Special Alloys
KIYOMINE ALLOYS

To meet diverse customer needs, Kiyomine Metal offers a wide lineup of special alloys, beginning with the Corson Alloy KA250.

Special Alloys
(KIYOMINE ALLOYS)

To meet diverse customer needs, Kiyomine Metal offers a wide lineup of special alloys, beginning with the Corson Alloy KA250.

Kiyomine Alloys Lineup

In addition to nickel silver and phosphor bronze, Kiyomine’s special alloys are distinctive, high‑performance, and high‑quality products developed to meet further customer needs.

Corson Alloy:KA250

KA250 is a Corson-type alloy that offers an excellent balance between strength and electrical conductivity. It has superior heat resistance, making it resistant to thermal deformation.
Furthermore, it exhibits excellent high-temperature creep resistance, minimal anisotropy in mechanical properties, good bendability, and outstanding solderability and plateability.

Phosphor Bronze-Based Alloy: KA1025

KA1025 is a material developed by adding a trace amount of nickel to phosphor bronze containing 10% tin, significantly enhancing its strength and spring properties compared to conventional spring-grade phosphor bronze.
It forms a stable, refined microstructure, resulting in consistently high-quality products with minimal variation.
This alloy combines high strength, excellent spring characteristics, and superior bendability, making it suitable for more severe bending applications.

Phosphor Bronze-Based Alloy: MF202 (C50710)

MF202 is a phosphor bronze alloy composed of copper containing approximately 2% tin, with minor additions of nickel and phosphorus.
It features high electrical conductivity combined with strength comparable to that of phosphor bronze (C5111), making it particularly suitable for use in electronic devices.

Nickel Silver-Based Alloy: MB115 (C73150)

MB115 is a nickel silver alloy composed mainly of copper, nickel, and zinc. It retains the typical characteristics of conventional nickel silver, while offering enhanced electrical conductivity and improved solderability.

Composition and Properties Overview

Chemical Composition

Product NamePhosphor BronzeCorsonPhosphor BronzeNickel silver
Alloy NameCDA No.Sn-Ni-P alloyCorson alloyC50710C73150
JIS No.KA1025KA250MF202MB115
Chemical Composition
[wt.%]
CuRemRemRemRem
Zn---0.29.0-13.0
Fe---0.1-0.25
Ni0.2-0.351.6-2.20.1-0.44.0-7.0
Sn9.0-11.0-1.7-2.3-
P0.03-0.35--0.15-
Si-0.4-0.8--
Mn--0.5--0.5

Physical Properties

Product NameKA1025KA250MF202MB115
Melting Point [℃]1070108010651070
Poisson's Ratio0.330.33--
Specific Gravity8.88.98.888.77
Electrical Conductivity
[%IACS]
12423215
Thermal Conductivity
[W/m・K (20℃)]
55160155-
Elastic Modulus [GPa]110127125120
Coeff. of Thermal Expansion
[ppm/K (20~300℃)]
181617-

Mechanical Properties

Product NameKA1025KA250MF202MB115
Tensile Strength [MPa]O--315-315-
1/4H----
1/2H640-740-410-510390-490
H700-800640-740490-590460-560
EH800-900-540-635530-630
SH850-950-610-705-
ESH950-1050---
XSH1000----
0.2% Proof Strength [MPa] O----
1/4H----
1/2H----
H560-600---
EH680----
SH800----
ESH920----
XSH980----
Elongation [%]O--30-25-
1/4H----
1/2H29--15-5-
H15-5-5--
EH6--2--
SH2----
ESH1----
XSH----
Vickers Hardness [HV]O--70-115-
1/4H----
1/2H190-220-125-165110-
H220-260195-240150-185135-
EH240-290-175-205150-
SH270-310-185--
ESH300----
XSH320----