with cool water to remove remaining
investment powder and base metal oxides. Dry with compressed air.