Abstract: This free-cutting copper alloy casting contains: 76.0-79.0% Cu, 3.1-3.6% Si, 0.36-0.85% Sn, 0.06-0.14% P, 0.022-0.10% Pb, with the remainder being made up of Zn and unavoidable impurities. This composition satisfies the following relations: 75.5?f1=Cu+0.8×Si?7.5×Sn+P+0.5×Pb?78.7, 60.8?f2=Cu?4.5×Si—0.8×Sn?P+0.5×Pb?62.2, 0.09?f3=P/Sn?0.35. The area ratios (%) of the constituent phases satisfy the following relations, 30???63, 0???2.0, 0???0.3, 0???2.0, 96.5?f4=?+?, 99.3?f5=?+?+?+?, 0?f6=?+??3.0, and 37?f7=1.05×?+6×?1/2+0.5×??72. The ? phase is present within the ? phase, the long side of the ? phase does not exceed 50 ?m, and the long side of the ? phase does not exceed 25 ?m.

Abstract: This free-cutting copper alloy contains 76.0%-79.0% Cu, 3.1%-3.6% Si, 0.36%-0.84% Sn, 0.06%-0.14% P, 0.022%-0.10% Pb, with the remainder being made up of Zn and unavoidable impurities. The composition satisfies the following relations: 74.4?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?78.2, 61.2?f2=Cu?4.4×Si?0.7×Sn?P+0.5×Pb?62.8, 0.09?f3=P/Sn?0.35. The area ratio (%) of the constituent phases satisfies the following relations: 30???65, 0???2.0, 0???0.3, 0???2.0, 96.5?f4=?+?, 99.4?f5=?+?+?+?, 0?f6=?+??3.0, 36?f7=1.05×?+6×?1/2+0.5×??72. The ? phase is present within the ? phase, the long side of the ? phase does not exceed 50 ?m, and the long side of the ? phase does not exceed 25 ?m.

Abstract: This free-cutting copper alloy contains 75.0%-78.5% Cu, 2.95%-3.55% Si, 0.07%-0.28% Sn, 0.06%-0.14% P, and 0.022%-0.25% Pb, with the remainder being made up of Zn and inevitable impurities. The composition satisfies the following relations: 76.2?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?80.3, 61.5?f2=Cu?4.3×Si?0.7×Sn?P+0.5×Pb?63.3. The area ratios (%) of the constituent phases satisfy the following relations: 25???65, 0???1.5, 0???0.2, 0???2.0, 97.0?f3=?+?, 99.4?f4=?+?+?+?, 0?f5=?+??2.5, 27?f6=?+6×?1/2+0.5×??70. The long side of the ? phase does not exceed 40 ?m, the long side of the ? phase does not exceed 25 ?m, and the ? phase is present within the ? phase.

Abstract: This high-strength free-cutting copper alloy comprises 75.4-78.0% Cu, 3.05-3.55% Si, 0.05-0.13% P and 0.005-0.070% Pb, with the remainder comprising Zn and inevitable impurities, wherein the amount of Sn existing as inevitable impurities is at most 0.05%, the amount of Al is at most 0.05%, and the total amount of Sn and Al is at most 0.06%. The composition satisfies the following relations: 78.0?f1=Cu+0.8×Si+P+Pb?80.8; and 60.2?f2=Cu?4.7×Si?P+0.5×Pb?61.5. The area percentage (%) of respective constituent phases satisfies the following relations: 29???60; 0???0.3; ?=0; 0???1.0; 98.6?f3=?+?; 99.7?f4=?+?+?+?; 0?f5=?+??1.2; and 30?f6=?+6×?1/2+0.5×??62. The long side of the ? phase is at most 25 ?m, the long side of the ? phase is at most 20 ?m, and the ? phase is present within the ? phase.

Abstract: This free-cutting copper alloy casting contains 75.0-78.5% Cu, 2.95-3.55% Si, 0.07-0.28% Sn, 0.06-0.14% P, 0.022-0.20% Pb, with the remainder being made up of Zn and unavoidable impurities. The composition satisfies the following relations: 76.2?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?80.3, 61.2?f2=Cu?4.4×Si?0.8×Sn?P+0.5×Pb?62.8. The area ratios (%) of the constituent phases satisfy the following relations: 2.5??65, 0???2.0, 0???0.3, 0???2.0, 96.5?f3=?+?, 99.2?f4=?+?+?+?, 0?f6=?+??3.0, 29?f6=?+6×?1/2+0.5×??66. The long side of the ? phase does not exceed 50 ?m, the long side of the ? phase does not exceed 25 ?m, and the ? phase is present within the ? phase.

