24-06-2021, 08:07 AM
It was common, in the pre-war era to bore blocks oversize by 64ths.
By the end of World war 2, we had become Americanised to some extent; the Americans had "decimalised" the inch. Rulers became available with 1/10 inch divisions and the the thousandth became the standard base unit. Somewhere I have a pair of Vernier callipers, calibrated in 1/64" increments - very difficult to read!
My set of drills however, remains in 64th increments!
By the end of World war 2, we had become Americanised to some extent; the Americans had "decimalised" the inch. Rulers became available with 1/10 inch divisions and the the thousandth became the standard base unit. Somewhere I have a pair of Vernier callipers, calibrated in 1/64" increments - very difficult to read!
My set of drills however, remains in 64th increments!