CREATE TABLE table_204_828 (id DECIMAL, "whitworth size  ( in ) " DECIMAL, "core diameter  ( in ) " DECIMAL, "threads per inch" DECIMAL, "pitch  ( in ) " DECIMAL, "tapping drill size" TEXT)

which whitworth size is the only one with 5 threads per inch ?
SELECT "whitworth size (in)" FROM table_204_828 WHERE "threads per inch" = 5
SELECT "whitworth size (in)" FROM "table_204_828" WHERE "threads per inch" = 5