Preparation for Demonstration; Assignment for Lesson 27—
Essentials, Sections 41, 70, 71, 72.
Demonstration—
Explain boring for screws, countersinking, use of screwdriver-bit.
Work—
Group V.
GRADE VII.
(Woodworking Group V.)
Lesson 27.
Recitation—
Screwdriver-bit? Its advantage over screwdriver? How is it kept from jumping out of groove in screw head?