Whenever removing material the newbies should go slow and use a trial and fit process. Some of us "vets" have not followed this advice and paid for new parts, on our customer's bikes or ours... Partially chasing a pedal thread (start from the back side) AND THEN removing it to be able to check the pedal insertion is so easy to do and doesn't take more then a minute each time. A minute that might save a crank arm and your pride. Andy