Question

Draw to scale 1:1, the front view of a vertical hexagonal bolt of diameter 25 mm. The bolt is resting on H.P. with its hexagonal head on it. Give standard dimensions.

Hint:

When drawing bolt heads, always use across-flats dimensions and indicate chamfer angles correctly with construction lines.

Answer 1

A vertical hexagonal bolt consists of a cylindrical shank and a hexagonal head at one end.
Given: Diameter of bolt (shank) = 25 mm
The bolt is placed vertically on H.P. with its head touching the base. We are to draw the front view showing the side profile.
Standard dimensions for M25 bolt:
- Across flats (hex head width) = $1.5 \times d = 1.5 \times 25 = 37.5$ mm
- Head height = $0.8 \times d = 20$ mm
- Total length of bolt = as per drawing (can assume 100 mm if not specified)
- Chamfer at head corners = 30°
- Threaded length = $\dfrac{2d}{3} = 16.67$ mm (approx.)
Construction steps:
1. Draw vertical shank with diameter 25 mm and total length of ~100 mm.
2. Add hexagonal head at the bottom, 20 mm tall, with 37.5 mm across-flats width.
3. Add 30° chamfered edges on the head.
4. Represent threaded portion at the top (if shown).
5. Add centerlines, projection symbol, and all relevant dimensions.
Label the drawing:
Title: Front View of Vertical Hexagonal Bolt (M25)
Scale: 1:1