CREATE TABLE "alloys_for_mechanical_composition" (
  "usage" text,
  "sn_sb_pct" text,
  "liquid_at_c" text,
  "casting_at_c" text,
  "remelting_at_c" text,
  "hardness" text
);

Question: What is the casting temperature for a hardness of 22?
SQL: SELECT "casting_at_c" FROM "alloys_for_mechanical_composition" WHERE "hardness"='22';

Question: What is the hardness for the alloy that is liquid at 243 degrees C?
SQL: SELECT "hardness" FROM "alloys_for_mechanical_composition" WHERE "liquid_at_c"='243';

Question: What is the Sn/Sb percentage that is liquid at 258 degrees C?
SQL: SELECT "sn_sb_pct" FROM "alloys_for_mechanical_composition" WHERE "liquid_at_c"='258';

Question: What is the remelting temperature for the alloy that has a Sn/Sb ratio of 9.5/15?
SQL: SELECT "remelting_at_c" FROM "alloys_for_mechanical_composition" WHERE "sn_sb_pct"='9.5/15';

Question: What is the casting temperature for the alloy with hardness 21?
SQL: SELECT "casting_at_c" FROM "alloys_for_mechanical_composition" WHERE "hardness"='21';