138

To draw a stud 142

To pencil in a cap nut; pencilling for a link having the hubs on one side
only 145

Link with hubs on both sides; pencil lines for a double eye or a knuckle
joint 146

Double eye or knuckle joint with an offset; a connecting rod end 147

A rod end with a round stem 148

A bolt with a square under the head 149

Example in which the corner where the round stem meets the square
under the head is sharp; a centre punch giving an example in
which the flat sides gradually run out upon a circle, the edges
forming curves 150

CHAPTER VIII.

SCREW THREADS AND SPIRALS.

Screw threads for small bolts with the angles of the thread drawn in, and
the method of doing this 152

A double thread; a round top and bottom thread such as the Whitworth
thread; a left hand thread; to draw screw threads of a large
diameter 156

Drawing the curves for screw threads 157

To draw the United States standard thread 160

To draw a square thread 162

Form of template for drawing the curves of threads 165

To show the thread depth in a top or end view of a nut; to draw a spiral
spring 166

To obtain an accurate division of the lines that divide the pitch 167

CHAPTER IX.

EXAMPLES FOR PRACTICE.

A locomotive spring; a stuffing box and gland; working drawings of a
coupling rod; dimensions and directions marked; a connecting rod
drawn and put together as it would be for the lathe, vise, or erecting
shop 169

Drawings for the blacksmith 172

A locomotive frame 174

Reducing scales 175

Making a drawing to scale 177

CHAPTER X.