Part of Lesson Plan: Small Metal Hammer
Activity Overview / Details
Activity Notes: Students typically start work on the next day. The project will take about 10 class periods (two weeks). It is important to help students start the tap in the ¼ inch hole. This is a deep hole and students can break taps if the tap is not started properly. 1. Lay out lines using a scribe and machinist square (including marking the ¼ inch hole. 2. Cut the stock to length using a hack saw (demonstrate cutting on the waste side of the line for accuracy). 3. Using a punch and hammer make the center divit for the drill bit to rest in. This will prevent dill bit wandering. 4. Secure the material in a drill press and drill a #7 hole using cutting oil as needed (demonstrate the proper procedure for drilling on a drill press. 5. File all four sides and chamfer the striking face of the head with a bastard file regularly cleaning the file with a file card. Finish filing with a smooth file again clean file consistently. Note: Students may need to use a right angle grinder if the material is to rough for simple filing. After grinding student will need to file. 6. Using a tap, tap the hole at ¼-20 UNC. 7. Sand three sides starting with 180 moving to 320 and emery cloth. Don't do the top of the hammer at this time. You will need to do this later. 8. Polish three sides on the buffing wheels. 9. Using a ¼ - 20 UNC die, tread a 6 inches long ¼- DIA. Rod on both end. 10. Thread the rod all the way into the head so a few threads stick up though the top of the hammer head and file the threads flush to the top of the head. The threads should disappear completely leaving a seamless finish. 11. Sand and polish top of the hammer head. 12. Assemble handle and oil finish.