This document discusses screw jacks and includes: 1) An overview of screw jacks and how they are used to raise heavy loads through small heights using square threads for power transmission. 2) Questions about the type of thread used for screw jacks, their uses, paper sizes, title blocks, and drawing sheet layouts. 3) An assembly drawing assignment to create sectional and top views of a screw jack with a parts list and bill of materials.

1. Machine Drawing
- Screw-Jack -
S.Gunabalan
Associate Professor
Mechanical Department
Bharathiyar College of Engineering &
Technology
Karaikal - 609 609.

2. Screw Jack
• Screw jacks are used for raising heavy
loads through very small heights
• Square thread is an ideal thread form
for power transmission. In this, as the
thread flank is at right angle to the
axis, the normal force between the
threads, acts parallel to the axis, with
zero radial component. This enables
the nut to transmit very high
pressures, as in the case of a screw
jack and other similar applications.

3. What is the size of A1 Size paper

4. Title Block

5. Drawing Sheet Layout

8. Screw Jack Assembly

9. Screw Jack Assembly

10. Screw Jack Assembly

11. Screw Jack Assembly

12. Part – A
Answer All the Questions
1.What type of thread is used for the screw jack
and lathe lead screw and why ?
2.Write the use of Screw Jack ?
3.What is the size of A1 Size paper ?
4.Draw the details of Title Block ?
5.Draw the Drawing Sheet Layout ?

13. Part – B
1) . Assemble all parts of the screw jack, shown in Fig. below and draw the following views:
(i) Half sectional view from the front, and
(ii) View from above
Also make the parts list and bill of materials. Dimension the view completely.