Abstract: This free-cutting copper alloy contains 75.0 %-78.5% Cu, 2.95%-3.55% Si, 0.07%-0.28% Sn, 0.06%-0.14% P, and 0.022%-0.25% Pb, with the remainder being made up of Zn and inevitable impurities. The composition satisfies the following relations: 76.2?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?80.3, 61.5?f2=Cu?4.3×Si?0.7×Sn?P+0.5×Pb?63.3. The area ratios (%) of the constituent phases satisfy the following relations: 25???65, 0???1.5, 0???0.2, 0???2.0, 97.0?f3=?+?, 99.4?f4=?+?+?+?, 0?f5=?+??2.5, 27?f6=?+6×?1/2+0.5×??70. The long side of the ? phase does not exceed 40 ?m, the long side of the ? phase does not exceed 25 ?m, and the ? phase is present within the ? phase.

Abstract: This free-cutting copper alloy casting contains 75.0-78.5% Cu, 2.95-3.55% Si, 0.07-0.28% Sn, 0.06-0.14% P, 0.022-0.20% Pb, with the remainder being made up of Zn and unavoidable impurities. The composition satisfies the following relations: 76.2?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?80.3, 61.2?f2=Cu?4.4×Si?0.8×Sn?P+0.5×Pb?62.8. The area ratios (%) of the constituent phases satisfy the following relations: 2.5??65, 0???2.0, 0???0.3, 0???2.0, 96.5?f3=?+?, 99.2?f4=?+?+?+?, 0?f6=?+??3.0, 29?f6=?+6×?1/2+0.5×??66. The long side of the ? phase does not exceed 50 ?m, the long side of the ? phase does not exceed 25 ?m, and the ? phase is present within the ? phase.

Abstract: This free-cutting copper alloy contains 75.0%-78.5% Cu, 2.95%-3.55% Si, 0.07%-0.28% Sn, 0.06%-0.14% P, and 0.022%-0.25% Pb, with the remainder being made up of Zn and inevitable impurities. The composition satisfies the following relations: 76.2?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?80.3, 61.5?f2=Cu?4.3×Si?0.7×Sn?P+0.5×Pb?63.3. The area ratios (%) of the constituent phases satisfy the following relations: 25???65, 0???1.5, 0???0.2, 0???2.0, 97.0?f3=?+?, 99.4?f4=?+?+?+?, 0?f5=?+??2.5, 27?f6=?+6×?1/2+0.5×??70. The long side of the ? phase does not exceed 40 ?m, the long side of the ? phase does not exceed 25 ?m, and the ? phase is present within the ? phase.

Abstract: This free-cutting copper alloy contains 75.0%-78.5% Cu, 2.95%-3.55% Si, 0.07%-0.28% Sn, 0.06%-0.14% P, and 0.022%-0.25% Pb, with the remainder being made up of Zn and inevitable impurities. The composition satisfies the following relations: 76.2?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?80.3, 61.5?f2=Cu?4.3×Si?0.7×Sn?P+0.5×Pb?63.3. The area ratios (%) of the constituent phases satisfy the following relations: 25???65, 0???1.5, 0???0.2, 0???2.0, , 97.0?f3=?+?, 99.4?f4=?+?+?+?, 0?f5=?+??2.5, 27?f6=?+6×?1/2+0.5×??70. The long side of the ? phase does not exceed 40 ?m, the long side of the ? phase does not exceed 25 ?m, and the ? phase is present within the ? phase.

