Table 83.-PROPORTIONS OF ENGINEERS' HAND-WORKING TAPS, WHITWORTH'S THREAD.

Length of Screw Part in Inches.

Diameter at
Bottom of
Thread in
Inches.

Diameter of Shank in Inches.

Size of Square in

Length of

Square in

Inches.

Inches.

Pitch in Parts of an Inch.

Number of Threads per Inch.

CHANGE WHEELS TO BE USED FOR CUTTING THE SCREW OF TAP, WITH A LATHE HAVING A LEADING SCREW OF INCH PITCH.

L

3

17 18 19 19 20 21 10

11 12

Diameter of tap, in inches

Full length of tap, from end to end, in inches

Length of screw part, in inches

2847

7

217

Internal

Diameter of Pipe.

Diameter of Tap. Also the External Diameter of the Pipe.

Diameter at the Bottom of Thread.

Number of Threads

Table 86.-PROPORTIONS OF GAS TAPS (WHITWORTH'S GAS SCREW-THREAD).

Leading Screw.

Intermediate Wheel.

Stud Pinion.

Inch. Inch. Inch. Inch. Inch.

13

7

I

Table 87.-PROPORTIONS OF RHYMERS.

Inch. Inch. Inch. Inch. Inch. Inch. Inch. Inch. Inch. Inch. Inch. 3

Length of taper part from cutting end

Diameter of cutting end

32

16

15 16

116 116

32

Table 88.-WHITWORTH'S STANDARD SCREW-THREADS FOR GAS, WATER, AND HYDRAULIC IRON PIPING.

THE INTERNAL

EXTERNAL DIAMETERS OF PIPES, BEING THOSE ADOPTED BY MESSRS. JAMES RUSSELL & SONS, IN PIPES OF

AND

THEIR MANUFACTURE.