Abstract: This free-cutting copper alloy contains more than 77.0% but less than 81.0% Cu, more than 3.4% but less than 4.1% Si, 0.07% to 0.28% Sn, 0.06% to 0.14% P, and more than 0.02% but less than 0.25% Pb, with the remainder being made up of Zn and unavoidable impurities. The composition satisfies the following relations: 1.0?f0=100×Sn/(Cu+Si+0.5×Pb+0.5×P?75.5)?3.7, 78.5?f1=Cu+0.8×Si?8.5×Sn+P+0.5×Pb?83.0, 61.8?f2=Cu?4.2×Si?0.5×Sn?2×P?63.7. The area ratios (%) of the constituent phases satisfy the following relations, 36???72, 0???2.0, 0???0.5, 0???2.0, 96.5?f3=?+?, 99.4?f4=?+?+?+?, 0?f5=?+??3.0, 38?f6=?+6×?1/2+0.5×??80. The long side of the ? phase does not exceed 50 ?m, and the long side of the ? phase does not exceed 25 ?m.

Abstract: An aspect of the copper alloy sheet contains 5.0 mass % to 12.0 mass % of Zn, 1.1 mass % to 2.5 mass % of Sn, 0.01 mass % to 0.09 mass % of P and 0.6 mass % to 1.5 mass % of Ni with a remainder of Cu and inevitable impurities, and satisfies a relationship of 20?[Zn]+7×[Sn]+15×[P]+4.5×[Ni]?32. The aspect of the copper alloy sheet is manufactured using a manufacturing process including a cold finishing rolling process in which a copper alloy material is cold-rolled, the average crystal grain diameter of the copper alloy material is 1.2 ?m to 5.0 ?m, round or oval precipitates are present in the copper alloy material, the average grain diameter of the precipitates is 4.0 nm to 25.0 nm or a proportion of precipitates having a grain diameter of 4.0 nm to 25.0 nm in the precipitates is 70 % or more.

Abstract: An aspect of the copper alloy sheet contains 5.0 mass % to 12.0 mass % of Zn, 1.1 mass % to 2.5 mass % of Sn, 0.01 mass % to 0.09 mass % of P and 0.6 mass % to 1.5 mass % of Ni with a remainder of Cu and inevitable impurities, and satisfies a relationship of 20?[Zn]+7×[Sn]+15×[P]+4.5×[Ni]?32. The aspect of the copper alloy sheet is manufactured using a manufacturing process including a cold finishing rolling process in which a copper alloy material is cold-rolled, the average crystal grain diameter of the copper alloy material is 1.2 ?m to 5.0 ?m, round or oval precipitates are present in the copper alloy material, the average grain diameter of the precipitates is 4.0 nm to 25.0 nm or a proportion of precipitates having a grain diameter of 4.0 nm to 25.0 nm in the precipitates is 70% or more.

Abstract: An aspect of the copper alloy sheet contains 5.0 mass % to 12.0 mass % of Zn, 1.1 mass % to 2.5 mass % of Sn, 0.01 mass % to 0.09 mass % of P and 0.6 mass % to 1.5 mass % of Ni with a remainder of Cu and inevitable impurities, and satisfies a relationship of 20?[Zn]+7×[Sn]+15×[P]+4.5×[Ni]?32. The aspect of the copper alloy sheet is manufactured using a manufacturing process including a cold finishing rolling process in which a copper alloy material is cold-rolled, the average crystal grain diameter of the copper alloy material is 1.2 ?m to 5.0 ?m, round or oval precipitates are present in the copper alloy material, the average grain diameter of the precipitates is 4.0 nm to 25.0 nm or a proportion of precipitates having a grain diameter of 4.0 nm to 25.0 nm in the precipitates is 70% or more.

Abstract: An aspect of the copper alloy sheet contains 5.0 mass % to 12.0 mass % of Zn, 1.1 mass % to 2.5 mass % of Sn, 0.01 mass % to 0.09 mass % of P and 0.6 mass % to 1.5 mass % of Ni with a remainder of Cu and inevitable impurities, and satisfied a relationship of 20?[Zn]+7×[Sn]+15×[P]+4.5×[Ni]?32. The aspect of the copper alloy sheet is manufactured using a manufacturing process including a cold finishing rolling process in which a copper alloy material is cold-rolled, the average crystal grain diameter of the copper alloy material is 1.2 ?m to 5.0 ?m, round or oval precipitates are present in the copper alloy material, the average grain diameter of the precipitates is 4.0 nm to 25.0 nm or a proportion of precipitates having a grain diameter of 4.0 nm to 25.0 nm in the precipitates is 70 % or more.